It's great that you produced this informational video about residential fire sprinkler systems. One note of correction would be that a typical sprinkler system would be designed to provide at least 13 GPM per sprinkler for standard spacing (16 ft spacing) sometimes more(for larger spacing) sometimes less if there is poor water pressure and special low-flow sprinklers and reduced spacing were utilized but even then it would be more than 4 GPM. Your flow test illustrates this by showing approximately 16 GPM flowing if you were to extrapolate your flow for a one minute interval. Also your pressure reading may not return to where it was previously after a flow test due to the check valve trapping excess water pressure due to pressure surges or thermal expansion which gets relieved when you perform the flow test.
Before opening the flush valve, check the pressure on the gauge in your garage. It usually will be between 50 - 70 psi. When you open the flush valve the pressure will drop initially but should return to approximately the same pressure you had before you opened the flush valve. If it does not then your valve in the garage is frozen shut which means the sprinklers will not have enough water pressure to put out a fire in your house. A Fire Protection service can either fix or replace this valve for you. I highly recommend this as my valve was frozen and had to be replaced 2 years ago. I now check it every 6-12 months just to be sure. Hope this info helps.
The configuration in the video is specific to houses built at Trilogy at Vistancia in Arizona, so I am not sure about your exact configuration. The flow switch that operates the electric bell is suspect. If you can access the flow switch unit you can test the cable going into it with a non-contact voltage detector to see if voltage is available at the switch. If not, it may be as simple as a blown fuse or circuit breaker. If voltage is available, I would focus on the mechanical switch which may be seized by mineral build up in the piping system. Especially if the system has not been flushed regularly. This sounds crewed but check valves and flow switches have been known to free up with a wrapping from a wooden dowel or rubber mallet. This may free it up but it will most likely occur later if the system isn't regularly flushed. If these options do not work you may have to contact a fire system service. Unfortunately, the Fire Switch unit usually has security fittings (screws) that prevent access to those without the tool to open them.
It's been a couple years since I did this video. I do remember the K factors were 4.2 & 4.9 for the sprinkler heads used here. The flow switch operated at >4ppm and the flush valve (as shown in the video was about 16gpm with the 1" CPVC piping.
It's great that you produced this informational video about residential fire sprinkler systems. One note of correction would be that a typical sprinkler system would be designed to provide at least 13 GPM per sprinkler for standard spacing (16 ft spacing) sometimes more(for larger spacing) sometimes less if there is poor water pressure and special low-flow sprinklers and reduced spacing were utilized but even then it would be more than 4 GPM. Your flow test illustrates this by showing approximately 16 GPM flowing if you were to extrapolate your flow for a one minute interval.
Also your pressure reading may not return to where it was previously after a flow test due to the check valve trapping excess water pressure due to pressure surges or thermal expansion which gets relieved when you perform the flow test.
The best video to learn residential fire sprinkler system. Thank you
Before opening the flush valve, check the pressure on the gauge in your garage. It usually will be between 50 - 70 psi. When you open the flush valve the pressure will drop initially but should return to approximately the same pressure you had before you opened the flush valve. If it does not then your valve in the garage is frozen shut which means the sprinklers will not have enough water pressure to put out a fire in your house. A Fire Protection service can either fix or replace this valve for you. I highly recommend this as my valve was frozen and had to be replaced 2 years ago. I now check it every 6-12 months just to be sure. Hope this info helps.
Thanks Doug, great job with this. Lived here about two years and always wondered how it worked and what to do. Now I know.
Nice job with the video. It will be helpful as I will be moving to a house in Peoria with sprinklers soon.
Very informative, thank you.
Nice video! when I run the test the bell used to turn on and ring, but not anymore. I have excellent flow. How can I approach this to troubleshoot?
The configuration in the video is specific to houses built at Trilogy at Vistancia in Arizona, so I am not sure about your exact configuration. The flow switch that operates the electric bell is suspect. If you can access the flow switch unit you can test the cable going into it with a non-contact voltage detector to see if voltage is available at the switch. If not, it may be as simple as a blown fuse or circuit breaker. If voltage is available, I would focus on the mechanical switch which may be seized by mineral build up in the piping system. Especially if the system has not been flushed regularly. This sounds crewed but check valves and flow switches have been known to free up with a wrapping from a wooden dowel or rubber mallet. This may free it up but it will most likely occur later if the system isn't regularly flushed. If these options do not work you may have to contact a fire system service. Unfortunately, the Fire Switch unit usually has security fittings (screws) that prevent access to those without the tool to open them.
Hello Doug. I’ve been using the flush valve as a hose line... I never knew this. What does that mean?
wanna try using the formula Q=k√p to explain how you got 4 gpm from a head
It's been a couple years since I did this video. I do remember the K factors were 4.2 & 4.9 for the sprinkler heads used here. The flow switch operated at >4ppm and the flush valve (as shown in the video was about 16gpm with the 1" CPVC piping.
9:42 you don't have a "CO2" detector, you have a "CO" detector. CO2 is carbon dioxide, CO is carbon monoxide.. just saying..