Hi this is a typical lesson learnt through hindsight. I work in pressure vessel inspection in the UK I note that many of these simple pressure vessels have a cyclic life (number of times the pressure goes up and down) for this type of unit it will be considered 500 full pressure cycles. So if you use and empty the tank every day then the life is about a year and half. Most use the compressors far less often than this in a domestic environment and so many manufacturers estimate 10 years life. A fatigue crack generated by the cyclic operation cannot be detected with a "pick" hammer, for the cost of these units it would be far safer to dispose of the unit every ten years in addition to adequate maintenance over the period. Corrosion is still a problem though this does tend to manifest as a leak. Fatigue is the probable cause here, which may have been exasperated by corrosion ( Corrosion Fatigue). Thanks for sharing and I hoe to use this video in training of vessel examiners.
I replaced mine recently and bought one with a certified tank (ASME certified I think?) and I noticed the tank steel seems to be much thicker and there are large plugs on the end, either 1.5" or 2", I'm guessing for inspection ports?
As an Engineer with over 15 years in the business, you need to fix your video. 1. NEVER, EVER hit your tank with a hammer to check integrity. If you cause a dent, it can lead to a stress concentration which can cause failure. Pressure vessels are designed for smooth walls, and ANY discontinuity affects the strength significantly. The proper way to check it is to use an ultrasonic thickness meter which use high frequency sound waves to determine wall thickness. Many states require annual inspections of pressure vessels using ultrasound for commercial applications- even hot water tanks. 2. Any signs of visual damage (dents, cracks, paint chipping off, etc) should indicate the tank needs replaced. 3. Do not attempt to repair pressure vessels of any kind. It looks like in your previous video that someone had patch welded on one side of the bung hole (drain hole), most likely because it started to crack or leak. NEVER DO THIS! If you see a crack forming, tank develops a leak, or paint starts to chip off, DO NOT USE IT! This is an indication of fatigue failure. Even if you fix the one area appropriately, it will continue to crack around and nearby anyways. More than likely this failure was due to fatigue, with rust compounding the issue. The welded seams by their very nature are physical discontinuities, and when you include the Heat Affected Zone (HAZ) causing a discontinuity in grain structure of the steel, it is a prime location for fatigue failure. Once a crack starts, it is just a matter of a few cycles to cause it to grow to catastrophic failure. Moreover, pressure vessels are only designed for so many cycles (pressurizations/depressurizations). They should be replaced periodically to ensure that things like this are avoided, even without visual damage. If in doubt, read the manual or contact the manufacturer and ask the service life of your air compressor. If the tank is expensive, it may pay to hire a company to ultrasound the tank to certify that it is still in good shape.
Your tips are great. Many thanks for them. My situation is that someone made an advertisement "I give an air compressor for free" and I went and took it. I nearly did not use it. I drained water and turned on it once and turned off it immediately. Today decided to check how it is going if it is working. It works but I did not let the pressure go above 3 bar. I turned it off. I bought a blower today just to try it. When I tried to blow dust from it the paint chipping of on top of it from the top. I was thinking to paint it with a rust protection paint. But now after reading your comment I'm afraid of using it. I started to think of buying a new one. But at the same time even new one might blow up. Would it be better if I make 1m2 whole in the ground and 1.5m dept and put it there in a steel cage?
I remember how crazy it felt to have a 4500psi scuba tank under my arm while playing paintball then remembered we have to have them hydrotested regularly to i think double the rated pressure to make sure they won't fail and I felt a lot better. I don't think anyone would ever get something like an air compressor tank hydro tested to make sure it's still safe for use.
A rupture like that in the manor it ruptured, was just a crap tank. Right from the factory. The weld looked pretty decent, the inside of the tank wasn't overly rusty. I would like to know the model and brand to submit it for recall. About the ultra sound thing, that's a great idea for everyone to do. I used to occasionally service a set of NH³ holding tanks, 500,000 gallons each. They'd have me wet blast a patch of tank and they would ultrasound it for thickness and consistency over a given area. The tanks were, at the time, about 50 years old, made in the ship yards of Oakland Ca.
heydonray this is ESPECIALLY true if you use vertical coils like he was explaining. If water builds up in the coils, it will settle at the bottom and not only eventually enter the reservoir, but water hammer it’s way through. You’d be better off just letting water coagulate at the bottom and drain it as usual.
As a former fire investigator & tank welder; I think you have more than a simple seam failure! The pressure relief valve may have temporarily stuck & contributed to the catastrophic failure; without x-rays & and a hands on inspection it is hard to be 100% certain,but from what I see in this video; I see what we call a B.L.E.V.E. or a Boiling Liquid,Expanding Vapor Explosion. Most likely your compressor ingested or inhaled a flammable gas of some type, such as gasoline vapor,propane vapor or even exhaust vapor from a running automobile,and yes even with catalytic converters, internal combustion engines still produce enough volatile fumes to do damage to a compressor like I see in your video. I don't think it was just a seam failure! Somehow your compressor got flammable fumes inside the tank & when the hot air was compressed in with the combustible vapor,that's most likely caused the explosion ! Did anyone use a spray lubricant, like WD 40 around the compressor? If so it could have sucked the fumes in and spray lubricants can explode under pressure! Sincerely Retired Captain Dean Howard. Riverside Vol.F.D. member # 11803 National Association of Fire Investigators.
You need a lot more pressure than that to cause petroleum-based oil/fuel to ignite. Even 200 psi isn't close to enough. Scuba and paintball tanks that see upwards of 3,500-4,500 psi is another story. If your standard shop air compressor lit off from fumes it would be a common occurrence. Look at the environment they live in. Auto shops, fabricating shops, etc. I guess you didn't notice the welds around the bung? That tank had been worked on at some point. Oh, and when it does happen in a compressed air tank, it's not a bleve. A bleve deals with liquid fuels. The boiling of the fuel causes an overpressure which ruptures the tank. You know, because a gas occupies much more space than a liquid. I have to question all of these youtube experts.
This guy know his tanks . Read about Dean he was a former fire investigator. So I believe he know a lot. And has paper to show it so.. some people just nag and think they know. It was a tank rupture so.... Every ones think they be an expert in welding. I got 17 years welding in pro shops. I have had like 30 different companies I worked at shit happens people . Don't say he don't know. He know a lot he was a former fire investigator... So yeah
@@jayjayshanks9892 Go watch a video of a bleve. Or a description of it. Then search what pressure is needed to ignite petroleum products without any other source of ignition. I think you'll find the answers surprising.
@@joshjablonicky171 what? Are you saying he had welded on it previously? And that's why it blew. I was wondering how much pressure it was under also? 😮
@@joshjablonicky171 All the connections and the entire tank itself are welded. It’s done in a factory in China by some kid with no shoes for pennies a day... Welding isn’t the issue. It’s metal fatigue and corrosion. It can happen to any tank, which is why this is such a relevant cautionary tale.
It may have been made in America, but if the Steel is from China, you literally have a ticking time bomb. Steel from out there cracks in areas where there is no reason to crack.
I won’t second guess your diagnosis. But it has changed the way I do things. I just retired an old compressor with a patched tank thanks to your video. Thanks
Ehh, the seam is actually the thickest part of the tank. The seam didn't fail, it failed at the seam. At 3:10 you can actually see the seam is intact, the metal split next to the seam, probably because that's where the water sat. It wouldn't sit on the seam because it's higher than the bottom of the tank.
The reason it happened was due to bad maintenance and to have kept over its expected lifetime. The reson the seem is att the bottom is for safety reason when not handled right. You can see how extremely rusty it is on the inside and how extremely thin the metal had got at the failure point, just follow the edge from the left to right and you can see how extremely thin it is where it failed which is also exactly where all the condense water gather if not let out all the time which seemed to never had happened here. It should have been thrown out a long time ago it was just waiting for something to happen.
@@turbo2ltr when welding the metal around the seam can become weaker because of the heat. It is common for metal failure to occur right next to the seam because of this. Ask a professional welder for more detail, I am at best an amateur and would never weld a pressure tank myself.
Note that the factory weld was actually clocked towards the side of the tank so that water would have needed to accumulate to a fairly substantial level to reach it. That the feed line to the tank blew off its port is a good indicator that there was some blockage/restriction in the relief valve or its port leaving over pressurization as a very likely contributing factor in this failure. The power of compressed air is very powerful and one of the worst examples happened at a commercial laundry that was over a city block in size where an entire city block was leveled by a boiler tank that got over pressurized after it ran dry and someone tried to refill the boiler manually before allowing it to cool down first. It was estimated that it only took one cup of water to develop enough pressure in a 2,000 gallon boiler to level the city block. The worker along with all the concrete around the boiler were turned to dust and vapor. This happened at least 60 to 70 if not 100 years ago at what I believe was the White Rose Laundry facility if I remember correctly and was quiet a common event, though not at this magnitude, before safety standards were put into place. An automatic condensate drain unit the vents the bottom port on the tank every time the compressor cycles on and off to me as an industrial maintenance technician is almost a critical component for a horizontal compressor to ensure continuous condensate removal and best practice is to verify its operation every day the compressor is in use along with regular checking of the pressure relief valve by manually opening it under full set pressure to ensure that even though its free that it actually vents the tank and stays open to below pump cut in pressure so if it fails to vent or fails to stay open after you release it, then that is an indication that the relief valve is in need of replacement with one with an equal or lessor relief pressure. As the tank ages you should never change to a relief that vents at a higher pressure. Coils between the compressor and the tank only better ensure that condensate ends up in the tank and does not migrate into your air system however a dog leg condensate trap with its own drain cock (preferably and auto-drain unit) after the cooling coils/device between the compressor head and the tank is a much better option as the bulk of the condensate should accumulate there and not inside the tank. Though inconvenient a steel safety cage around a compressor to contain any explosive events is best practice however is no substitute for good condensate mitigation and regular safety checks. Dinging the tank with a pick though can be a double edged sword and end up causing a failure. Sounding the tank by lightly tapping the tank with a smooth faces hammer with no sharp edges on its face after the tank has been drained completely of all pressure is a better practice as is opening the largest port on the tank and inserting an inspection camera to verify the condition of the tank. Welding a repair on a non-industrial tank is indeed an invitation for disaster unless your turning it into a non-pressurized piece of art or a barbecue. A additional danger today is that some manufacturers, for user convenience, are putting the tank drain off to the side so that you have to tip the tank in order to drain it. I've seen some where this will leave about an inch of water in the bottom of the tank if you do not tip the tank so that the drain is facing straight down and hold it there until all condensate has been removed. Indeed Be Safe. Best!
Hmm. A coiled inlet pipe might well condense the moisture out. Guess what, it will then get blown straight into the tank! Don't work. You need a proper water vapour separator which drains into a bowl that can then be emptied.
A Coiled compressor Discharge line layed flat will allow water to drop out and run to tank True,,How ever if you run the discharge line to the bottom of tank and not the top,,can hear water level in receiver as fresh compressed air bubble's in the water,,where as if you put the Dryer filter between compressor and tank,,think impulse from compressor will change how it works,,after all the air is still hot and holding moisture,Need to cool air for moisture to drop out,, Wonders has any body thought to paint in side of receiver,,be-fore use,, I Know a lot of the bigger ones are ceramic lined to stop corrosion,Mind these are made from 20mm plate,,3/4 inch for the imp guys,and coated,with big inspection holes for longevity,and rectification after inspection,, But A coat of the right paint will make all the difference,, Now Some clever bloke is gunna ask how do ya paint the inside,, remove all the fittings ,spread big sheet of plastic,, Add Paint to tank and rotate,,never said it was gunna be easy,, Tip out excess paint and let dry,,"BUT",,Must use the right paint,,as oil and other shit will cause paint to blister and cause more trouble than enough,,
Our compressor at work has a devise on the bottom of the tank connected to the drain that vents air out the bottom for like five seconds or so every few minutes....every thing else is just a gimmick. Same compressor has a built in drier, does almost nothing, still get moist air or the lines, same compressor has a coiled inlet line with aluminum cooling fins that raps around the cooling fan, again, does absolutely nothing, those last two things might be more useful in a lower demand scenario, but this compressor services both the paint booth and a cnc plasma table, both applications still require inline water separators and drop lines to trap water
You got very lucky, it might be worth seeing what the design life of a home pressure vessel actually is, and if you exceeded it. I say this because I was astonished at how short the design life of some d i y tools actually is.
