I have learned a lot from these lectures. The information is invaluable. Thank you. However, I prefer the old style lectures. Your voice is far too bland and robotic in these new videos. Not what I would call a "lecture.". In my opinion, you could get your point across way quicker and more effectively if you simply taught in a relaxed manner. Again, thanks for the videos. I've learned a lot and you can't just find this information anywhere on the web. Its very thin.
Hey Jim, I think in the internal pilot CB valve the clamping force will include the weight of the load just like in external CB valve . So in the internal pilot clamping force become 971.91-584.1 + 500 lbf = 887.8 lbf and in the external pilot valve it will stay 971.91 + 500 = 1471.9 lbf. Hence the overall result remains the same that in external CB valve you get increased clamping force due to no back pressure being present like in the internal CB valve . Correct me if im wrong .
An internally piloted CBV continually resists using back pressure even at the end of the stroke. Here's a link that summarizes the differences: hydraulicspneumatics.com/other-technologies/book-2-chapter-5-counterbalance-valve-circuits
hi jim, the vat full of roadkill, chicken feet, feathers and beaks compressed into nuggets and enjoyed by children threw me. i cant believe you said that in a monotone voice with a straight face. not far off what really goes into chicken nuggets i suspect. otherwise comprehensive and informative, excellent for the learner who has a good background in physics and maths, ive simply called these things pressure relieved piloted check valves. regards Richard
I have a fork lift that has the forks drifting down when NOT under load but under loads of about 1000 lbs of more the drift stops. I suspect something with the counterbalance valve but the symptom of drifting would normally be under load? Based on this video it is an internally piloted CB valve. Is it likely that either the pilot is blocked or the valve sticks? I have not seen anyone else describe drifting while unloaded but not when loaded. Thanks for any help
My operating pressure is 50 to 100 bar then Yuken make which counterbalance valve should I use. 1.HCG-06-A4-2180(Pressure range 18 to 35 kgf/cm2) 2.HCG-06-B4-2180(Pressure range 35-70 kgf/cm2) 3.HCG-06-C4-2180(Pressure range 70-140 kgf/cm2)
At 20:50 you fail to add in the 500 lb block when calculating the compressive force available in the Internal w/ 400 psi opposition. I think it should be 887.8 lbs vs. 1471.9 lbf instead of 387.8 vs. 1471.9 lbf.
@@bigbadtechThanks for reply sir, by "retraction", you meant retraction of cylinder or spring/spool present in the valve? Is Primary port towards valve arrow Head & Secondary port towards valve arrow tail ?
Hi great vids I'm spending a lot of time looking for a solution I am a commercial crab fisherman and I have a hydraulic trap hauler which is basically a winch. When a trap comes up out of the water and I put the directional control valve in the center position to stop it, it will slowly creep down and to stop it I have to put the directional control valve slightly in the "up" direction to counter act the drop. So when the trap is opened up and the crab drops and weight drops from the trap it starts to rise. I just need the hauler to hold the load when the directional control valve is centered. Any idea of a solution? Thanks
The creep is most likely leakage through the DCV center position. Check out the pilot to open check valve in the Hydraulic Schematics lecture at: ua-cam.com/video/NsgShyrcvqA/v-deo.html
Jim Pytel thanks for the reply I checked out the video It may take a dozen views to grasp it My creep has gone on since the system was brand knew. Is it likely the dcv would have that much leak from new? I've read that motors are prone to have creep. But find it hard to find the solution A counter balance valve seems like it might work
You can’t prevent the creep on any hydraulic motor using valves. You need to use a mechanical brake. Some systems can integrate either a hydraulic activated brake band on the winch drum or buy a hydraulic motor with integrated hydraulic brake system/s.
Hey there. I'm a little unclear about how the CBV maintains the back pressure to allow for controlled retraction. If I remember right you were saying that the pilot monitored pressure ensures that pressure on the input never drops below set value. I see how that would keep the valve open but I can't wrap my head around where the back pressure is coming from.
If the pressure drops below the set value the CBV returns to the deactivated closed state. Given no passage to tank, back pressure supports the descending load.
