Reasons to Change Pressure Tank

[frank1492]

This is actually a two-parter but I'll post the second question separately. My GF has a deep well with a submersible pump and a pressure tank that is probably 30 years old. Lately, the pump cycles constantly when she runs the water, or does a wash . I think that can only mean one thing- that the bladder has ruptured and the tank is waterlogged. I have told her this constant cycling will dramatically reduce the life of the pump over time which will be one huge expense for her. Am I correct that (a) constant cycling shortens the life of the pump and (b) the cause in this case is probably a waterlogged pressure tank? Thanks for help. Frank P.S. I will have access to the tank in a few days. Maybe an easy way to tell is to press the valve stem and see if water comes out?

[dpb]

frank1492 wrote: ...

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Yes and yes...

If it's not completely full on the air side (of water, that is) and there's not a very big leak you may gain some time by draining fully and then repressurizing to the proper setpoint pressure.

If successful it'll stop the incessant cycling and last a few days to weeks...

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[frank1492]

But I guess you are saying get a new one ASAP? (Thanks for your help.)

[Frank]

I'd say yes but as dpb suggests you could defer temporarily by adding air. If bladder is broken it will not last long. I've replaced 2 in house's 35 year life because they leaked.

[dpb]

... Well, a new one is likely in your future sooner than later...

How long you can limp along w/ the present one will depend on the state of how bad the bladder/diaphragm actually is. I've managed to put it off a few months on the rare occasion; weeks is generally the time span before the cure doesn't last long enough that you'll become tired of fooling with it.

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[frank1492]

If the pressure is below 40lbs, can I easily use a standard bicycle pump to restore the pressure? (Wow- this house is 40 years, never had a tank replaced she says!)

[Steve Barker]

yes, and yes. But even with a busted bladder, you should be able to air up the tank to solve the problem. The bladder merely separates the two, so airing up doesn't have to be performed as often. Turn the pump off and air the tank to about 7 psi less than the pump kick off pressure.

s

[Steve Barker]

Yes, my dad pumped ours up when i was a kid with a hand pump a couple times a year. (he worked up a sweat doing it also)

[Stormin Mormon]

I'd have to guess that a bike pump would do the job. But, a heck of a lot of work.

I'd want to use a bigger compressor. Minimally a lighter plug job, running off a charged battery jumper pack.

[Stormin Mormon]

Short cycling the pump (brief, frequent runs) does shorten the life of the pump.

I wouldn't want to press the valve stem to check for water-- that just guarantees to let out the air. I'd want to juice it up with a compressor.

Someone with real life experience will likely tell me I'm wrong. But, if the bladder is ruptured, sounds like you can inflate it up to a fairly high PSI, like 60 PSI. Any excess air added will bubble out the faucets, next time you run water. Might sputter and spray. But at least you'll have added all it will take.

[Harry K]

Correct pressure (with tank empty) is 2 psi below pump kick-in pressure. No, the excess air won't come out. The air is at the top of the tank, the water outlet of the tank is at the bottom.

Harry K

[trader4]

The 2 psi below turn-on sounds about right to me. Also, besides a ruptured air bag, the air valve could be leaking. I'd try re- pressurizing it first and see if the air holds. Also, depending on the conditon of the tank, you could buy a replacement air bag.

[dpb]

Stormin Mormon wrote: ...

Well, if it is indeed a leaky bladder/diaphragm (depending on which style tank OP has), it either has too high an air pressure now if water has displaced any significant air volume and there's not been a loss of air as that means same amount of air in lesser volume.

That would be the wrong way for sure...

I already told OP to drain the tank (water side) entirely, then repressurize to the correct setpoint pressure (2 lbs under on setpoint pressure). That will restore proper operation as well as can be w/ the existing air volume on the air side as it should be. As previously noted, how long it will last will depend on how much water has been accumulated on the air side already and how bad any leak is. OP should check and ensure that the air valve isn't leaking, though, w/ the soap/spit test just in case as well as checking the air pressure after draining to make sure hasn't just lost air. In that lucky event he may have a pleasant surprise.

The only possible use of higher air pressure is in a diaphragm-style tank one can sometimes manage to force a little water to the other side of the barrier w/ pressure over a long period if can do w/o the pump for a day or so. It's almost impossible w/ a bladder given the shape as a bag.

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[Harry K]

Yep, some tanks do have replaceable bags. Considering the miserable job it is to replace one and the relatively minor cost of a new tank...

Harry K