I want to thank you for posting this video. I've always been a little leery about old air compressors and I have an older one than that. Because of this video I intend to use a camera to inspect both my 20 and 60 Gallon tank and am considering placing the one in use outside when I intend to pump them up. In my opinion both your videos are a must watch for all compressor owners. I always wondered why large compressors at shops were outside in a chain link fenced area instead of the shop. On my tanks when not in use I always leave the drain open.
Drain bung had welds around it, so tank had shown signs of severe rust damage, it was 'patched up' instead of being disposed of as it should have been. Who ever welded that tank up and thought it was safe to continue using even though it had already rusted though in at least one spot was and idiot.
3:05 Yep, the tank looks like it was welded. Any leaks in a tank are a sign that it has failed and needs replaced and not welded. There are a few vids popping up on YT showing exploded tanks that have been rewelded however few posting the vids realize that was a warning sign to replace the tank.
We had a used compressor (homemade from a farm) that we would regularly use to work on our cars . During the weekend we might have as many as 10 friends hanging in out all day. This air compressor exploded during the initial fill , as the contacts froze and the pressure relief valve was not working. My brother had gone in the house while it was filling. It blew out an entire wall with shrapnel everywhere. The fire department said they never saw anything like it. No one was hurt. I suggest that you NEVER purchase a used unit and do a routine safety check on everything.
Adding coiled tubing will lower compressed air temp into tank, but will not remove moisture. Moisture content in the atmosphere is what you will find entering the tank.
Yessir you are right! This is just air, not an "Ideal Gas" PV=nRT kind of thing. Have to remove moisture through an atmospheric condenser to get the water out first then run into the compressor.
Put an appendix looking Y branch at the bottom with a faucet valve to manually drain it. 2 buckets for chiller, top one is full of water, bottom one just as raiser. You can lift off the water bath, drain. Or use ice and easily swap it out. It'll heat up 5 gallons of water fairly quick. The tank stays cold. Enjoy your adventures down the plumbing aisle.
@@canuckfixit7722 the ideal gas law has nothing to do with dewpoint. The T function in that equation only deals with temperature's effect on expansion and contraction (V) or the effect on (P). However, you are correct, cooling it makes it cold humid air below its dewpoint at the higher pressure instead of warm humid air above its dew point. As a matter of fact, cooling it without drying it makes the problem worse.
Thank you for this video! I used to have an automatic drain on my vertical tank but it quit working after a while so I installed a manual ball valve into the drain line and I make it a point to manually open the drain before I turn on the compressor and at the end of the day when I turn off the compressor and I never leave the power on to the unit when I'm not present and working. This is incredible what you experienced and I am thankful you are ok. Thank you again for sharing this.
I only run vertical compressors and the drain is always slightly cracked open. I loose air, but not enough to make a difference. Self draining and if i don't hear air leaking, leads to an inspection. I also check the pressure release. I pull it under pressure and let it bleed until it resets. I've had debris come out of the the pressure release valve, so i check frequently to make sure the valve doesn't freeze up. On another note, don't neglect your water heater safety valve. Years ago a water heater blew up in our area, shot it through the roof of the building and it landed in the street. Glad to see your focus on safety.
Thank you for sharing this. I recently built a small shop. I had an area under a bench set up for my compressor. I will now be adding a small room outside to put the compressor in instead.
Thank you for posting this video. I never thought an air compressor could explode with that much force. I will definitely drain the tank and check for the number of cycles on my unit!
@@gfpd2722 I just took one very much like this (36 years old) out of service and built an out building for a much larger 80 gallon high flow upright which I pipe air underground through copper line back to the shop. I got tired of the noise and i didn't have the air capacity I needed. You are correct, my old horizontal 25-30 gallon cylinder has never been hydro tested or inspected. And, I doubt I drained it as much as I should have in recent years. I'm tempted to cut an inspection hole in the cylinder to take a look at it. I was going to give it away but having seen this, I'm going to salvage the motor off of it and recycle the rest. A home owner seeking a hydrostatic test every 5 years is pie in the sky.... it will never happen.
@@usethenoodle I'd strongly suggest cutting a hole in the tank and disable the head to make it unusable. I know someone that was given an old compressor and was hurt by it when the tank failed. He sued the guy that gave it to him and won. Old compressors become time bombs.
I have an upright Craftsman in my garage I keep charged. I’m going out right now to drain the pressure! Thank you fir this video and sharing your experience!!! Stay safe.
Look, I’m no expert but the steel in that receiver looks and sounds very thin. The fact that it let go along the weld seam is suspicious to me as well. I’m thinking that the problem isn’t rust but metal fatigue because the metal used to make the tank is so thin every time the compressor kicks in the tank expands slightly from the pressure and then contracts as you use the air. This cycle would be repeated thousands of times over ten years. If this is the case then I would fully expect it to fail at the weld seam as that is where the greatest amount of flexing would be because you have the thin metal of the tank meeting the thick metal of the weld. This would then act as a hinge point and although it’s only a tiny amount of movement given enough cycles that is where I would expect it to fracture. As you pointed out, if a pin hole developed in the tank from rust then, like you, I would expect it to just leak. Most aerosol cans run at 70 - 100 psi and I have punctured plenty of those and never had one explode. By the way, the cans have a warning not to puncture them even when empty because most of them use butane or propane as the propellant so one spark even when empty and it’s all over rover. There’s a good reason they use those gasses but that’s another story. It might be worth your while running a magnifying glass over the point of failure to see if there are any signs of a rust hole but I’ll be surprised if you find one. I think once the seam had failed the sudden release of air was big enough to rip the tank apart like a balloon popping where as when you get a pinhole there is enough metal around the hole to stop the rest of the tank from tearing open. I wouldn’t mind betting that it’s a cheap Chinese compressor. Do yourself a favour and buy a decent quality American made unit. I have two Australian made compressors in my workshop, a triple cylinder I use for sand blasting and a twin cylinder I use for everything else. Both compressors have tanks that have a 50mm plug at each end that can be removed to allow cleaning and inspection of the tank. I service them once a year and each time I take the compressor outside, remove the plugs and clean out the tanks. I even have a wire brush on a stick so I can clean the gunk off the bottom of the tank and eye ball the inside. Something to watch out for is that I have noticed some of the quality brand names here are now using Chinese compressor pumps and electric motors and maybe even tanks for all I know and assembling them here and whacking “made in Australia” stickers on them. I hope what I have said makes sense and I am happy to be proved wrong so please let me know what you find. All the best and stay safe. Cheers Stuart 🇦🇺
@@charlessmith833 Hey Charles, you are so right. I avoid buying Chinese as much as I can, even though it means digging deeper into my pocket sometimes it my little protest. Cheers Stuart 🇦🇺
@@chisza777 Hi Mark, I have two compressors running together but off different circuits for sandblasting and both are Com-Pac units made in Brisbane and running Clisby pumps. I also have my original workshop compressor, a Peerless made in Adelaide. Why do you ask? Cheers Stuart.
Thank you for posting this.. I replaced a similar compressor. I was afraid it would fail. I then drilled holes through the compressor head and cut a hole in the tank. This was to prevent someone else from salvaging it. I could then see inside. The entire bottom was heavily rusted. Draining doesn't prevent corrosion. It just keeps the condensation out of your tools. If you live in a humid area, your tank will fail sooner. They hydro (water under pressure) test air compressor tanks for rating them for this reason. Water will dissipate the pressure in the event of a leak very quickly; compressed air releases energy (pressure) slowly. Hydro testing is MUCH safer.
Hydrostatic testing can result in VERY violent energy release. Hydrostatic testing of tanks and cylinders is usually undertaken in a containment vessel in case of violent release. Watch some videos of failed hydrostatic tests.
@@stanflahaut1893 when you fill the tank with water then plug in a 250 PSI air compressor (double its nominal max pressure), very little energy is actually stored in the tank - If it fails, it will simply leak.
Thank you for the info I had no idea👍 My compressor is a Montgomery Wards about 45 years old. Years ago I removed the safety valve and welded a plug in so I could get 275 out of it and get max performance from my impact and fill a car tire in under 30 seconds. But thanks to your video I've duck taped a blanket around the tank for safety. Thanks again!
Possibly the weld was a little porous from new and allowed rust to get into the seam and weaken it. As you said tanks usually get pin holes and just rust into uselessness. I have a huge commercial compressor where the tank rusted through I tried to patch it and found I was chasing the rust so it is junk. I picked up a vertical tank and found it was cracked where the compressor mounted on the top. I welded it BUT after seeing this it is going to get flattened and loaded in the scrap dumpster. Thank you for taking the time to post this. I am in the logging business so hazards are a way of life however if I am tempted to take a short cut I remind myself that it will take less time to stop and do it safely than to even get to the emergency room.
My brother in law had a similar sized vertical compressor. They probably never or rarely used the drain TBH. The bottom with the water finally rusted out and let go. The tank was in the corner of their garage and shot off vertically like a rocket and blew completely through the garage roof and landed some distance from the garage. So a vertical tank is just as likely to let go as your horizontal one.
Sir, thank you for sharing this. This post may save a life in the future. I have several compressors and one is a Craftsman about the size of yours. This one I use for sandblasting and the cabinet is about six feet from the compressor. Well it won't be in the future. I'm getting it as far from me as I can. Something to point out is that the metal adjacent to any weld, which is referred to as the Heat Affected Zone (HAZ) undergoes a change in the grain structure as a result of the high heat. When a weld fails, it is generally in the HAZ if the weld is not stress relieved; known as post weld heat treatment. This would have been the manufacturer's fault had they skimped on this step.
these tanks can be pressure tested with a gauge and a pressure washer pump. typically tests should be minimum 1.5 x max working pressure. if it fails it fails. if it dosnt you can now be confident the tanks not going to rupture under normal pressure and they should be tested every x amount if years(idk the number). its called a hydrostatic pressure test iirc
These were really fascinating videos. Far too many people crap on safety precautions, and in many instances I'm one of them too, because you think, it's never going to happen to me. These videos have given me new appreciation for why those precautions exist in the first place. Thanks for sharing.
Funny how you never mentioned the additional welding that was clearly evident in the other video, also at about 7:43 the tank looks very thin with severe corrosion. Its great that you posted this video and the other, we all need reminding just how dangerous these things can be.
me and my father build cars in our garage, have an air compressor he bought new in the 80's. It is a vertical unit, but now I will definitely get on board to build a little closet outside the garage like he's been going on about for years. Glad you and your son are okay, I'd be lost without my old man
Make sure your compressor has a "code" tank, it will have a stamp welded on it. That receiver looks awfully thin! Glad no one was hurt! That was basically a bomb going off. Must have sounded like a depth charge.
That is more like bad piston rings and compressed oil mist. As back pressure increases, oil mist in piston begins to diesel, flame runs back along the line into compressor tank and ignites the oil vapors inside there, like a giant spud gun without barrel. Tank explodes because no way to get the pressure out. Btw, seems to happen most often with cheap single stage compressors, high compression ratio makes piston blowby and dieseling much more likely. Failure at the seam is only because it's the weakest part on the tank, not because it was compromised. Look at the yielded areas next to the seam, that wouldn't happen because of rust, only a short, massive rise in pressure does that. Seam is only what gave up eventually.
I went to one industrial site, where the vertical 2,000 gal tank, was almost 1/2 way FULL of water - It had an automatic drain that had become plugged with rust particles, so it would not drain at all. The company discovered this when the compressor stopped, an a fountain of water gushed out of it (piping to the tank, entered near the bottom).
"Pressure Kills" - I remember my brother telling me this when he took me to my first oil well fracking job. He also said "Complacency kills" and said that we would likely see a lot of people casually walking around but that we should be mindful and speak up when ANYTHING looks or sounds odd because that's often how people get killed, they underestimate the danger they're in.
I have watched both your compressor videos , thanks for sharing , I had never seen this before and have shared to friends with compressors. Glad no one was hurt , you were very lucky as it was easily able to kill, like you say imagine it under a bench covered in tools such as files etc and that happening. Thanks for posting a very informative video for everyone's safety benefit 👍
The manual lift on a safety valve is to check that it's not seized. The valve needs to be removed and tested against a calibrated pressure gauge to see if it lifts at the set pressure. Inspection of pressure vessels, requires a thorough visual inspection inside and out together with an ultrasonic thickness test at various points of the vessel.