Yes some do. I think the ANSI standard use 90 degree. And the ISO 1219 standard has a 45 degree line going in towards the valve instead of away from it. Not that the standards are flawless or worth following in every detail but I think ISO 1219 is good for at least for the basic proportions of symbols and so on. The 45 degree line away from the valve is new to me.
A "pilot" signal is any low power signal that shifts a primary device. Pilot signals could be oil based, air based, or electrical. Check out the "piggy back" valve example in the directional control valves lecture at: ua-cam.com/video/QaagWlHbxr0/v-deo.html
Ring like rod end area equals area of the cap minus the area of the rod. Check out the hydraulics math lecture at: ua-cam.com/video/NDrauWbUmFw/v-deo.html
Very informative video, but the flat-voice narration makes it hard for the viewer to remain focused and distinguish the key points. No offence intended, I think that you should work on that and try to add some more vitality and pace variation to your storytelling.
No offense taken. I remember this one ... I was exhausted! My dad tricked me into residing his house and I knocked out maybe 5 lectures in one day. Never again! I'm not usually this robotic and you're not the first that noticed my deadpan delivery for this lecture. Ordinarily I'm a little more animated. Check out some of the newer material.
Really great videos man! Don't change a thing
I greatly appreciate these videos! Please keep up the good work!
Awesome explanation. Thank you
really helpful video and great explanation thanks
Well explained
I have learned a lot from these lectures. The information is invaluable. Thank you. However, I prefer the old style lectures. Your voice is far too bland and robotic in these new videos. Not what I would call a "lecture.". In my opinion, you could get your point across way quicker and more effectively if you simply taught in a relaxed manner.
Again, thanks for the videos. I've learned a lot and you can't just find this information anywhere on the web. Its very thin.
Jim's lecture is not without humor. Whatever the case it is quantity/quality mix hard to beat. Keep up the good work Jim Pytel.!
Hey Jim,
I think in the internal pilot CB valve the clamping force will include the weight of the load just like in external CB valve .
So in the internal pilot clamping force become 971.91-584.1 + 500 lbf = 887.8 lbf and in the external pilot valve it will stay 971.91 + 500 = 1471.9 lbf.
Hence the overall result remains the same that in external CB valve you get increased clamping force due to no back pressure being present like in the internal CB valve . Correct me if im wrong .
An internally piloted CBV continually resists using back pressure even at the end of the stroke. Here's a link that summarizes the differences: hydraulicspneumatics.com/other-technologies/book-2-chapter-5-counterbalance-valve-circuits
hi jim, the vat full of roadkill, chicken feet, feathers and beaks compressed into nuggets and enjoyed by children threw me. i cant believe you said that in a monotone voice with a straight face. not far off what really goes into chicken nuggets i suspect. otherwise comprehensive and informative, excellent for the learner who has a good background in physics and maths, ive simply called these things pressure relieved piloted check valves. regards Richard
amazing
bloody good, thank you
well done!
I would like to thank you for your efforts, could you please share information a about the instrumentation?
Stay in touch, instrumentation on the way.
@@bigbadtech yes , I am following you since a years, you are great .
will you please solve the complicated hydraulic diagrams. I mean please make a video hydraulic flow diagram
I have a fork lift that has the forks drifting down when NOT under load but under loads of about 1000 lbs of more the drift stops. I suspect something with the counterbalance valve but the symptom of drifting would normally be under load? Based on this video it is an internally piloted CB valve. Is it likely that either the pilot is blocked or the valve sticks? I have not seen anyone else describe drifting while unloaded but not when loaded. Thanks for any help
Hard saying from here but it might even be a faulty check valve bypass that is leaking.
Thanks
Thank you sir!
My operating pressure is 50 to 100 bar then Yuken make which counterbalance valve should I use.
1.HCG-06-A4-2180(Pressure range 18 to 35 kgf/cm2)
2.HCG-06-B4-2180(Pressure range 35-70 kgf/cm2)
3.HCG-06-C4-2180(Pressure range 70-140 kgf/cm2)
Great video! Did the kids like the nuggets?
