Slow Loss of Pressure from Well Line

[Don H]

I recently installed a new well pump, check valve, piping and wire in my 100', 6" PVC cased well. The original pump was 32 years old and still working but I was getting the well pipe banging in the basement so I figured it was the pump check valve. Pulled the pump and sure enough the check valve was bad. I saw no sense in reinstalling the old pump and plumbing so everything was replaced new except the pitiless adapter. The pump is a Myer 1/2hp, 12 gpm.

Since the install I notice a slow drop in water pressure on the tank gauge. If I shut the well line valve off the pressure drop stops. The pressure will drop from 60 to 40 and cause the pump to kick on in about 4 hours. The pressure tank, HW heater, filter and all fixtures are past the shut off. This tells me the leak is between the main shut off and the pump.

Looking down into the well I have a limited view of the water 40' below. With the pump running I do not see water spraying out from a broken pipe or the pitiless adapter. I did notice that with the pump off I can see rippling in the water surface below. Shutting off the pump and draining the pressure off the line I notice the water rippling stops, the surface is undisturbed.

Even though I can't see water spraying under pressure I believe the pitiless adapter O-ring is not sealing causing water to run down the outside of the drop pipe and drip onto the water below. I believe this is what is causing the disturbance of the surface and the rippling. I plan on pulling the pump up and replacing the O-ring.

Does this sound reasonable or am I missing something?

 

[Reach4]

I plan on pulling the pump up and replacing the O-ring.

Does this sound reasonable or am I missing something?

Reasonable.

https://terrylove.com/forums/index.php?posts/576904/ has some comments on grease. Other posts on that thread talk about obtaining an o-ring if you don't have the right one identified.

 

[Sponsor]

 

[Don H]

Thanks. I searched "pitiless" and read about 100 posts but no one mentioned the correct dimensions for the O ring.

 

[Don H]

I replaced the O-ring yesterday and it appears as though the drop in pressure has slowed but not stopped. It looks like a drop of about 2 psi per hour or half of what it was.

What would be an acceptable rate of pressure loss?
The next step would be digging up the Pitiless.

 

[Valveman]

I replaced the O-ring yesterday and it appears as though the drop in pressure has slowed but not stopped. It looks like a drop of about 2 psi per hour or half of what it was.

What would be an acceptable rate of pressure loss?
The next step would be digging up the Pitiless.

For me, an acceptable loss of pressure would be zero.

 

[Reach4]

I presume you are searching for pitless rather than pitiless.

I did notice that with the pump off I can see rippling in the water surface below.

Any rippling? I wonder if a laser pointer clamped steady would magnify ripple detection by affecting the beam reflected to a target. If rippling, maybe the next thickness up in o-ring would be worthwhile.

 

[Don H]

It appears as though the rippling has stopped.

The new O ring was a tight fit in the groove in the Pitless, I don't know if a bigger one would fit and stay in place. My local hardware store has a huge selection so maybe I'll take the old one and check.

The owner of the hardware store, which also does installs of pumps among other things, told me that if the O ring didn't work that replacing the Pitless would be next. He said our water is somewhat acidic and it is not uncommon to see a pin hole through brass fittings.

 

[Valveman]

He said our water is somewhat acidic and it is not uncommon to see a pin hole through brass fittings.

Ding, ding, ding, I think this maybe the problem.

 

[Don H]

I think it will have to wait until spring.