This is a good demonstration why commercial units have line dryers, aftercoolers, and automatic drains. My commercial Chicago Pneumatic compressor vents all water out of the tank every hour. You can purchase these automatic bleeders for about $100 and set them from 20min to a few hours, usually.
Wow! I'm glad you are ok! I've been In shops for 40+ years and never seen this. We don't think about, being older folks, how much cheaper things are made. Think 1960s Chevy compared to 2000s Chevy. As older folk we have been made too comfortable with things manufactured today. On that note I have an 80 gallon upright compressor against the wall in my garage. It's going to get its own little house on the outside. Be safe and have fun! Terry from South Carolina
One other safety note on air compressors is the lines and fittings should also be to standard. The hose fittings can come off and whiz like a bullet around the shop if not secured with the proper clamps. Back in the day, the tanks were made of thicker sheet metal and failure would be in the form of a pinhole that would leak and render the tank for scrap. Thanks for sharing and take care folks.
On one thing you were very wrong, the hot air IS NOT the moist air, just the opposite. Relative humidity of air actually drops and air gets ''dryer'' as it gets hotter and cooling it down will just increase it's relative humidity and consequentially as it gets above 100% condensation will start to form and pool on the bottom. The thing is when air gets compressed it's relative humidity also rises up and that is what causes condensation of water in compressor tank. Lets say it like this for example, you have air, it gets drawn into the compressor, gets compressed and exits as HOT air with maybe even LOWER relative humidity than before BUT as it cools down in the tank that's when humidity rises and condensation forms. Therefore whether you cool it down quicker with additional pipe length before tank OR in the tank alone doesn't make any difference at all.
Well one thing I can say is adding that extra tubing will let the air cool down and condensate leaving behind the moisture. Just like a cold glass of water sweating. But you would have to drain the tube out. In this case you would rather water in the tube then the tank because the tank can blow up as you have seen in the video. This will not eliminate the problem but have the tank last longer. Thanks for the comment and hope you enjoyed!
Air's ability to hold moisture is relative to it's temperature, that why it's called relative humidity, it's a measure of how much water vapor the air can hold based on how much water vapor is currently in the air, relative to it's temperature. If you increase the air's temperature, you increase the ability of that air to hold more moisture, hence you lower it's relative humidity, but the amount of water vapor (all things equal) is the same. The dew point is a better indicator of how much moisture is in the air. The dew point temperature is the temperature at which the air is totally saturated and can no longer hold moisture. The higher the dew point temperature, the more water vapor in the air. As you compress air, you increase it's temperature and it increases it's ability to hold more water vapor, as the compressor runs, you add more water vapor that comes from the ambient air. Because the compressed air is warmer, it can hold that additional water vapor and the dew point increases. But as the compressed air inside the tank cools, it reaches it's dew point temperature, and condensation forms inside the tank. Coiling the feed line in the tank causes the condensation to happen in the line and not in the tank, the water in the coiled line will be pushed into the tank. Compressors with coiled feed lines still need to be drained.
@@3generation_racing658 water is literally squeezed out of the air being compressed,no way around it all you can do is drain it out after the fact. They sell electric timed gizmos you hook up to your drain and let the water out at an adjustable interval,just the thing to minimize rust in the tank. On a side note like others have said that tank is super thin looks to be about 060 thick or1.5 mm should be more an eighth inch thick. I’m sure you’ll replace it with a higher quality unit preferably made in USA.
@@3generation_racing658 The condensate will just get pushed along the tube and into the tank. It won't just sit in the tube. And by the way, rolling a coil of tubing it probably not a good idea. That length of tube is kept short and simple for a reason. The only way to dry the air is to use a pressure swing adsorption column and molecular sieve to pull the water out. They are usually set up in tandem so one column is drying the air and the other is either regenerating or waiting its turn. When you take ambient air, even at a relatively comfortable 50% relative humidity and compress it from 15 psia (absolute pressure) to 115 psia (absolute, or 100 psig), you squeeze the volume down by a factor of 7.66. Since the humidity of the air is based on how much mass of water there is per unit volume, you now have air at almost 385% relative humidity once that air cools to room temperature. You can count on getting water in the tank.
Thanks so much. If I ever buy another compressor, I will most certainly check to see where the seam is. That should not have happened, but it did. You are extremely lucky or blessed. It might be a good idea to bring this up to every seller of compressors in the world.
I think there is a mistake in your understanding about moisture. Moisture is not "produced" during compression in the cylinder. The absolut amount of water is still constant. It starts to condensate in the tank, most of it, when you use the air, therefore the tank is cooling down according to a decrease in temperature of the air (because of expansion). Therefore the cooling of the compressed air before entering the tank will not help to prevent the moisture!
Well done video. Good follow up explanation. Good point. NEVER WELD AN OLD COMPRESSOR TANK! money saved vs family lost...hell of a thing to live with after...
@@terrismith9095 the inc carterages i agree but welding the tank weakens the metal becouse of the heat and sure it will hold but for how long and do you want to risk jour life for a replacment tank?
Great warning I will be passing on to all my techs tomorrow. I totally agree with the idea of completely draining the tank at end of shift. Hard to believe that one was only 10 years old. I also appreciate the fact you weren't pointing fingers at the manufacturer. Wishing you all the success moving forward and thank you. Liked and subscribed.
Thanks. I have worked with compressors, cylinders of compressed gases and with large dewars of compressed liquified gasses. Only in one workplace did they have the units outside the work area and outside of the building. Even university administrators and safety officers did not change and move the compressed gasses or compressors outside the building. After seeing the damage your compressor did, I suspect that such a compressor explosion would cost in excess of $50,000, perhaps $100,000, maybe more in the laboratories where I worked. Scientific instrumentation is expensive. Thanks again for your videos.
It is very nice of you to share you experience. I was about to purchase an used air compressor and your video reminded me that the tank on an air compressor is a pressure vessel. Pressure vessels can be very dangerous when not used or maintained properly. First and foremost there it proper use and maintenance. Manufacturers recommend draining after every use, and checking the operation of the PRV often. I am not sure how high of a pressure setting was being used, but it is good to keep is only as high as needed. I have a personal unit that I never let get pass 90 psi, even thought he unit is rated at 175 psi. Still 90 psi is high enough that it can kill someone. I will be more careful when using my compressor moving forward. Finally, in your first video you mentioned ear drums... Yes. It is good idea to use hearing protection when working with air compressors and pneumatic tools. I had a friend who die when a tire with 90 psi blew next to him. What killed him was the sound which blew his drums. Be safe out there.
you don't drain it regularly. you drain after using it every day. you want to avoid the air inside to condensate. also the drain valve should be left open and close it only when ready to use the compressor again.
I was taught years ago to leave the drain petcock slightly open at ALL times, even while compressor is running. It only needs be be a small “leak” to prevent condensation from remaining in the tank. This came to me from a former major brand race car engineer.
@@scylla_39 Sure! All compressor tanks (as far as I know anyway) have a valve on the tank. Usually this valve is placed at the very bottom of the tank. This valve is used to drain ANY accumulated moisture in the tank. Most people will close this valve. They close it to keep the compressor from cycling while it is being used. Wean the valve is closed moisture accumulates inside the tank ABOVE the valve. You are to then drain the tank by opening the valve when the compressor is turned off to drain any moisture. Many people will then close the valve until the next time they use the compressor and need to drain it again. What I was taught is that drain valve should ALWAYS stay slightly open. You should hear a small hissing sound whenever the compressor is on. You may not be able to hear it if the compressor motor is running. As long as that valve stays open, and you hear the hissing sound, NO moisture can accumulate as it is immediately blown out the valve, thus preventing (or at least reducing the amount of) corrosion (rust if steel). Check in the manual for the compressor, it should tell (and maybe show) where the drain valve is located. PLEASE NOTE: this ONLY works where the compressor that is being used has the valve at the VERRY BOTTOM of the tank when it is running. MAKE SURE that the compressor is in the proper position. If it is NOT properly positioned there is an almost certainty that the MOTOR will FAIL as it will not be getting proper lubrication. (If is a vertical compressor use it vertically. If it horizontal us horizontally. )
@@bobscott1315 Sounds like a great idea. Leave drain plug slightly open during use and I suppose when not in use. Then you may not need to open drain fully at all.
@@bobscott1315 What was his thinking on that? Is there a danger of the condensation becoming heated enough to have like steam power or pressure added above and beyond the tank cut off pressure? I was just looking at a temp/steam pressure chart and it would take a temperature of 338 degrees F to build 100 PSI of steam pressure in a boiler.
Thanks for sharing. Glad you're ok.And coming time to check all things in my compressor even is used only 2 years. For that cracked tank need more than 25bar even with rust from years of use.thanks
Hi,thanks for a very interesting video,before retirement I worked in Garage Equipment and all receivers/pressure vessels were inspected every 24 months.This Inspection consisted of removing pressure gauge and pressure relief valve and testing them hydraulically using a water pump.The vessel was opened up at the end and inspected visually.Readings were then taken 4 readings from the top,4 readings from the bottom and 4 from each side using an ultrasonic tester.In my experience the older vessels were built to last normally 1/4 thick and apart from slight pitting internally would last up to 40 years.Unfortunatly more modern units typically manufacturerd in Italy or China start life at about 3mm and you are only allowed 0-50mm deterioration.I would be interested to know where your air tank was manufactured.I’m in the UK buy the way
Im in the uk also, and am an examiner of pressure systems through the British compressed air society (BCAS), also a member of the institute of mechanical engineers. I agree with what you have said, especially about where the receiver was made. In the states they build to asme 8, these are not legal in the uk or eu as the standard is not deemed safe. Anything made in china with a CE marking may not actually mean it’s eu or uk legal as this mark also stands for Chinese export, be cautious. The mention in the video saying the relief valve was ok is bs. Pulling the releasing gear doesn’t prove it’s reliving at the correct set pressure, only a test with a calibrated gauge will tell you this! And do not pull the easing gear before the test as this could actually prove it safe whereas before you did this it may have been stuck ( your fingers / eyes etc are not calibrated!). If this compressor went over pressure to blow, would mean that the prv (pressure relief valve/ safety valve) and the pressure switch were both faulty, plausible but I would be falling on the side of poor maintenance , receiver construction and inadequate design for safety.
This is a great video, at my shop I was afraid something like this could happen that's when I bought a brand new 1,000 gallon propane tank and I use a V-4 air compressor also I installed and car ac condenser and a dryer and after every shift the tanks is opened up and drain any water then in the mourning they run it for 10 minutes before closing the drain valve.
Cooling the air does not remove the moisture. The coil only serves to reduce temperature and condense the moisture. How much metal eroded? What's the thickness loss from rust versus the clean steel. How do you know the pressure release works? All you showed was the valve moved. You didn't prove the passage was clear.
I had o furniture factory for 30 years I have hear of this happening. The Gov. regulations hear in Brazil obligate that you have to have the tank checked pireadactley with a hydrostatic check, first on installation, second 5 years, third 7 year, fourth 9 years, then every year and discard at 20 years. A log book has to be kept and updated every intervention that is made to the compressor unit. A hydrostatic test is made by taking off and capping all access to the tank but one. On this one access point is connected a hand pump and with gage and pumped to 2 X the nominal working pressure for 1 hour.
WOW,good video.Thank you for posting this as a public service. I have the same compressor.BUT mine is copper brownish looking and it has the craft**m lable with a cert tag welded on it. I remember when i bought it in 1980? they had 2 versions.The red like yours and the brown one with the cert.Lots of times back them s**rs had two versions of tools etc.the red stuff was the cheaper ,then they had craft**M brand with like a lifetime guarantee on tools and battery's and stuff.REGARDLESS of this ANYONE that has an air tank NEEDS to be aware of the dangers of maintenance and regular inspection.JUST like the water hoses on your car,THEY wear out FROM THE INSIDE,making it much harder to see a failure coming.I'M going to send a link to my friend in INDIA,he repairs trucks there and they PATCH EVERYTHING.MAKES me queasy just thinking about it.GREAT VIDEO,thanks again.THIS is going to save a life.
thank you for the PSA. eye opening. i have heard a million times a pressure vessel is dangerous but i never thought a home gamer unit could do this much . crazy!!!
