Do you know for sure where and how many checkvalves there are? The reason I ask is that if there is only one topside that you can remove without having to pull the pump, there is a distinct possibility of resurrecting the failing one in the pump. The checkvalve holds better if it has pressure against it so it might seal if it is the only one.
Also, if the pressure then won't hold it may suggest that there is a hole in the pipe.
There could be a checkvalve somewhere on the drop pipe or even buried between the well and the house. Tee in a pressure gauge where the PRV is and see what it has to say.
Also, watch/listen for any sign of waterhammer and/or any other noise at the wellhead. Unless valveman is spot on and there is a small hole letting in air and slowly letting it back out, you should see some evidence of waterhammer if the issue is checkvalve failure.
You might want to get a pumpman or wellman on-site to render an opinion and then plan accordingly.
The fact that the pipe is under a vacuum means the pump will fill this void faster than if there is no vacuum. So if the pipe is under a vacuum, the pump should not have to run 10 or 30 seconds to refill the pipe. But if the check valve at the bottom is bad and there is a hole in the upper section of the pipe, it would take a while to refill the pipe, the same as it does the first time the pump is started when the pipe is empty.
The “big brass fitting” where the pressure switch and gauge are connected is a check valve. You can pull the guts out of this check valve and still use it as a place to screw in the pressure switch and gauge.
I'm calling around to see if any of the wellman have a portable puller since I have made it difficult to get a truck to the pump house.
Last edited by Bobo; 08-27-2012 at 12:30 PM.
Have you put an ammeter on the circuit to see what the pump is drawing during that first 30 seconds?
The sound at the tank when it is nearly full is likely the bladder sticking and then slipping on the inside of the tank. As for air if there is any, if you have a softener and/or iron filter, it could act as an air accumulator that then purges when backwashed.
this would agree with us simple pump guys.....
btw the vacuum in a barometer is made by outside air pressure, there always is a dead airspace at the top of a mercury barometer.
Last edited by bcpumpguy; 08-27-2012 at 08:30 PM.
That said however, any vessel designed only for pressure, should not be subjected to a vacuum as it could collapse. It's been known to happen to composite hydro-pneumatic tanks and to water softeners, etc.