Come here from SV Seeker ❤
You try to reduce the speed kiitie but its not clear ...but the content is valuble .
At 20:50 you fail to add in the 500 lb block when calculating the compressive force available in the Internal w/ 400 psi opposition. I think it should be 887.8 lbs vs. 1471.9 lbf instead of 387.8 vs. 1471.9 lbf.
Sir, what did you say at 7:38-39 ??
"during the act of retraction"
@@bigbadtechThanks for reply sir, by "retraction", you meant retraction of cylinder or spring/spool present in the valve?
Is Primary port towards valve arrow Head & Secondary port towards valve arrow tail ?
Hello have a question should the filter on a hydraulic system be before the pump or before returning to the tank ?
All you ever wanted to know about filters and more: ua-cam.com/video/0hJB_HXGsiI/v-deo.html
thanks jimmy for your help. have a good night
Hi great vids
I'm spending a lot of time looking for a solution
I am a commercial crab fisherman and I have a hydraulic trap hauler which is basically a winch. When a trap comes up out of the water and I put the directional control valve in the center position to stop it, it will slowly creep down and to stop it I have to put the directional control valve slightly in the "up" direction to counter act the drop. So when the trap is opened up and the crab drops and weight drops from the trap it starts to rise.
I just need the hauler to hold the load when the directional control valve is centered.
Any idea of a solution? Thanks
The creep is most likely leakage through the DCV center position. Check out the pilot to open check valve in the Hydraulic Schematics lecture at: ua-cam.com/video/NsgShyrcvqA/v-deo.html
Jim Pytel thanks for the reply I checked out the video
It may take a dozen views to grasp it
My creep has gone on since the system was brand knew. Is it likely the dcv would have that much leak from new?
I've read that motors are prone to have creep. But find it hard to find the solution
A counter balance valve seems like it might work
You can’t prevent the creep on any hydraulic motor using valves. You need to use a mechanical brake.
Some systems can integrate either a hydraulic activated brake band on the winch drum or buy a hydraulic motor with integrated hydraulic brake system/s.
Hey there. I'm a little unclear about how the CBV maintains the back pressure to allow for controlled retraction. If I remember right you were saying that the pilot monitored pressure ensures that pressure on the input never drops below set value. I see how that would keep the valve open but I can't wrap my head around where the back pressure is coming from.
If the pressure drops below the set value the CBV returns to the deactivated closed state. Given no passage to tank, back pressure supports the descending load.
Never mind.. should have finished the video before asking
Thank you kindly sir
Is there a specific reason for the 45 degree pilot lines?
No. Some manufacturers use all 90s.
Yes some do. I think the ANSI standard use 90 degree. And the ISO 1219 standard has a 45 degree line going in towards the valve instead of away from it. Not that the standards are flawless or worth following in every detail but I think ISO 1219 is good for at least for the basic proportions of symbols and so on.
The 45 degree line away from the valve is new to me.
Can I know the difference in working of a direct directional control valve and pilot operated directional control valve please
A "pilot" signal is any low power signal that shifts a primary device. Pilot signals could be oil based, air based, or electrical. Check out the "piggy back" valve example in the directional control valves lecture at: ua-cam.com/video/QaagWlHbxr0/v-deo.html
How you getting 1.460inch square
Ring like rod end area equals area of the cap minus the area of the rod. Check out the hydraulics math lecture at: ua-cam.com/video/NDrauWbUmFw/v-deo.html
@@bigbadtech ok thank you
Very informative video, but the flat-voice narration makes it hard for the viewer to remain focused and distinguish the key points.
No offence intended, I think that you should work on that and try to add some more vitality and pace variation to your storytelling.
No offense taken. I remember this one ... I was exhausted! My dad tricked me into residing his house and I knocked out maybe 5 lectures in one day. Never again! I'm not usually this robotic and you're not the first that noticed my deadpan delivery for this lecture. Ordinarily I'm a little more animated. Check out some of the newer material.
Duuuude, you are nasal
.. hold your nose, speak
amazing