I have a tank in my garage that is pressurized all the time and I’m going right now to drain the tank. What a wake up call. Glade you are alright man and I’m going back to the previous video and edit my comment
The main thing is to drain the water out regularly. The petcock they come with are junk, I replaced the petcock on mine with a ball valve, it has a much bigger opening. I also piped the drain to the side so it's easy to see and get at, that way you do it more often.
Mine’s just ten years old, domestic, not much work done. Frequently drained, tank slightly inclined toward drain. Opened up inspection bush. Plenty of wet rust, so draining is far from the solution. No second guessing this... replace now!
Yes Micheal, a coil to cool the air between compressor and tank will just condense the water in the coil and it will just dribble into the tank. Ya gotta dry the air before it is drawn into the compressor, and that isn't easy or cheap.
Your pressure reg failed. Yes, you can manually pull the release BUT it doesn't take much for it to stick. I've seen HVHP compressors fail. You were lucky and isolating your compressor from your workspace is a great idea
Thank god no one got hurt, count your blessings, this was just a warning to you and all of us now that you've posted it! For that I thank you..I'm now going to order one of those £8 inspection cameras that looks like a Dr's endoscope and have a good look around inside my tank!
They make racing blankets for transmissions,and intake manifolds with blowers.I wonder if any of this could be used on a compressor to contain any metal shrapnel from an explosion?Thanks for sharing this danger.
I was a compressor engineer for many years and have never seen anything like it, yes i've seen them crack and release the pressure, this must have gone way over pressure, i've opened hundreds of receivers for insurance inspection and they all have rust, a dent in the receiver will automatically cause it to fail but very rarely do the fail because of the rust, an auto drain fitted to the receiver is best option electronical solenoid types that you set to blow off for a few seconds every couple of hours are cheap.
Thank you for sharing! Really! Never would have thought of that happening. These tanks should have an expiration date, similar to propane tanks if you think of it.
Most people have zero idea how much force they are dealing with in an air compressor. As a professional in the pressure vessel industry, I've often had to do the math for people. That tank has roughly a 17.5 square foot area using the numbers I found on Husky's website. Multiply that by 144 (square inches in a square foot) and then multiply that number by 100 pounds per square inch, and you get 252,000 pounds of force, or 126 TONS of force on the inside of that tank. That's why when it blew up it did so much damage. Looking at it from my perspective, knowing the forces involved, it actually wasn't all that much damage. The owner got off VERY lucky losing a garage door track, some speakers, and all the glass in the garage. We get very complacent around pressure vessels because we're used to them. It's the same complacency that we get while we're tooling down the highway at 70 MPH. It feels normal, so we don't think about it. But put the car sideways in the rain and suddenly we remember that we're moving VERY quickly. Realistically there's nothing you can do to prevent this except to look carefully at your tank. I don't recommend beating on it with a hammer, but tapping gently might reveal cracks. Just remember that you're trying to FIND damage, not CAUSE damage. Drain your tank regularly, just as the owner says. And if you're not perfectly happy with the state of your compressor, junk it and buy a new one. As the owner says, if his son had gotten up early to work with him, he'd have been standing right next to it when it blew. Compressors are expensive, but nothing compared to losing a son. The owner is ABSOLUTELY correct that you should NEVER weld a tank. If you do not possess the required pressure vessel welding certifications, you're just going to make the tank weaker. DO NOT WELD PRESSURE VESSELS!!! I can't stress this enough. It's actually illegal as well as weapons grade stupid.
Tanks pretty much have a limited life, and emptying them only helps so much. Wet steel rusts faster than steel that is entirely underwater, so it's always gonna rust.
Thanks for posting! I've got a 25yr old compressor about the same size that recently started springing some pinholes in the bottom, it looks like I need to replace it sooner than later! Such a shame too because the rest of it still works perfectly fine.
Our guy was asking for this to happen. 3:05 The tank looks like it was rewelded around the drain fitting. Any leaks in a tank are a sign that it has failed and needs replaced and not welded. There are a few vids popping up on YT showing exploded tanks that have been rewelded however few posting the vids realize that was a warning sign to replace the tank.
Thanks. I've got an old compressor that has been siting out in the shed for about 20 years that I'm always thinking about digging out an firing up. Not any more.
Well you can check the expiration date that's stamped into the side of the tank. If it's expired by more than 5 years then it's kinda not a freak accident. Standard lifespan for an air tank is 10-15 years. All legitimately manufactured and sold air tanks have an expiration date.
The skin of that air receiver looks very thin. I reckon that compressor was a cheapy. I have worked with and built a number of air compressors and am pretty sure that was your problem. Just the first bit of rust along that seam and it was ready to explode. Putting the seam to the top presents problems of its own. You will see decent manufacturers put the seam at the 5 o'clock or 7 o'clock position. Be glad no-one got injured.
Yes we think the combination of rust and the seem on the bottom where water will collect was the main factor to the blow up. We also think the tank was thin too, which didn’t help. Thanks for commenting and be safe!
Tanks have been getting thinner and thinner steel wise. The postal service in the UK bought a truck load of this type of compressor so they could pump up the van tires. After there first safety inspection the lot got scrapped. Tanks were that thin steel wise the insurance inspector condemned them. Made in China.
I have this identical compressor. It's a Husky from 1999. It was my dads and I inherited it about 6 years ago. I drain it all the time and I even take off the air filter and spray WD-40 into the intake every other month to keep rust from biulding up inside
Careful, wd40 spray is explosive, you probably don't want compressed explosive gas in a compressor tank. Spray it over a lighter and you'll see for yourself.
3:05 Yep, the tank looks like it was welded. Any leaks in a tank are a sign that it has failed and needs replaced and not welded. There are a few vids popping up on YT showing exploded tanks that have been rewelded however few posting the vids realize that was a warning sign to replace the tank.
Every time I look at my compressor I think "1000lb bomb" i just had my pressure switch fail and the new replacement I lowered the cut off pressure just in case! Real glad no one got hurt.
There should be a pop-off valve in the system as well. I run 180psi at my shop, that's a commercial grade compressor and 80 gallon tank though. Every few years a guy comes out to test it ultrasonically then issue me a new "permit to operate pressure vessel."
I was thinking about the vertical versus horizontal thing, I'd think a vertical (or even one of those little "pancake" ones) would be less likely to explode like this from corrosion not due to the weld seam but because water would collect in a puddle in the bottom, a spot, rather than a line along the entire bottom. Regardless of where the weld seam is, if water creates a line of rust along the bottom that would create a seam that could blow. A small spot would blow out less catastrophically. That's my guess anyway, couldn't find anything written about this. As for the cooling loops in the line, that wouldn't help - it would condense water out of the air before getting to the tank rather than inside it, but water is still ending up in the tank.
Good warning. Perhaps I have been too cavalier as well. One of few actual examples I have seen of a catastrophic failure on a small unit with no external factors.
I appreciate the comment. The correct way to do it would be to sonic test it but most people don’t have one. So another way would be to ding it. That way you know if the tank is compromised. Just make sure you drain all the air out! Thank you.
@@3generation_racing658 Best way is to hydraulic test it, to at least 1.5 times working pressure. It will find faults that sonic misses, and if it passes you can put it anywhere you like or stand right next to it without fear.
@@3generation_racing658 I have an Ultrasonic thickness tester, bought on Ebay for $85. I tested all my air tanks with it, and also hydro-statically tested them. And I'm still leery of the older ones even at 120 psi.
@@3generation_racing658 What is the brand name for this compressor? It looks like a Craftsman paint job but no name on the tank that I could see. The tank appears to be very thin walled so no wonder it tore apart so much. I thank God that you and your son weren't hurt.
I live in the UK. I have worked in the air compressor industry on a USA air base in the UK. UK law require inspection of receivers for insurance. My job was to do these inspections. All fitting are removed from the receiver and it is then filled with water a pump is attached and a pressure of 1.5 times the max working pressure is pumped into the receiver. All welds and seams are taped with a hammer and inspected for leaks. If ok the working and test pressure are stamped on the receiver with the date. Large revisers have inspection plate which must be removed. Water dose not compress!
Hi this is a typical lesson learnt through hindsight. I work in pressure vessel inspection in the UK I note that many of these simple pressure vessels have a cyclic life (number of times the pressure goes up and down) for this type of unit it will be considered 500 full pressure cycles. So if you use and empty the tank every day then the life is about a year and half. Most use the compressors far less often than this in a domestic environment and so many manufacturers estimate 10 years life. A fatigue crack generated by the cyclic operation cannot be detected with a "pick" hammer, for the cost of these units it would be far safer to dispose of the unit every ten years in addition to adequate maintenance over the period. Corrosion is still a problem though this does tend to manifest as a leak. Fatigue is the probable cause here, which may have been exasperated by corrosion ( Corrosion Fatigue). Thanks for sharing and I hoe to use this video in training of vessel examiners.
500 full cycles? i'll have to remember this. thanks for posting.
I replaced mine recently and bought one with a certified tank (ASME certified I think?) and I noticed the tank steel seems to be much thicker and there are large plugs on the end, either 1.5" or 2", I'm guessing for inspection ports?
I had no idea! Thank you for saving lives!
500 cycles. I've put at least 200 cycles in the 13 years I've had mine, that's after my grandfather owned it for 35 years before that.
Maybe I should put a mark on the tank every time I use it to count the number of cycles.
As an Engineer with over 15 years in the business, you need to fix your video.
1. NEVER, EVER hit your tank with a hammer to check integrity. If you cause a dent, it can lead to a stress concentration which can cause failure. Pressure vessels are designed for smooth walls, and ANY discontinuity affects the strength significantly. The proper way to check it is to use an ultrasonic thickness meter which use high frequency sound waves to determine wall thickness. Many states require annual inspections of pressure vessels using ultrasound for commercial applications- even hot water tanks.
2. Any signs of visual damage (dents, cracks, paint chipping off, etc) should indicate the tank needs replaced.
3. Do not attempt to repair pressure vessels of any kind. It looks like in your previous video that someone had patch welded on one side of the bung hole (drain hole), most likely because it started to crack or leak. NEVER DO THIS! If you see a crack forming, tank develops a leak, or paint starts to chip off, DO NOT USE IT! This is an indication of fatigue failure. Even if you fix the one area appropriately, it will continue to crack around and nearby anyways.
More than likely this failure was due to fatigue, with rust compounding the issue. The welded seams by their very nature are physical discontinuities, and when you include the Heat Affected Zone (HAZ) causing a discontinuity in grain structure of the steel, it is a prime location for fatigue failure. Once a crack starts, it is just a matter of a few cycles to cause it to grow to catastrophic failure.
Moreover, pressure vessels are only designed for so many cycles (pressurizations/depressurizations). They should be replaced periodically to ensure that things like this are avoided, even without visual damage. If in doubt, read the manual or contact the manufacturer and ask the service life of your air compressor. If the tank is expensive, it may pay to hire a company to ultrasound the tank to certify that it is still in good shape.
Excellent tips. Thank you!
Your tips are great. Many thanks for them. My situation is that someone made an advertisement "I give an air compressor for free" and I went and took it. I nearly did not use it. I drained water and turned on it once and turned off it immediately. Today decided to check how it is going if it is working. It works but I did not let the pressure go above 3 bar. I turned it off. I bought a blower today just to try it. When I tried to blow dust from it the paint chipping of on top of it from the top. I was thinking to paint it with a rust protection paint. But now after reading your comment I'm afraid of using it. I started to think of buying a new one. But at the same time even new one might blow up. Would it be better if I make 1m2 whole in the ground and 1.5m dept and put it there in a steel cage?
I remember how crazy it felt to have a 4500psi scuba tank under my arm while playing paintball then remembered we have to have them hydrotested regularly to i think double the rated pressure to make sure they won't fail and I felt a lot better. I don't think anyone would ever get something like an air compressor tank hydro tested to make sure it's still safe for use.
Very informative, thanks for the tips
A rupture like that in the manor it ruptured, was just a crap tank. Right from the factory. The weld looked pretty decent, the inside of the tank wasn't overly rusty.
I would like to know the model and brand to submit it for recall.
About the ultra sound thing, that's a great idea for everyone to do.
I used to occasionally service a set of NH³ holding tanks, 500,000 gallons each.
