Pump Question

[Tony Clifton]

Replaced a pump a few weeks ago. Plumbed everything up, primed it, and she was working beautifully. Shut off the water, take a peek at the pressure gauge, and the needle is dropping slowly. Turn off the ball valve that I installed about 2' away from the output and the pressure keeps dropping - actually started dropping faster.
WTF?
I understand that a pump can only lose pressure on the output side - if leak was on input side it would lose prime.
Vendor (very knowledgable) can't think of anything (tells me to replumb which I I did and still same problem.) He calls pump manufacturer and they said that it could be the leathers or footvalve.

Any thoughts???

[irritation]

a footvalve seeping

[Mike Leary]

What is the water source, Tony? And why did the other pump fail?

[Tony Clifton]

Thanks irritation - I have heard that in certain situations (but not all?) that the footvalve will cause that to happen.

My guess is the the other pump failed for 2 reasons. 1 being that it was an ancient, cheap looking pump. The other being that it was cycling due to the pressure loss - I always tell clients that I am replacing the pump - can't really start troubleshooting until you can see whats going on.

[BrandonV]

How fast is it loosing pressure? Very well could be a footvalve, ifnits a lake make sure it's off the bottom as to keep it from sucking silt. Did you go
Straight off the pump w/ PVC? Maybe you have a tiny leak there OR is your pressure relief valve possibly stuck? That happens too.

[Tony Clifton]

It loses about 15-20PSi every 15 minutes or so. It's on a well.

[Mike Leary]

can't really start troubleshooting until you can see whats going on.

I am not a pump guy, that being said, whenever I had my driller out, he'd ask, "what gpm and pressure do you want." You have to know a lot of things before you bore the pump guys to death. Sounds like a small break or leaking fitting.

[irritation]

Could take hours even days to lose prime with a footvalve seeping, depends on the system.

[Beartooth]

Without going into a lot of details, you can definitely be losing psi on the suction side of the pump. Use common sense and start in the most noticeable places first, i.e. connections, foot valve, etc. What kind of suction line do you have? PVC, galvanized, poly? What is th esize of the suction line? And how deep is the well and where does the bottom of the suction line sit in relationship to the bottom of the well? Answer these questions first to help you find the "root" of the problem.

[Wet_Boots]

Assuming you have a sound pump, and all your work is perfecto, you can add a fine-mesh strainer to the outlet, and follow that with a check valve. It might just be that there is enough sediment present to keep even a brand-new foot valve from seating.

[Beartooth]

Boots...Why the check valve after the filter? Never seen this application in the field before, just curious?

[AI Inc]

I think he means putting the check valve on the intake just before the pump to supplement the foot valve.

[Wet_Boots]

No, I mean on the outlet. For my own work, I always have a check valve on the inlet of a shallow-well pump, but if I was pulling up enough sand to foul a check valve, then I'd need to have a strainer upstream of the check, in order to be certain it would function reliably, and having a strainer on the suction side of a pump kind of bothers me. For one, you couldn't open a drain to blow the screen clean.

[AI Inc]

Do you usualy make these automatic flush , with an electric valve on program b doing a 1 min flush?

[Wet_Boots]

I haven't needed that yet. Got one rusty deep well that can foul the stainless screen to the point of needing hand cleaning. Not sure what I'll do there.