Well pump check valve question...

[Absent Minded Farmer]

I'm wondering why, when the pump shuts off, the check valve sounds like someone has dropped a bowling ball on a kettle drum. Literally!! Not all the time either, maybe 35% of it. No pattern to it. It'll do it when the water hasn't been run all night or while the sprinkler's on. We changed out the pressure tank about a year ago. The bladder had ruptured(?). That's the story we got, anyhow.

So, is the check valve bad? They won't tell us over the phone until they come out to pull it up & have a look. I think it's a crock, personally. Not that the valve might not actually be bad, just that their full of beans because they don't get paid over the phone for consultation. Quite frankly, if they're going to dork me around, I'll pull the darned thing myself & look at it.

Which brings forth another question:
Is there a correct term for the clampy-thing used to hoist PVC out of the well?

Thanks,
Mike

 

[rodgernbama]

I"m thinking the check valve is ok if the tanks holding pressure. May possibly be air in the system making that sound. Might try bleeding pump.

 

[David G]

I would not worry about it unless pump is short cycling.

 

[Anonymous-0]

Do you have a sub Pump? one that is down in the well? If so it may have a check valve on it that is only working part of the time, That would make the one in the house clang like a train car comeing to a stop. Not only does it have all the water from the house side pushing it shut, Now it has 0 psi on the pump side To help softing the blow when the pump shuts off. Just hits that seat like a sleghammer. Far as the clampy thing goes if you have pvc drop pipe you need a crane or rig as the pvc has a good chance of beeing 21 ' long joints, Even if it's only 10'6" long joints there a good chance of it breaking off. Then you would have a ell of a mess. Fixed more pumps and well Than I want to think about.

 

[Russ from MN]

Possibly your pre-load in the pressure tank is not correct. It should be 3-5 psi below the cut in pressure, if it's too high it can make strange things happen. Like others have said, if the tank holds pressure overnight, the check valve is fine, and having multiple check valves should make no difference. For sanitary reasons there should only be one in the well, but many people install one by the tank because it's more accessible.

 

[Absent Minded Farmer]

I've kept an eye on it, & it doesn't seem to bleed off over night. I believe it only has the one check valve in the system. Is the pre-load pressure checked from the valve stem on top of the tank?

Mike

 

[Absent Minded Farmer]

Yeah, it's a sub. Hangin' out at 238'. I've noted at the gauge, that it runs a 50 - 70 cycle. The old tank was set to cycle 40 - 60. Is the pump unhappy with the upgrade in pressure? The guys that put it in said we could use it with all the water we use in the garden & to keep up with the power washer. Does that sound about right to you? We haven't had any major issues until our old tank setup gave up the ghost about five years ago. We're on our second tank since.

As for pulling up the PVC, your statement is quite what I feared. Compounded with Murphy's Law... uh yeah, no thanks! That brings up a question: why use flimsy, inferior to cast, PVC? Water certainly doesn't taste any better.

Guess I'll check my pressure & burp the system this weekend.

Thanks!!
Mike

 

[Absent Minded Farmer]

No, no short cycles. Just clunks shut with a bang.

Mike

 

[Absent Minded Farmer]

I'll bleed the system this weekend & see if there's any air or if it makes a difference.

Thanks,
Mike

 

[Anonymous-0]

Well if you have a pump hang at 200" or more I don"t think they would of used flimsy pvc. But still real hard to handle in long joints. they don"t used polly pipe on deeper wells cause it likes to twist when the pump comes on, Can"t used steel cause it rusts off. I thought maybe you had a deep well when you were talking about the check valve slaming shut, When you have 200ft of waterline you have a lot of weight on the pump, then add 60 or 70 psi. and there"s a lot of pressure pushing on the pump, that is why a lot of times you will find a check vale at the pump AND one at the tank, the one at the tank helps take psi off the pump. I would drop the psi back to 40-60 or 50-60. It could bee air, But I feel it"s going to be a bad check valve at the pump.

 

[Stubbyie]

You mention the pressure tank got changed out.

My bet is the check valve you used to have got replaced and a swing-type check valve was installed.

A water well system needs a spring-loaded or spring-type check valve.

What you describe happening sounds like the swing-type check valve flapper slamming shut.

Take a look at your plumbing near the tank and see if the check valve there (or elsewhere in your system) looks sort of like a 'T' with a knot on top, often a big hex nut-looking cap.

If your installer used a swing-type check valve in a water pump installation you got a bad deal due to ignorance or laziness.

If you can break into the system remove the flapper-type check and replace with a spring-type.

Or you can cripple or disable the flapper-type by unscrewing the top and removing the flapper...

BUT...

You MUST have a check valve in the system. If you disable the flapper check you have to install a spring check elsewhere in the line between the now-disabled flapper check and the first faucet.

I always install two spring loaded checks using unions so can be changed out. This way if one fails in service the other will keep the system working.

Without a check valve the water will reverse, drop down the tubing to the pump, spin the pump backwards, and if it tries to cycle 'on' while being turned backwards can snap a shaft but more likely simply trip a breaker or over time weaken the motor.

Please post back how you proceed so we may all learn.

 

[Russ from MN]

Yes, with all the water pressure bled off.

 

[Chip812]

Water hammer. Your check valve is going bad...

 

[Anonymous-0]

I think you are 100% right! Forgot all about that.