They'd have me wet blast a patch of tank and they would ultrasound it for thickness and consistency over a given area. The tanks were, at the time, about 50 years old, made in the ship yards of Oakland Ca.
Glad you’re ok! Please note that simply cooling the compressed air before it reaches the tank will NOT prevent water from entering the tank.
heydonray this is ESPECIALLY true if you use vertical coils like he was explaining. If water builds up in the coils, it will settle at the bottom and not only eventually enter the reservoir, but water hammer it’s way through. You’d be better off just letting water coagulate at the bottom and drain it as usual.
@@johnwieliczko6195 what this guy said. This is just as important if not more than anything in the actual video.
Came here to say same thing.
Yes! I was expecting him to say something like: "then connect a valve that leaks out a bit of air and most water before it enters the tank"
A dryer?
As a former fire investigator & tank welder; I think you have more than a simple seam failure! The pressure relief valve may have temporarily stuck & contributed to the catastrophic failure; without x-rays & and a hands on inspection it is hard to be 100% certain,but from what I see in this video; I see what we call a B.L.E.V.E. or a Boiling Liquid,Expanding Vapor Explosion. Most likely your compressor ingested or inhaled a flammable gas of some type, such as gasoline vapor,propane vapor or even exhaust vapor from a running automobile,and yes even with catalytic converters, internal combustion engines still produce enough volatile fumes to do damage to a compressor like I see in your video. I don't think it was just a seam failure! Somehow your compressor got flammable fumes inside the tank & when the hot air was compressed in with the combustible vapor,that's most likely caused the explosion ! Did anyone use a spray lubricant, like WD 40 around the compressor? If so it could have sucked the fumes in and spray lubricants can explode under pressure! Sincerely Retired Captain Dean Howard. Riverside Vol.F.D. member # 11803 National Association of Fire Investigators.
Good info . Good man thanks Dean you got brains bro
You need a lot more pressure than that to cause petroleum-based oil/fuel to ignite. Even 200 psi isn't close to enough. Scuba and paintball tanks that see upwards of 3,500-4,500 psi is another story. If your standard shop air compressor lit off from fumes it would be a common occurrence. Look at the environment they live in. Auto shops, fabricating shops, etc. I guess you didn't notice the welds around the bung? That tank had been worked on at some point. Oh, and when it does happen in a compressed air tank, it's not a bleve. A bleve deals with liquid fuels. The boiling of the fuel causes an overpressure which ruptures the tank. You know, because a gas occupies much more space than a liquid. I have to question all of these youtube experts.
This guy know his tanks . Read about Dean he was a former fire investigator. So I believe he know a lot. And has paper to show it so.. some people just nag and think they know. It was a tank rupture so.... Every ones think they be an expert in welding. I got 17 years welding in pro shops. I have had like 30 different companies I worked at shit happens people . Don't say he don't know. He know a lot he was a former fire investigator... So yeah
@@jayjayshanks9892 Go watch a video of a bleve. Or a description of it. Then search what pressure is needed to ignite petroleum products without any other source of ignition. I think you'll find the answers surprising.
@@jayjayshanks9892 Here is a bleve. An air compressor in no way, shape, or form, can be called a bleve. ua-cam.com/video/UM0jtD_OWLU/v-deo.html
Thank you for caring about other peoples lives and the time that it took to make this video
Just not about there own. They have welded on the drain plug. Caused fatigue it blew up.
@@joshjablonicky171 what? Are you saying he had welded on it previously? And that's why it blew. I was wondering how much pressure it was under also? 😮
@@joshjablonicky171 All the connections and the entire tank itself are welded. It’s done in a factory in China by some kid with no shoes for pennies a day...
Welding isn’t the issue. It’s metal fatigue and corrosion. It can happen to any tank, which is why this is such a relevant cautionary tale.
It may have been made in America, but if the Steel is from China, you literally have a ticking time bomb. Steel from out there cracks in areas where there is no reason to crack.
@@joshjablonicky171 Absolute bullshit.
I won’t second guess your diagnosis. But it has changed the way I do things. I just retired an old compressor with a patched tank thanks to your video. Thanks
*Seams are on the bottom for SAFETY... THINK ABOUT IT - if the seam was on top how much MORE shrapnel would the motor and compressor make?*
Right but the whole situation was caused *because* it was at the bottom, if it were at the top, it wouldnt have rusted nearly as bad at all
Plus the seam isn't directly at the bottom. There would have to be at least a 1/8'' of water sitting in the tank for it to be touching the seam.
Ehh, the seam is actually the thickest part of the tank. The seam didn't fail, it failed at the seam. At 3:10 you can actually see the seam is intact, the metal split next to the seam, probably because that's where the water sat. It wouldn't sit on the seam because it's higher than the bottom of the tank.
The reason it happened was due to bad maintenance and to have kept over its expected lifetime. The reson the seem is att the bottom is for safety reason when not handled right. You can see how extremely rusty it is on the inside and how extremely thin the metal had got at the failure point, just follow the edge from the left to right and you can see how extremely thin it is where it failed which is also exactly where all the condense water gather if not let out all the time which seemed to never had happened here. It should have been thrown out a long time ago it was just waiting for something to happen.
@@turbo2ltr when welding the metal around the seam can become weaker because of the heat. It is common for metal failure to occur right next to the seam because of this. Ask a professional welder for more detail, I am at best an amateur and would never weld a pressure tank myself.
Note that the factory weld was actually clocked towards the side of the tank so that water would have needed to accumulate to a fairly substantial level to reach it. That the feed line to the tank blew off its port is a good indicator that there was some blockage/restriction in the relief valve or its port leaving over pressurization as a very likely contributing factor in this failure.
The power of compressed air is very powerful and one of the worst examples happened at a commercial laundry that was over a city block in size where an entire city block was leveled by a boiler tank that got over pressurized after it ran dry and someone tried to refill the boiler manually before allowing it to cool down first. It was estimated that it only took one cup of water to develop enough pressure in a 2,000 gallon boiler to level the city block. The worker along with all the concrete around the boiler were turned to dust and vapor. This happened at least 60 to 70 if not 100 years ago at what I believe was the White Rose Laundry facility if I remember correctly and was quiet a common event, though not at this magnitude, before safety standards were put into place.
An automatic condensate drain unit the vents the bottom port on the tank every time the compressor cycles on and off to me as an industrial maintenance technician is almost a critical component for a horizontal compressor to ensure continuous condensate removal and best practice is to verify its operation every day the compressor is in use along with regular checking of the pressure relief valve by manually opening it under full set pressure to ensure that even though its free that it actually vents the tank and stays open to below pump cut in pressure so if it fails to vent or fails to stay open after you release it, then that is an indication that the relief valve is in need of replacement with one with an equal or lessor relief pressure. As the tank ages you should never change to a relief that vents at a higher pressure.
Coils between the compressor and the tank only better ensure that condensate ends up in the tank and does not migrate into your air system however a dog leg condensate trap with its own drain cock (preferably and auto-drain unit) after the cooling coils/device between the compressor head and the tank is a much better option as the bulk of the condensate should accumulate there and not inside the tank.
Though inconvenient a steel safety cage around a compressor to contain any explosive events is best practice however is no substitute for good condensate mitigation and regular safety checks. Dinging the tank with a pick though can be a double edged sword and end up causing a failure. Sounding the tank by lightly tapping the tank with a smooth faces hammer with no sharp edges on its face after the tank has been drained completely of all pressure is a better practice as is opening the largest port on the tank and inserting an inspection camera to verify the condition of the tank.
Welding a repair on a non-industrial tank is indeed an invitation for disaster unless your turning it into a non-pressurized piece of art or a barbecue.
A additional danger today is that some manufacturers, for user convenience, are putting the tank drain off to the side so that you have to tip the tank in order to drain it. I've seen some where this will leave about an inch of water in the bottom of the tank if you do not tip the tank so that the drain is facing straight down and hold it there until all condensate has been removed.
Indeed Be Safe.
Best!
Hmm. A coiled inlet pipe might well condense the moisture out. Guess what, it will then get blown straight into the tank! Don't work. You need a proper water vapour separator which drains into a bowl that can then be emptied.
A Coiled compressor Discharge line layed flat will allow water to drop out and run to tank True,,How ever if you run the discharge line to the bottom of tank and not the top,,can hear water level in receiver as fresh compressed air bubble's in the water,,where as if you put the Dryer filter between compressor and tank,,think impulse from compressor will change how it works,,after all the air is still hot and holding moisture,Need to cool air for moisture to drop out,,
Wonders has any body thought to paint in side of receiver,,be-fore use,,
I Know a lot of the bigger ones are ceramic lined to stop corrosion,Mind these are made from 20mm plate,,3/4 inch for the imp guys,and coated,with big inspection holes for longevity,and rectification after inspection,,
But A coat of the right paint will make all the difference,,
Now Some clever bloke is gunna ask how do ya paint the inside,,
remove all the fittings ,spread big sheet of plastic,,
Add Paint to tank and rotate,,never said it was gunna be easy,,
Tip out excess paint and let dry,,"BUT",,Must use the right paint,,as oil and other shit will cause paint to blister and cause more trouble than enough,,
Our compressor at work has a devise on the bottom of the tank connected to the drain that vents air out the bottom for like five seconds or so every few minutes....every thing else is just a gimmick. Same compressor has a built in drier, does almost nothing, still get moist air or the lines, same compressor has a coiled inlet line with aluminum cooling fins that raps around the cooling fan, again, does absolutely nothing, those last two things might be more useful in a lower demand scenario, but this compressor services both the paint booth and a cnc plasma table, both applications still require inline water separators and drop lines to trap water
He welded the bung
Also putting an inline water separator into the hot discharge line will fail due to the heat breaking down any plastic or rubber parts in it.
You got very lucky, it might be worth seeing what the design life of a home pressure vessel actually is, and if you exceeded it. I say this because I was astonished at how short the design life of some d i y tools actually is.
I want to thank you for posting this video. I've always been a little leery about old air compressors and I have an older one than that. Because of this video I intend to use a camera to inspect both my 20 and 60 Gallon tank and am considering placing the one in use outside when I intend to pump them up. In my opinion both your videos are a must watch for all compressor owners. I always wondered why large compressors at shops were outside in a chain link fenced area instead of the shop. On my tanks when not in use I always leave the drain open.
Drain bung had welds around it, so tank had shown signs of severe rust damage, it was 'patched up' instead of being disposed of as it should have been. Who ever welded that tank up and thought it was safe to continue using even though it had already rusted though in at least one spot was and idiot.
3:05 Yep, the tank looks like it was welded. Any leaks in a tank are a sign that it has failed and needs replaced and not welded. There are a few vids popping up on YT showing exploded tanks that have been rewelded however few posting the vids realize that was a warning sign to replace the tank.
I saw that too.... never Weld on a compressor tank
Also I had a pressure relief shut off go bad
I have a welded compressor from 1986, drained once a month maybe. I intend to keep it for another 20 years
@@thatguycarmine1 you can do it but the weld better be perfect most humans can’t weld perfect
We had a used compressor (homemade from a farm) that we would regularly use to work on our cars . During the weekend we might have as many as 10 friends hanging in out all day. This air compressor exploded during the initial fill , as the contacts froze and the pressure relief valve was not working. My brother had gone in the house while it was filling. It blew out an entire wall with shrapnel everywhere. The fire department said they never saw anything like it. No one was hurt. I suggest that you NEVER purchase a used unit and do a routine safety check on everything.
Never build a pressure vessel yourself
@@phitsf5475 why not? model engineers do it all the time!
Adding coiled tubing will lower compressed air temp into tank, but will not remove moisture. Moisture content in the atmosphere is what you will find entering the tank.
Exactly! The moisture collects in the coils and still drains to the tank.
Yessir you are right! This is just air, not an "Ideal Gas" PV=nRT kind of thing. Have to remove moisture through an atmospheric condenser to get the water out first then run into the compressor.
Put an appendix looking Y branch at the bottom with a faucet valve to manually drain it. 2 buckets for chiller, top one is full of water, bottom one just as raiser. You can lift off the water bath, drain. Or use ice and easily swap it out. It'll heat up 5 gallons of water fairly quick. The tank stays cold. Enjoy your adventures down the plumbing aisle.
