Well head noise issue. 1

[itsmoked]

I have a client's well that was in service but the guy had hung the 1-1/2HP pump 170 ft down by SCH40 PVC using the standard crummy slip to MALE threaded adapter couplings 5 years ago. A few weeks ago the pump that normally runs about 30 minutes once a week was seen running as the owner went to bed and then found running when they got up in the morning!

I was asked to check it and found that it was drawing the correct current but nothing was coming out of the well head. Further investigation showed the first adapter coupling had sheared dropping the entire motor pump and pipe riser down the well to the bottom where it dutifully ran for 8 hours in fountain mode all contained within the well.

We pulled the pump and since the hassle was so great replaced the entire pump and riser using sch80 threaded riser pipe and SS female/female couplings. The new pump was a Berkeley pump identical to the original Gould that came out.

It pumps the same 15gal/minute into the same 230 feet of dynamic head.

The problem is that instead of being dead silent at the well head like the typical well I'm greeted with the sound in the clip provided below. I'm pretty sure it's the check valve fluttering. Why?!? Why now? How do I stop it?

Do note that my camera greatly exaggerates the actual sound level of The Noise. The correct level is what you'd hear if you turned down your PC's sound to the lowest level that you can still detect the noise.

Well Head Noise Video

This is the checkvalve.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[1503-44]

Is it flowing when it is doing that?
It may be broken.
If not move it to a horizontal position.
Replace with a cushioned check.

 

[LittleInch]

What's that thing just downstream of the output?

Where is the waste going?

Can you measure flow rate?

Try flowing less flow or more flow.

Do you have the pump curve?

What size is that pipe?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[mk3223]

Is the check valve was installed correctly with the flow direction pointed down?
If the flow direction was correct, the check valve might be a "spring" check. And, my guess is that the noise might be coming from it, either something caught inside or broken spring.

 

[itsmoked]

Yes BI that's only when it is flowing.

What's that thing just downstream of the output?

Not sure what you're referring to?
There is a 1/2" capped PVC conduit sticking up or the Sch80 threaded coupling needed to help match the required rigid lengths to allow the union to function.

Where is the waste going?

What waste? This is a freshwater well.

Can you measure flow rate?

Yes, It's 12gal/min.

Try flowing less flow or more flow.

That I can do as there is a gate valve up by the tank.

Do you have the pump curve?

Not sure what you can use it for, but here it is;

The water table is 140 feet down from the well head.

What size is that pipe?

1-1/4" standard for most wells.


Any chance this could be caused by trapped air that will dissolve away and stop the oscillation?

Keith Cress
kcress -

http://www.flaminsystems.com

 

[itsmoked]

Hi mk3223;

Is the check valve was installed correctly with the flow direction pointed down?

Yes, it has been working fine -flow down- for 5 years. It was not making any noise when I last saw it a year ago. Then this failure occurred and of course there was no water flowing thru it until I got the well running again to now be greeted with the flutter.

If the flow direction was correct, the check valve might be a "spring" check. And, my guess is that the noise might be coming from it, either something caught inside or broken spring.

Ugh. I really don't want to remove it since the pipe projects from the concrete with only about two inches and if something goes wrong it will be very wrong. Also I'm going to get 55 gallons in the face. LOL But that may be what this comes to.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[1503-44]

I'll bet on a broken spring or clapper. With 12gpm it should be fully open and staying that way.

Scuba mask and snorkel could help with that.

 

[LittleInch]

Sorry. Autocorrect on my phone.

Where does the water go?

Now assume flow is up the central pipe and then down the one on the left. But what does it connect to?

What does that pressure guage read during operation? Does it fluctuate or flutter?

Last one. Is this a single phase pump?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[itsmoked]

Where does the water go?
Now assume flow is up the central pipe and then down the one on the left. But what does it connect to?

Correct assumption. Up a mountain to the top of an 8,000 gallon tank.

What does that pressure gauge read during operation? Does it fluctuate or flutter?

101 psig running, 23 psig not running.

Last one. Is this a single phase pump?

Yes. 17 stage centrifugal. Drawing 10.8A FLA is 11.0A


Keith Cress
kcress -

http://www.flaminsystems.com

 

[3DDave]

If you remove the upstream side from the check valve and the check valve is fine, there should be no flow, but poking it with something soft to unseat it may give a clue.

Perhaps it's just cavitation which will sort itself out.

It doesn't seem to me like there should be pressure pulsation from a centrifugal pump to trigger an oscillation in the ordinary functioning of a check valve, but if there is some other damage I can imagine several reasons for the flapper to rattle around in the flow.

