Well Mystery

[worthingtonwarren]

The pressure guage of my well water tank, which has a bladder, recently started shooting rapidly back and forther between 60 psi and 85 psi. It didn't do this all the time but it did so repeatedly and often. The well folks came and determined that the tank had virtually no water in it. Eventually they checked the air pressure valve that measures the pressure of the air above the bladder and found it was about 80 psi, and they hypothesized the the pressurestat kept turning the pump off as soon as it turned on because it was sensing the high pressure exerted by the bladder. So they released the bladder air from the valve on the top of the tank so that the pressure was close to 60 psi. After doing that the pump would start pumping when water was drawn from a faucet and water was now directed toward filling the tank. The pump then turned off when the tank had water in it and the pressure rose to 85 psi or so, the way it was suposed to. With the water in the tank, the pump wouldn't turn on until a substantial amount of water had been drawn. In other words, it seems to be working the way it was designed to work..

Here is my question: If the high air pressure above the bladder was the problem, had that air pressure increased over the years? If it always was set at 80 psi, why did it work until recently? If the air pressure recently increased, how did that happen since I know that no one used a compressor to increase the air pressure? I can understand how pressure might decrease over time through a nano leak of some kind, but how can the pressure increase without using a compressor to force more air into the space above the bladder? So although I am glad that the system seems to be working now, neither I nor the repairmen can figure out why it is working now.

Thanks for your time.

Warren

 

[sarg]

Was the system shut down and the pressure tank empty of all water when the "air pressure" in the tank was checked ?

 

[Stout Mechanical]

The bladder has a hole in it. You will need to replace the tank. The pressure will start creeping up again.

 

[arctic bill]

the same thing happened to me where i over filled the expansion tank .

 

[worthingtonwarren]

The bladder has a hole in it. You will need to replace the tank. The pressure will start creeping up again.

Thank you for your reply. I will happily replace the tank if that is the problem, as it well might be. However I'm very interested in better understanding what is happening. On the face of things, I would suspect that a leak in the bladded would allow water to flow in both directions. Are you saying that water is being pumped from the well into the tank and through the bladder and that that incoming water is increasing the pressure above the bladder? If that happens, the water must be staying above the bladder and not flowing back to the tank area below the bladder, so that bladder is acting like a check valve, right? If the water is being pushed up through the ladder, why doesn't it return when the pumping stops?

Thanks, again, for taking the time to reply.

Warren

 

[Stout Mechanical]

It is typically a pin size hole and yes the water is only flowing into the airspace between the bladder and tank. Nothing to do with acting like a check valve.
1, Your air space is should be set 2psi below your cut in. The water side of the bladder is under more pressure, so that’s the direction the water flows.
2, Think of Your tank as a 2litter bottle turned upside down. And the bladder as an inflated ballon inside of it. If water leaks from somewhere on that ballon it will flow between the bottle and ballon towards the bottom. Even if you deflate the ballon the water can’t come back through unless it finds the same exact hole it escaped thru. Eventually the tank will become waterlogged and fail completely. Might be a week might be 6 months

 

[worthingtonwarren]

It is typically a pin size hole and yes the water is only flowing into the airspace between the bladder and tank. Nothing to do with acting like a check valve.
1, Your air space is should be set 2psi below your cut in. The water side of the bladder is under more pressure, so that’s the direction the water flows.
2, Think of Your tank as a 2litter bottle turned upside down. And the bladder as an inflated ballon inside of it. If water leaks from somewhere on that ballon it will flow between the bottle and ballon towards the bottom. Even if you deflate the ballon the water can’t come back through unless it finds the same exact hole it escaped thru. Eventually the tank will become waterlogged and fail completely. Might be a week might be 6 months

Thank you. That makes perfect sense and describes what I've been experiencing. It is a little surprising that the two repairmen, who had probably more than 50 years of experience between them, didn't realize what was happening. Nonetheless, I think you've nailed it and I appreciate your help. Thanks. Warren

 

[Valveman]

Something else your repairmen with 50 years experience don't know is what causes that problem. Cycling the pump on and off too much causes the failure of the pump and everything in the system. That bladder/diaphragm goes up and down with each pump cycle until it get a hole or tear like when bending a wire back and forth over and over. Stopping the cycling solves the bad bladder problem as well as several others, while delivering much stronger constant pressure to your house and shower.