@@canuckfixit7722 the ideal gas law has nothing to do with dewpoint. The T function in that equation only deals with temperature's effect on expansion and contraction (V) or the effect on (P). However, you are correct, cooling it makes it cold humid air below its dewpoint at the higher pressure instead of warm humid air above its dew point. As a matter of fact, cooling it without drying it makes the problem worse.
@@stanflahaut1893 That is why I said "*not* an ideal gas kind of thing".
Thank you for this video! I used to have an automatic drain on my vertical tank but it quit working after a while so I installed a manual ball valve into the drain line and I make it a point to manually open the drain before I turn on the compressor and at the end of the day when I turn off the compressor and I never leave the power on to the unit when I'm not present and working. This is incredible what you experienced and I am thankful you are ok. Thank you again for sharing this.
I only run vertical compressors and the drain is always slightly cracked open. I loose air, but not enough to make a difference. Self draining and if i don't hear air leaking, leads to an inspection. I also check the pressure release. I pull it under pressure and let it bleed until it resets. I've had debris come out of the the pressure release valve, so i check frequently to make sure the valve doesn't freeze up. On another note, don't neglect your water heater safety valve. Years ago a water heater blew up in our area, shot it through the roof of the building and it landed in the street. Glad to see your focus on safety.
As an added bonus when you move the compressor outside it gets MUCH quieter inside
😲
China
Thanks for this eye opening video. I'm not a professional, I'm just a homeowner with tools and just like you said "I'm not too old to learn" Thanks.
Thank you for sharing this. I recently built a small shop. I had an area under a bench set up for my compressor. I will now be adding a small room outside to put the compressor in instead.
Thank you for posting this video. I never thought an air compressor could explode with that much force. I will definitely drain the tank and check for the number of cycles on my unit!
Never hit a pressure vessel with a pick!!! Internal inspect with a torch and camera. Hydraulic pressure test every five years. Drain every day.
No one is getting their home air compressor inspected every five years. Drain it every so often and it will outlast you.
@@gfpd2722 If you check your insurance it is your legal duty to ensure that a pressure vessel is fit for purpose, that means an inspection.
@@union310 Just asking but do you really think homeowners are getting their air compressors checked?
@@gfpd2722 I just took one very much like this (36 years old) out of service and built an out building for a much larger 80 gallon high flow upright which I pipe air underground through copper line back to the shop. I got tired of the noise and i didn't have the air capacity I needed. You are correct, my old horizontal 25-30 gallon cylinder has never been hydro tested or inspected. And, I doubt I drained it as much as I should have in recent years. I'm tempted to cut an inspection hole in the cylinder to take a look at it. I was going to give it away but having seen this, I'm going to salvage the motor off of it and recycle the rest. A home owner seeking a hydrostatic test every 5 years is pie in the sky.... it will never happen.
@@usethenoodle I'd strongly suggest cutting a hole in the tank and disable the head to make it unusable. I know someone that was given an old compressor and was hurt by it when the tank failed. He sued the guy that gave it to him and won. Old compressors become time bombs.
I have an upright Craftsman in my garage I keep charged. I’m going out right now to drain the pressure! Thank you fir this video and sharing your experience!!! Stay safe.
Look, I’m no expert but the steel in that receiver looks and sounds very thin. The fact that it let go along the weld seam is suspicious to me as well. I’m thinking that the problem isn’t rust but metal fatigue because the metal used to make the tank is so thin every time the compressor kicks in the tank expands slightly from the pressure and then contracts as you use the air. This cycle would be repeated thousands of times over ten years. If this is the case then I would fully expect it to fail at the weld seam as that is where the greatest amount of flexing would be because you have the thin metal of the tank meeting the thick metal of the weld. This would then act as a hinge point and although it’s only a tiny amount of movement given enough cycles that is where I would expect it to fracture. As you pointed out, if a pin hole developed in the tank from rust then, like you, I would expect it to just leak. Most aerosol cans run at 70 - 100 psi and I have punctured plenty of those and never had one explode. By the way, the cans have a warning not to puncture them even when empty because most of them use butane or propane as the propellant so one spark even when empty and it’s all over rover. There’s a good reason they use those gasses but that’s another story. It might be worth your while running a magnifying glass over the point of failure to see if there are any signs of a rust hole but I’ll be surprised if you find one. I think once the seam had failed the sudden release of air was big enough to rip the tank apart like a balloon popping where as when you get a pinhole there is enough metal around the hole to stop the rest of the tank from tearing open. I wouldn’t mind betting that it’s a cheap Chinese compressor. Do yourself a favour and buy a decent quality American made unit. I have two Australian made compressors in my workshop, a triple cylinder I use for sand blasting and a twin cylinder I use for everything else. Both compressors have tanks that have a 50mm plug at each end that can be removed to allow cleaning and inspection of the tank. I service them once a year and each time I take the compressor outside, remove the plugs and clean out the tanks. I even have a wire brush on a stick so I can clean the gunk off the bottom of the tank and eye ball the inside. Something to watch out for is that I have noticed some of the quality brand names here are now using Chinese compressor pumps and electric motors and maybe even tanks for all I know and assembling them here and whacking “made in Australia” stickers on them. I hope what I have said makes sense and I am happy to be proved wrong so please let me know what you find. All the best and stay safe. Cheers Stuart 🇦🇺
You definitely know what you are talking about and I agree. Too much cheap and dangerous crap is being dumped on us. China is calling the shots now.
@@charlessmith833 Hey Charles, you are so right. I avoid buying Chinese as much as I can, even though it means digging deeper into my pocket sometimes it my little protest. Cheers Stuart 🇦🇺
Hi Stuart,
Just wondering, is your compressor a Clisby?
Regards Mark.
@@chisza777 Hi Mark, I have two compressors running together but off different circuits for sandblasting and both are Com-Pac units made in Brisbane and running Clisby pumps. I also have my original workshop compressor, a Peerless made in Adelaide. Why do you ask? Cheers Stuart.
Great comment!! 👏👏👏
Ty for this vid good sir. After all the years of messing with them growing up in a junkyard u got me counting my lucky stars
Thank you for posting this.. I replaced a similar compressor. I was afraid it would fail. I then drilled holes through the compressor head and cut a hole in the tank. This was to prevent someone else from salvaging it. I could then see inside. The entire bottom was heavily rusted. Draining doesn't prevent corrosion. It just keeps the condensation out of your tools. If you live in a humid area, your tank will fail sooner. They hydro (water under pressure) test air compressor tanks for rating them for this reason. Water will dissipate the pressure in the event of a leak very quickly; compressed air releases energy (pressure) slowly. Hydro testing is MUCH safer.
Hydrostatic testing can result in VERY violent energy release. Hydrostatic testing of tanks and cylinders is usually undertaken in a containment vessel in case of violent release. Watch some videos of failed hydrostatic tests.
@@stanflahaut1893 when you fill the tank with water then plug in a 250 PSI air compressor (double its nominal max pressure), very little energy is actually stored in the tank - If it fails, it will simply leak.
Glad to hear you and the family did not get hurt.
Thank you, thank you!!! Greatly appreciate the time you took to post this.
Thank you for the info I had no idea👍
My compressor is a Montgomery Wards about 45 years old. Years ago I removed the safety valve and welded a plug in so I could get 275 out of it and get max performance from my impact and fill a car tire in under 30 seconds. But thanks to your video I've duck taped a blanket around the tank for safety. Thanks again!
hopefully that doesn't cause it to heat up the tank too much
Possibly the weld was a little porous from new and allowed rust to get into the seam and weaken it. As you said tanks usually get pin holes and just rust into uselessness. I have a huge commercial compressor where the tank rusted through I tried to patch it and found I was chasing the rust so it is junk. I picked up a vertical tank and found it was cracked where the compressor mounted on the top. I welded it BUT after seeing this it is going to get flattened and loaded in the scrap dumpster.
Thank you for taking the time to post this. I am in the logging business so hazards are a way of life however if I am tempted to take a short cut I remind myself that it will take less time to stop and do it safely than to even get to the emergency room.
My brother in law had a similar sized vertical compressor. They probably never or rarely used the drain TBH. The bottom with the water finally rusted out and let go. The tank was in the corner of their garage and shot off vertically like a rocket and blew completely through the garage roof and landed some distance from the garage. So a vertical tank is just as likely to let go as your horizontal one.
Sir, thank you for sharing this. This post may save a life in the future. I have several compressors and one is a Craftsman about the size of yours. This one I use for sandblasting and the cabinet is about six feet from the compressor. Well it won't be in the future. I'm getting it as far from me as I can. Something to point out is that the metal adjacent to any weld, which is referred to as the Heat Affected Zone (HAZ) undergoes a change in the grain structure as a result of the high heat. When a weld fails, it is generally in the HAZ if the weld is not stress relieved; known as post weld heat treatment. This would have been the manufacturer's fault had they skimped on this step.
these tanks can be pressure tested with a gauge and a pressure washer pump. typically tests should be minimum 1.5 x max working pressure. if it fails it fails. if it dosnt you can now be confident the tanks not going to rupture under normal pressure and they should be tested every x amount if years(idk the number). its called a hydrostatic pressure test iirc
These were really fascinating videos. Far too many people crap on safety precautions, and in many instances I'm one of them too, because you think, it's never going to happen to me. These videos have given me new appreciation for why those precautions exist in the first place. Thanks for sharing.
Funny how you never mentioned the additional welding that was clearly evident in the other video, also at about 7:43 the tank looks very thin with severe corrosion. Its great that you posted this video and the other, we all need reminding just how dangerous these things can be.
me and my father build cars in our garage, have an air compressor he bought new in the 80's. It is a vertical unit, but now I will definitely get on board to build a little closet outside the garage like he's been going on about for years.
Glad you and your son are okay, I'd be lost without my old man
Get some cold air inside of that little closet you're building for the compressor too
Make sure your compressor has a "code" tank, it will have a stamp welded on it. That receiver looks awfully thin!
Glad no one was hurt! That was basically a bomb going off. Must have sounded like a depth charge.
Thank you for all this information. I'm so glad no one was hurt.
Mate im putting my compressor in it's own little shed out the back thank you so much for sharing
That is more like bad piston rings and compressed oil mist. As back pressure increases, oil mist in piston begins to diesel, flame runs back along the line into compressor tank and ignites the oil vapors inside there, like a giant spud gun without barrel. Tank explodes because no way to get the pressure out.
Btw, seems to happen most often with cheap single stage compressors, high compression ratio makes piston blowby and dieseling much more likely.
Failure at the seam is only because it's the weakest part on the tank, not because it was compromised. Look at the yielded areas next to the seam, that wouldn't happen because of rust, only a short, massive rise in pressure does that. Seam is only what gave up eventually.
Fascinating theory. Would love to see the Mythbusters take this one on.
Your message is a good one - safety is important.
thanks for the heads up, this changing how i work with air compressors.
Thank you for posting this. You could of easily just bought a new one and none of us would have learned how dangerous these can be.
I just saw this and had to check for my self . Never even knew you had to drain the water in the tank thank you for that advise 👍🏽
I went to one industrial site, where the vertical 2,000 gal tank, was almost 1/2 way FULL of water - It had an automatic drain that had become plugged with rust particles, so it would not drain at all. The company discovered this when the compressor stopped, an a fountain of water gushed out of it (piping to the tank, entered near the bottom).
"Pressure Kills" - I remember my brother telling me this when he took me to my first oil well fracking job. He also said "Complacency kills" and said that we would likely see a lot of people casually walking around but that we should be mindful and speak up when ANYTHING looks or sounds odd because that's often how people get killed, they underestimate the danger they're in.
I have watched both your compressor videos , thanks for sharing , I had never seen this before and have shared to friends with compressors. Glad no one was hurt , you were very lucky as it was easily able to kill, like you say imagine it under a bench covered in tools such as files etc and that happening. Thanks for posting a very informative video for everyone's safety benefit 👍
Thanks for sharing a hard lesson to everyone. Glad you and yours okay.
The manual lift on a safety valve is to check that it's not seized. The valve needs to be removed and tested against a calibrated pressure gauge to see if it lifts at the set pressure. Inspection of pressure vessels, requires a thorough visual inspection inside and out together with an ultrasonic thickness test at various points of the vessel.
