Water Main Pressure
Water Main Pressure
(OP)
this is a quick one....
If I have a section of water main that has hydrant on it. The hydrant has a pressure guage that reads 60 psi (static). There are valves on both ends of the water main, which are then closed to isolate this section. What happens to the pressre at the hydrant when the valves are closed? Does the pressure go to zero?
Thanks.
If I have a section of water main that has hydrant on it. The hydrant has a pressure guage that reads 60 psi (static). There are valves on both ends of the water main, which are then closed to isolate this section. What happens to the pressre at the hydrant when the valves are closed? Does the pressure go to zero?
Thanks.





RE: Water Main Pressure
2nd scenario - valves are still watertight, but small amount of leakage somewhere between the valves and the hydrant - pressure drops
3rd scenario - valves do not hold perfectly - pressure stays at 60
RE: Water Main Pressure
If there is an elevation difference between the manholes, the static pressure would also be influenced by the elevation difference.
RE: Water Main Pressure
RE: Water Main Pressure
RE: Water Main Pressure
http://www.sewerin.com/us/about-us.html
RE: Water Main Pressure
RE: Water Main Pressure
If the valves don't leak by you can then either isolate the line and turn-off any services attached to it. Do a pressure test of the line up to about 100 psi and then monitor the pressure over a couple of hours to see if there is a drop in pressure. If you don't feel comfortable increasing the pressure just monitor to see if it drops below 60 psi. If all the services are turned off, any drop would indicate a leak.
Make sure that you don't have a leak where you connect the pressure gauge. If you find that you have a leak, if it is a major leak, you can then use the acoustic leak detection which should be able to pinpoint the leak.