Is there some way to alter the back-pressure to change the flow-rate and see if that changes the noise? A ball-valve right after that check valve is looking mighty handy right now.

 

[Artisi]

A stab in the dark, have you bled the air from the dead end leg after the pressure gauge?

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[itsmoked]

I'm trying to figure out how I'd bleed air. Doesn't seem particularly amenable to bleeding. I can certainly see trapped air being a cause as that can provide a compressible medium (energy storage) to drive an oscillator.

Originally I reassembled it with a long sweep of flex PVC to deal with the critical length issues caused by the plumbing seen in the photo above. That put a 90 directly above the check-valve. I figured the flutter was being caused by this new configuration delivering disturbed water to check-valve just a diameter or two away from it. So I reconfigured to what you see now moving the 90 back to the original location probably 5 or 6 diameters away knowing that it would cure the flutter.... Fail. No change at all.

3DDave; Yes. There is a gate valve in a sump at the tank about 600ft away and 200 feet above. That is likely the easiest thing to try. In my estimate the customer needs only about 1gal/min to easily meet all needs so I'll try restricting the flow from above.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Artisi]

Looking at you first photo, you show a "T" with a gauge at one end and what looks like a 90 deg. valve at the other end, has this valved been cracked on start-up to allow any air to escape?
It may be an ongoing problem if there is any air coming thru' the system.
It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[1503-44]

The brass valve.

 

[Artisi]

yes, the 90deg,M/F brass valve.

It is a capital mistake to theorise before one has data. Insensibly one begins to twist facts to suit theories, instead of theories to suit facts. (Sherlock Holmes - A Scandal in Bohemia.)

 

[1503-44]

Is the pressure gage jumping around, or constantly holding a mark?

 

[LittleInch]

It's a bit of an odd one for sure.

When running the numbers check out fairly well so your pump is running as predicted for 12gpm.

A few things to try / check out.

When the pumps is running can you stop it and observe the pressure? If the NRV is working then the pressure should fall fairly fast ( a few seconds). If it's failed then it will gradually fall as it's draining the outlet line back into the well.

If it falls fast to the 25 psi level, open that gate valve next to the pump and see what happens. The pressure should fall fast and the flow stops quickly.

then wen running again crack open that gate valve (it is now under quite bit of pressure) to see if air leaks out.

BI - if you look closely at the little video clip you can see the pressure gauge is actually very steady.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[1503-44]

Then I believe the valve is broken. It would seem that with that noise and a good valve, you would see some pressure pulsations.

 

[itsmoked]

Looking at you first photo, you show a "T" with a gauge at one end and what looks like a 90 deg. valve at the other end, has this valved been cracked on start-up to allow any air to escape?

That is a hose bib I installed when I initially got to the scene to get an understanding of the flow. (Zero)

I've had it full open, half open, and cracked open, during several starts. Water definitely comes rocketing out. Problem is air could be on the other side of the main Tee and it wouldn't have any motivation in coming out the hose bib. And, since that check valve is there the upstream water can't return from above to drive any air out of that side of the Tee. That said 12gal/min should drive air down a foot or so then up up up up to the tank where full pipe diameter flow exits into the tank.

But you guys have given me an idea. I added that 'other' side of the Tee stuff. It could be air is trapped in the gauge side? Can't be much. Oh, and earlier LI asked and now BI, looking very closely at the gauge I see no sign of the flutter on the gauge needle. Maybe because of air between the two?

I don't suppose we can divine anything from the frequency of the flutter?

LI; On start up the pressure surges to about 130psi then falls to 85 then climbs to 100~101 all in less than 2secs. Then sits rock steady as you've noted. When the pump stops the pressure drops to 24~26psi nearly instantly.

Note: there is also a check valve built-in at the top of the pump at the bottom of the well exactly 180 feet below.

I hear you BI. I think I'll let it run for a week which is sadly only going to be an hour or two and see what transpires before biting into CV replacement. I just hope the CV doesn't disintegrate and cause problems with all the subsequent, then available, head shoving the pieces back down the well to the pump.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[1503-44]

If the noise freq corresponds to the number of vanes in the pump x rps, maybe. Or that minus n. It could tell you if a vane has corroded ... or something. I'm no expert at freq analysis. Anyway, somehow I doubt that's your problem.

It would also seem that, if it was air, you would see some gage flutter due to its compressibility and water entering and reversing in that bit of pipe, but that's a WAG too.

Other than that, a broken check would not be the last thing I'd suspect. At least you shouldn't have to pull the pump. Finger crossed.