Good Video , Thanks for the Tip 👍 certainly made me a heck of alot more aware of a potential hazard, Kudos 👍
This is a good demonstration why commercial units have line dryers, aftercoolers, and automatic drains. My commercial Chicago Pneumatic compressor vents all water out of the tank every hour. You can purchase these automatic bleeders for about $100 and set them from 20min to a few hours, usually.
I have never seen a dryer on the input of a compressor. only on the output. where would a person even get an input dryer?
Wow! I'm glad you are ok! I've been In shops for 40+ years and never seen this. We don't think about, being older folks, how much cheaper things are made. Think 1960s Chevy compared to 2000s Chevy. As older folk we have been made too comfortable with things manufactured today.
On that note I have an 80 gallon upright compressor against the wall in my garage. It's going to get its own little house on the outside.
Be safe and have fun!
Terry from South Carolina
One other safety note on air compressors is the lines and fittings should also be to standard. The hose fittings can come off and whiz like a bullet around the shop if not secured with the proper clamps.
Back in the day, the tanks were made of thicker sheet metal and failure would be in the form of a pinhole that would leak and render the tank for scrap. Thanks for sharing and take care folks.
After watching this video, I have to get rid of my air compressor and air tools aswell. Thank you for sharing safety comes first.
On one thing you were very wrong, the hot air IS NOT the moist air, just the opposite. Relative humidity of air actually drops and air gets ''dryer'' as it gets hotter and cooling it down will just increase it's relative humidity and consequentially as it gets above 100% condensation will start to form and pool on the bottom. The thing is when air gets compressed it's relative humidity also rises up and that is what causes condensation of water in compressor tank. Lets say it like this for example, you have air, it gets drawn into the compressor, gets compressed and exits as HOT air with maybe even LOWER relative humidity than before BUT as it cools down in the tank that's when humidity rises and condensation forms. Therefore whether you cool it down quicker with additional pipe length before tank OR in the tank alone doesn't make any difference at all.
Well one thing I can say is adding that extra tubing will let the air cool down and condensate leaving behind the moisture. Just like a cold glass of water sweating. But you would have to drain the tube out. In this case you would rather water in the tube then the tank because the tank can blow up as you have seen in the video. This will not eliminate the problem but have the tank last longer. Thanks for the comment and hope you enjoyed!
Air's ability to hold moisture is relative to it's temperature, that why it's called relative humidity, it's a measure of how much water vapor the air can hold based on how much water vapor is currently in the air, relative to it's temperature. If you increase the air's temperature, you increase the ability of that air to hold more moisture, hence you lower it's relative humidity, but the amount of water vapor (all things equal) is the same. The dew point is a better indicator of how much moisture is in the air. The dew point temperature is the temperature at which the air is totally saturated and can no longer hold moisture. The higher the dew point temperature, the more water vapor in the air. As you compress air, you increase it's temperature and it increases it's ability to hold more water vapor, as the compressor runs, you add more water vapor that comes from the ambient air. Because the compressed air is warmer, it can hold that additional water vapor and the dew point increases. But as the compressed air inside the tank cools, it reaches it's dew point temperature, and condensation forms inside the tank. Coiling the feed line in the tank causes the condensation to happen in the line and not in the tank, the water in the coiled line will be pushed into the tank. Compressors with coiled feed lines still need to be drained.
@Do One the proper way to remove condensation from the air as its being compressed is with an air dryer.
@@3generation_racing658 water is literally squeezed out of the air being compressed,no way around it all you can do is drain it out after the fact. They sell electric timed gizmos you hook up to your drain and let the water out at an adjustable interval,just the thing to minimize rust in the tank. On a side note like others have said that tank is super thin looks to be about 060 thick or1.5 mm should be more an eighth inch thick. I’m sure you’ll replace it with a higher quality unit preferably made in USA.
@@3generation_racing658 The condensate will just get pushed along the tube and into the tank. It won't just sit in the tube. And by the way, rolling a coil of tubing it probably not a good idea. That length of tube is kept short and simple for a reason. The only way to dry the air is to use a pressure swing adsorption column and molecular sieve to pull the water out. They are usually set up in tandem so one column is drying the air and the other is either regenerating or waiting its turn. When you take ambient air, even at a relatively comfortable 50% relative humidity and compress it from 15 psia (absolute pressure) to 115 psia (absolute, or 100 psig), you squeeze the volume down by a factor of 7.66. Since the humidity of the air is based on how much mass of water there is per unit volume, you now have air at almost 385% relative humidity once that air cools to room temperature. You can count on getting water in the tank.
Thanks so much. If I ever buy another compressor, I will most certainly check to see where the seam is. That should not have happened, but it did. You are extremely lucky or blessed. It might be a good idea to bring this up to every seller of compressors in the world.
I think there is a mistake in your understanding about moisture. Moisture is not "produced" during compression in the cylinder. The absolut amount of water is still constant. It starts to condensate in the tank, most of it, when you use the air, therefore the tank is cooling down according to a decrease in temperature of the air (because of expansion). Therefore the cooling of the compressed air before entering the tank will not help to prevent the moisture!
In that case it will condense in the pipe. and you could drain it at that point, probably with a conventional moist trap.
@@oddballdynamics.9658 That is called condensation. en.wikipedia.org/wiki/Vapour_pressure_of_water
@@matekochkoch: lol. My mistake. 👍
Well done video. Good follow up explanation. Good point. NEVER WELD AN OLD COMPRESSOR TANK!
money saved vs family lost...hell of a thing to live with after...
Ur first video convinced me to stop fixing mine thank you for opening my eyes
"If you suspect your tank is weak..."
Spot welds the rust holes.
No you are not suposed to weld the pressure tank
Defiantly weld it
@@matocro8745 Sure you can. They say not to, but it's all just a scam...like ink cartridges for printers.
@@terrismith9095 the inc carterages i agree but welding the tank weakens the metal becouse of the heat and sure it will hold but for how long and do you want to risk jour life for a replacment tank?
Great warning I will be passing on to all my techs tomorrow. I totally agree with the idea of completely draining the tank at end of shift. Hard to believe that one was only 10 years old. I also appreciate the fact you weren't pointing fingers at the manufacturer. Wishing you all the success moving forward and thank you. Liked and subscribed.
You only need to drain the water out not all the air, otherwise you are just using up life cycles!
Thanks.
I have worked with compressors, cylinders of compressed gases and with large dewars of compressed liquified gasses. Only in one workplace did they have the units outside the work area and outside of the building. Even university administrators and safety officers did not change and move the compressed gasses or compressors outside the building.
After seeing the damage your compressor did, I suspect that such a compressor explosion would cost in excess of $50,000, perhaps $100,000, maybe more in the laboratories where I worked. Scientific instrumentation is expensive.
Thanks again for your videos.
It is very nice of you to share you experience. I was about to purchase an used air compressor and your video reminded me that the tank on an air compressor is a pressure vessel. Pressure vessels can be very dangerous when not used or maintained properly. First and foremost there it proper use and maintenance. Manufacturers recommend draining after every use, and checking the operation of the PRV often.
I am not sure how high of a pressure setting was being used, but it is good to keep is only as high as needed. I have a personal unit that I never let get pass 90 psi, even thought he unit is rated at 175 psi. Still 90 psi is high enough that it can kill someone. I will be more careful when using my compressor moving forward.
Finally, in your first video you mentioned ear drums... Yes. It is good idea to use hearing protection when working with air compressors and pneumatic tools. I had a friend who die when a tire with 90 psi blew next to him. What killed him was the sound which blew his drums.
Be safe out there.
you don't drain it regularly. you drain after using it every day. you want to avoid the air inside to condensate. also the drain valve should be left open and close it only when ready to use the compressor again.
I was taught years ago to leave the drain petcock slightly open at ALL times, even while compressor is running.
It only needs be be a small “leak” to prevent condensation from remaining in the tank. This came to me from a former major brand race car engineer.
@@bobscott1315 can you explain? My english not good. I have a small 2 gallon was given for gift
@@scylla_39 Sure! All compressor tanks (as far as I know anyway) have a valve on the tank. Usually this valve is placed at the very bottom of the tank. This valve is used to drain ANY accumulated moisture in the tank. Most people will close this valve. They close it to keep the compressor from cycling while it is being used. Wean the valve is closed moisture accumulates inside the tank ABOVE the valve. You are to then drain the tank by opening the valve when the compressor is turned off to drain any moisture. Many people will then close the valve until the next time they use the compressor and need to drain it again.
What I was taught is that drain valve should ALWAYS stay slightly open. You should hear a small hissing sound whenever the compressor is on. You may not be able to hear it if the compressor motor is running.
As long as that valve stays open, and you hear the hissing sound, NO moisture can accumulate as it is immediately blown out the valve, thus preventing (or at least reducing the amount of) corrosion (rust if steel).
Check in the manual for the compressor, it should tell (and maybe show) where the drain valve is located.
PLEASE NOTE: this ONLY works where the compressor that is being used has the valve at the VERRY BOTTOM of the tank when it is running. MAKE SURE that the compressor is in the proper position. If it is NOT properly positioned there is an almost certainty that the MOTOR will FAIL as it will not be getting proper lubrication.
(If is a vertical compressor use it vertically. If it horizontal us horizontally. )
@@bobscott1315 Sounds like a great idea.
Leave drain plug slightly open during use and I suppose when not in use.
Then you may not need to open drain fully at all.
@@bobscott1315 What was his thinking on that? Is there a danger of the condensation becoming heated enough to have like steam power or pressure added above and beyond the tank cut off pressure?
I was just looking at a temp/steam pressure chart and it would take a temperature of 338 degrees F to build 100 PSI of steam pressure in a boiler.
Thanks for sharing. Glad you're ok.And coming time to check all things in my compressor even is used only 2 years. For that cracked tank need more than 25bar even with rust from years of use.thanks
Hi,thanks for a very interesting video,before retirement I worked in Garage Equipment and all receivers/pressure vessels were inspected every 24 months.This Inspection consisted of removing pressure gauge and pressure relief valve and testing them hydraulically using a water pump.The vessel was opened up at the end and inspected visually.Readings were then taken 4 readings from the top,4 readings from the bottom and 4 from each side using an ultrasonic tester.In my experience the older vessels were built to last normally 1/4 thick and apart from slight pitting internally would last up to 40 years.Unfortunatly more modern units typically manufacturerd in Italy or China start life at about 3mm and you are only allowed 0-50mm deterioration.I would be interested to know where your air tank was manufactured.I’m in the UK buy the way
Im in the uk also, and am an examiner of pressure systems through the British compressed air society (BCAS), also a member of the institute of mechanical engineers.
I agree with what you have said, especially about where the receiver was made. In the states they build to asme 8, these are not legal in the uk or eu as the standard is not deemed safe. Anything made in china with a CE marking may not actually mean it’s eu or uk legal as this mark also stands for Chinese export, be cautious.
The mention in the video saying the relief valve was ok is bs. Pulling the releasing gear doesn’t prove it’s reliving at the correct set pressure, only a test with a calibrated gauge will tell you this! And do not pull the easing gear before the test as this could actually prove it safe whereas before you did this it may have been stuck ( your fingers / eyes etc are not calibrated!).
If this compressor went over pressure to blow, would mean that the prv (pressure relief valve/ safety valve) and the pressure switch were both faulty, plausible but I would be falling on the side of poor maintenance , receiver construction and inadequate design for safety.
This is a great video, at my shop I was afraid something like this could happen that's when I bought a brand new 1,000 gallon propane tank and I use a V-4 air compressor also I installed and car ac condenser and a dryer and after every shift the tanks is opened up and drain any water then in the mourning they run it for 10 minutes before closing the drain valve.
Cooling the air does not remove the moisture. The coil only serves to reduce temperature and condense the moisture. How much metal eroded? What's the thickness loss from rust versus the clean steel. How do you know the pressure release works? All you showed was the valve moved. You didn't prove the passage was clear.
".. is WerKing jest FINE" .. Lol.
I was thinking the same thing. There will always be moisture in the air, unless you have a drier installed.
Dan Wood these are good questions. I’m sad nobody seems to have noticed. They’re the questions an engineer would’ve asked.
Thanks you for sharing your experiences with us. It is very important to us.
I had o furniture factory for 30 years I have hear of this happening. The Gov. regulations hear in Brazil obligate that you have to have the tank checked pireadactley with a hydrostatic check, first on installation, second 5 years, third 7 year, fourth 9 years, then every year and discard at 20 years. A log book has to be kept and updated every intervention that is made to the compressor unit. A hydrostatic test is made by taking off and capping all access to the tank but one. On this one access point is connected a hand pump and with gage and pumped to 2 X the nominal working pressure for 1 hour.
WOW,good video.Thank you for posting this as a public service. I have the same compressor.BUT mine is copper brownish looking and it has the craft**m lable with a cert tag welded on it. I remember when i bought it in 1980? they had 2 versions.The red like yours and the brown one with the cert.Lots of times back them s**rs had two versions of tools etc.the red stuff was the cheaper ,then they had craft**M brand with like a lifetime guarantee on tools and battery's and stuff.REGARDLESS of this ANYONE that has an air tank NEEDS to be aware of the dangers of maintenance and regular inspection.JUST like the water hoses on your car,THEY wear out FROM THE INSIDE,making it much harder to see a failure coming.I'M going to send a link to my friend in INDIA,he repairs trucks there and they PATCH EVERYTHING.MAKES me queasy just thinking about it.GREAT VIDEO,thanks again.THIS is going to save a life.
Dude, that's scary! Thanks for sharing this experience. Glad you guys are ok!
I hope you found this somewhat Informational! I appreciate your kindness and thank you for the comment!
@@3generation_racing658 most definitely informative. I have an old compressor that I'm throwing out!
@@3generation_racing658 What make was it?
THANK YOU for showing us what happened! This should be a cautionary tale for anyone with a compressor.
I use a auto drain valve in the one I have at work. It has a timer that opens the solenoid valve on it to drain the water.
thank you for the PSA. eye opening. i have heard a million times a pressure vessel is dangerous but i never thought a home gamer unit could do this much . crazy!!!
I have a tank in my garage that is pressurized all the time and I’m going right now to drain the tank. What a wake up call. Glade you are alright man and I’m going back to the previous video and edit my comment
Do leave it pressurized all the time. Cycling is bad.
The main thing is to drain the water out regularly.
The petcock they come with are junk, I replaced the petcock on mine with a ball valve, it has a much bigger opening.
I also piped the drain to the side so it's easy to see and get at, that way you do it more often.
Mine’s just ten years old, domestic, not much work done. Frequently drained, tank slightly inclined toward drain. Opened up inspection bush. Plenty of wet rust, so draining is far from the solution. No second guessing this... replace now!
Good pointers thanks, Automatic drain valve and manual maintenance are both of big help
The intake air would need to be dried. Once it's at the output condensing it is meaningless since the water still just goes right into the tank
Yes Micheal, a coil to cool the air between compressor and tank will just condense the water in the coil and it will just dribble into the tank. Ya gotta dry the air before it is drawn into the compressor, and that isn't easy or cheap.
@@tommo033 I'd suggest draining regularly, periodically fogging and the occasional bore scope inspection for half meaningful piece of mind.
Your pressure reg failed. Yes, you can manually pull the release BUT it doesn't take much for it to stick. I've seen HVHP compressors fail. You were lucky and isolating your compressor from your workspace is a great idea
I have never seen this tank failure before. Thanks for putting up these videos about your experience. I will never operate one inside my garage again.
Looks like very thin metal before it started rusting.
Made with the finest Chinesium.
@@kencress1267 In his last video he says this is a husky made in the U.S.A.
@@explosivemallard8038 you mean just like how cars start rusting just after a couple of years.
@@kencress1267 I don’t understand your comment. I thought we were talking about this man’s air compressor.
@@explosivemallard8038 Sorry to say that Husky is crap. I had a pressure washer that did not last a year with little use.
Thank god no one got hurt, count your blessings, this was just a warning to you and all of us now that you've posted it! For that I thank you..I'm now going to order one of those £8 inspection cameras that looks like a Dr's endoscope and have a good look around inside my tank!
They make racing blankets for transmissions,and intake manifolds with blowers.I wonder if any of this could be used on a compressor to contain any metal shrapnel from an explosion?Thanks for sharing this danger.
The thing took off like a rocket. It just would’ve been a rocket wrapped in a blanket
The blankets are not ideal. Scatter shields are better. The blanket prevents your death. A scatter shield will protect you from death or injury.
I was a compressor engineer for many years and have never seen anything like it, yes i've seen them crack and release the pressure, this must have gone way over pressure, i've opened hundreds of receivers for insurance inspection and they all have rust, a dent in the receiver will automatically cause it to fail but very rarely do the fail because of the rust, an auto drain fitted to the receiver is best option electronical solenoid types that you set to blow off for a few seconds every couple of hours are cheap.
Damn that’s not good. Glad everyone is safe. If you still have the dipstick give ya few bucks for it
Thank you for sharing! Really! Never would have thought of that happening. These tanks should have an expiration date, similar to propane tanks if you think of it.
Did ya find the black box?
No but the passports were ironically in perfect condition 🤷♂️
Most people have zero idea how much force they are dealing with in an air compressor. As a professional in the pressure vessel industry, I've often had to do the math for people. That tank has roughly a 17.5 square foot area using the numbers I found on Husky's website. Multiply that by 144 (square inches in a square foot) and then multiply that number by 100 pounds per square inch, and you get 252,000 pounds of force, or 126 TONS of force on the inside of that tank.
That's why when it blew up it did so much damage. Looking at it from my perspective, knowing the forces involved, it actually wasn't all that much damage. The owner got off VERY lucky losing a garage door track, some speakers, and all the glass in the garage. We get very complacent around pressure vessels because we're used to them. It's the same complacency that we get while we're tooling down the highway at 70 MPH. It feels normal, so we don't think about it. But put the car sideways in the rain and suddenly we remember that we're moving VERY quickly.
Realistically there's nothing you can do to prevent this except to look carefully at your tank. I don't recommend beating on it with a hammer, but tapping gently might reveal cracks. Just remember that you're trying to FIND damage, not CAUSE damage. Drain your tank regularly, just as the owner says. And if you're not perfectly happy with the state of your compressor, junk it and buy a new one. As the owner says, if his son had gotten up early to work with him, he'd have been standing right next to it when it blew. Compressors are expensive, but nothing compared to losing a son.
The owner is ABSOLUTELY correct that you should NEVER weld a tank. If you do not possess the required pressure vessel welding certifications, you're just going to make the tank weaker. DO NOT WELD PRESSURE VESSELS!!! I can't stress this enough. It's actually illegal as well as weapons grade stupid.
Would this tank have been heat treated after fabrication?
Tanks pretty much have a limited life, and emptying them only helps so much. Wet steel rusts faster than steel that is entirely underwater, so it's always gonna rust.
Thanks for posting! I've got a 25yr old compressor about the same size that recently started springing some pinholes in the bottom, it looks like I need to replace it sooner than later! Such a shame too because the rest of it still works perfectly fine.
You can buy tanks, if your motor and compressor are still ok.
Our guy was asking for this to happen. 3:05 The tank looks like it was rewelded around the drain fitting. Any leaks in a tank are a sign that it has failed and needs replaced and not welded. There are a few vids popping up on YT showing exploded tanks that have been rewelded however few posting the vids realize that was a warning sign to replace the tank.
Thanks. I've got an old compressor that has been siting out in the shed for about 20 years that I'm always thinking about digging out an firing up. Not any more.
When you get your new one treat it with boiled linseed oil inside leave it to dry and it will help stop the corrosion getting into the tank so bad!
Well you can check the expiration date that's stamped into the side of the tank. If it's expired by more than 5 years then it's kinda not a freak accident. Standard lifespan for an air tank is 10-15 years. All legitimately manufactured and sold air tanks have an expiration date.
Exactly. You are correct. I had my tanks inspected by the manufacturer after and re certified.
The skin of that air receiver looks very thin. I reckon that compressor was a cheapy. I have worked with and built a number of air compressors and am pretty sure that was your problem. Just the first bit of rust along that seam and it was ready to explode. Putting the seam to the top presents problems of its own. You will see decent manufacturers put the seam at the 5 o'clock or 7 o'clock position. Be glad no-one got injured.
Yes we think the combination of rust and the seem on the bottom where water will collect was the main factor to the blow up. We also think the tank was thin too, which didn’t help. Thanks for commenting and be safe!
Tanks have been getting thinner and thinner steel wise.
The postal service in the UK bought a truck load of this type of compressor so they could pump up the van tires.
After there first safety inspection the lot got scrapped. Tanks were that thin steel wise the insurance inspector condemned them. Made in China.
I have this identical compressor. It's a Husky from 1999. It was my dads and I inherited it about 6 years ago. I drain it all the time and I even take off the air filter and spray WD-40 into the intake every other month to keep rust from biulding up inside
Careful, wd40 spray is explosive, you probably don't want compressed explosive gas in a compressor tank. Spray it over a lighter and you'll see for yourself.
@@8180634 I've done it hundreds of times I tested my luck lol. I was worried about it Desiling in the compressor pistons. But never has so far.
@@trxtech3010 It only takes once to blow the whole tank up.
@@8180634 I'm sure i've put more then that into it.
Did that drain get welded (repaired) on the tank ? I can see not factory welds around that drain area.
3:05 Yep, the tank looks like it was welded. Any leaks in a tank are a sign that it has failed and needs replaced and not welded. There are a few vids popping up on YT showing exploded tanks that have been rewelded however few posting the vids realize that was a warning sign to replace the tank.
The rupture did not occur at the supposed repair, weld.
@@heydonray The rewelds are a sign that the entire tank floor is becoming weak and needs to be replaced.
@@heydonray I understand that. But it was a sign your tank should not have been fixed. Should’ve been retired than
@@bobroberts2371 Monday morning keyboard warrior quarterbacking.
I place my compressor outside due to the noise when in use, now I'm warned ⚠️ about the Hazzards. So awesome advice. 👌
Every time I look at my compressor I think "1000lb bomb" i just had my pressure switch fail and the new replacement I lowered the cut off pressure just in case! Real glad no one got hurt.
There should be a pop-off valve in the system as well. I run 180psi at my shop, that's a commercial grade compressor and 80 gallon tank though. Every few years a guy comes out to test it ultrasonically then issue me a new "permit to operate pressure vessel."
@@lironmtnranch4765 yes there is a safety valve in the system too 👍
Nice follow up....Thanks for the info !!!!!! Life Saving
I was thinking about the vertical versus horizontal thing, I'd think a vertical (or even one of those little "pancake" ones) would be less likely to explode like this from corrosion not due to the weld seam but because water would collect in a puddle in the bottom, a spot, rather than a line along the entire bottom. Regardless of where the weld seam is, if water creates a line of rust along the bottom that would create a seam that could blow. A small spot would blow out less catastrophically. That's my guess anyway, couldn't find anything written about this. As for the cooling loops in the line, that wouldn't help - it would condense water out of the air before getting to the tank rather than inside it, but water is still ending up in the tank.
Good warning. Perhaps I have been too cavalier as well. One of few actual examples I have seen of a catastrophic failure on a small unit with no external factors.
Adding all sorts of dings with a pick on a pressure vessel is a very bad idea.
I appreciate the comment. The correct way to do it would be to sonic test it but most people don’t have one. So another way would be to ding it. That way you know if the tank is compromised. Just make sure you drain all the air out! Thank you.
@@3generation_racing658 Best way is to hydraulic test it, to at least 1.5 times working pressure. It will find faults that sonic misses, and if it passes you can put it anywhere you like or stand right next to it without fear.
@@3generation_racing658 I have an Ultrasonic thickness tester, bought on Ebay for $85. I tested all my air tanks with it, and also hydro-statically tested them. And I'm still leery of the older ones even at 120 psi.
@@Titan604 Yep, hydro testing is the right answer.
@@3generation_racing658 What is the brand name for this compressor? It looks like a Craftsman paint job but no name on the tank that I could see. The tank appears to be very thin walled so no wonder it tore apart so much. I thank God that you and your son weren't hurt.
I live in the UK. I have worked in the air compressor industry on a USA air base in the UK. UK law require inspection of receivers for insurance. My job was to do these inspections. All fitting are removed from the receiver and it is then filled with water a pump is attached and a pressure of 1.5 times the max working pressure is pumped into the receiver. All welds and seams are taped with a hammer and inspected for leaks. If ok the working and test pressure are stamped on the receiver with the date. Large revisers have inspection plate which must be removed. Water dose not compress!