Suction on supply line and air in water (well)

[Madscientistii]

Hi Everyone,

I'm diagnosing a well issue. Long story short a splice broke in the supply line from the well to house. Introduced a lots of fines over the years... (don't ask, that's the long story.) I found the broken splice and repaired it.

We've been flushing the system for a couple of weeks now to remove the fines from the pressure tank. After about a week to week and half, the faucets begin burping out air. (Yes, I bled the air out the system once the splice was repaired)

The pressure tank, while old (wx-203 install date 1988), appears to be holding its charge pressure and no water is exiting the schrader valve . (we will probably replace tank anyway, since it doesn't seem to be clearing the fines)

After the pump kicks off, there is a slight drop in pressure on the system 1-3 psi, but after that, it holds.

There is a check valve at the pressure tank, but depending on what you read here at the forums, that should probably go away.

When the supply line from the well is disconnected from the pressure tank, there is a slow, but significant suction.

The well appears to be keeping up with recharge when looking down the pipe. Static level is about 20ft.

The pump may have been replaced in 1997. Looking down the well, the casing look bone dry.

Should there be any suction at all on the supply line from the well?
Does the suction on the supply line indicate a bad check/foot valve? A leak on the pipe in the well? (Air is getting in the system)
Do I really have to pull the pump and if so, do I need to replace pump or just replace pipe and check ?

Thank you for your insights.

 

[Reach4]

I infer you have a submersible pump.

If you gut the topside check valve, the leakage at the check pump at the pump may reduce or even stop. If there is a tiny leakage, the water in the pressure tank can compensate, although the pump might have to start every so often. That might be every 12 hours or every 12 minute, depending.

See if you can quantify the suction. Maybe you can connect a hose that dips into a bucket, and see how long it takes to suck a gallon of water.

 

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[Valveman]

Removing the above ground check valve might make the check on the pump start holding. If you still lose pressure when no one is using water the check on the pump will need to be replaced. You can just add a check valve to the old pump, but many times pulling the pump is such a job people will opt to replace the pump while they are at it.

 

[Madscientistii]

I infer you have a submersible pump.
...
See if you can quantify the suction. Maybe you can connect a hose that dips into a bucket, and see how long it takes to suck a gallon of water.

1) Yes, Submersible pump.

2) After several time trials, the average is just under a minute per gallon. (1/gpm ) draw back.

3) Is there supposed to be any drawback? I only had a 3 gallon bucket, but I think it would have kept sucking if I kept adding water.

4) How can I be sure there is a check valve on the pump? I found a manual nailed to rafter above the pressure tank for a sub pump with an install date of 1997. If that is true, then the manual only states to install one some where in the line. it doesn't mention a built in valve...

5) also, we are getting a lot of metal bits in the water. My suspicion is this coming from the pressure tank, since we don't see them in the water before the tank, but maybe its an over time thing...

6) air in system. still.

Just trying to give you as much detail as possible. Thank you for your insights.

 

[Reach4]

It is possible that the original tank was a "galvanized" tank, and there is a leak on purpose about 5 ft or so down, but there is a check valve at the pump. Is there a Schrader valve near your check valve? If you get air on a continuing basis, this seems more likely.

It is possible that you never had a check valve at the pump. It is possible that you have a failed check valve at the pump.

Until you pull the pump to fix things for any reason, your workaround is 1. to keep the above ground check valve in service. 2. Check for who will do your pump work via neighbor recommendations etc. 3. Accumulate cash into your well fund to be ready.

Having a vacuum in that line means that you could suck in contamination through a leak.

5) also, we are getting a lot of metal bits in the water. My suspicion is this coming from the pressure tank, since we don't see them in the water before the tank, but maybe its an over time thing...

The WX-203 is very unlikely to be the source of the metal bits.

How long does your 32 gallon WX-203 take to fill? Maybe watch that time. If the time starts increasing, the pump may be gradually failing.

 

[Valveman]

If you did not have a check valve on the pump the pipe would take water as fast as you could pour it with a fire hose.

 

[Reach4]

After the pump kicks off, there is a slight drop in pressure on the system 1-3 psi, but after that, it holds.

I think that early drop off is normal. https://terrylove.com/forums/index....lbs-of-pressure-at-cut-off.67940/#post-504741 I suspect it is mostly the pressure tank diaphragm and plastic piping relaxing, but it could include my check valve taking a bit of time to slowly seat.

A follow up test could be to run water rapidly to reduce pressure to maybe 45 psi, and record the pressure action when I turn off the water. Diaphragm and pipe relaxing from before could cause the pressure to increase, as at the 30 minute mark in the graph in https://www.uponorpro.com/~/media/Extranet/Files/manuals/PLU_PressureTest_IS_0812.aspx?sc_lang=en

 

[Madscientistii]

Thank you again for the great replies.

1) so basically, there should be no vacuum on the supply, unless the check valve at the pump has/is failing or there is no check valve at all.

2) the wx-203 (from 1988) only takes about 2 minutes, if that, to fill from empty.

3) air? coming from pump side or tank side.? If left alone, the faucets will sputter air in about a 1.5 weeks. consistently. Then I re-bleed the tank and lines and the process starts over.

 

[Reach4]

1) so basically, there should be no vacuum on the supply, unless the check valve at the pump has/is failing or there is no check valve at all.

I can't agree with your conclusion. When you have water below a check valve, even the tiniest leak or temperature drop could cause a vacuum. Your 1 gpm test is meaningful. It says you either have a leak at the check valve, and/or you have a leak somewhere else. You missed my Schrader valve question.

2) the wx-203 (from 1988) only takes about 2 minutes, if that, to fill from empty.

Since it takes about 8 gallons to fill that enough to turn off the pump, that would seem to imply that the pump is only delivering about 4 gpm. There is a good chance that is a drop off from the original performance.

3) air? coming from pump side or tank side.? If left alone, the faucets will sputter air in about a 1.5 weeks. consistently. Then I re-bleed the tank and lines and the process starts over.

A leaking under-water check valve by itself would not explain air coming in. There could still be a vacuum with mostly water vapor in much of the pipe, but that would condense back to water once under pressure.

 

[Madscientistii]

... You missed my Schrader valve question...

My apologies, no schrader valve

...Since it takes about 8 gallons to fill that enough to turn off the pump, that would seem to imply that the pump is only delivering about 4 gpm...

My time estimate to fill the tank was from a completely empty tank, 0 psi. From cut on pressure, it takes less than a minute to cut off. (30/50)

...There could still be a vacuum with mostly water vapor in much of the pipe, but that would condense back to water once under pressure.

I do not understand this statement. Wouldn't the lines be filled with water, especially after flushing the lines with water from the pump and no air coming out?

Some what related, when I spliced the supply line, I did NOT use any putty on the connectors. I just heated up the black poly pipe (gently with hair dryer) and inserted the connectors then clamped them down. Re tightened the next day. No water is leaking from the repair, but could air be getting by? I don't hear it.

 

[Reach4]

I do not understand this statement. Wouldn't the lines be filled with water, especially after flushing the lines with water from the pump and no air coming out?

Suppose there is only an under water leak of any sort below your above-ground check valve. The weight of the water above will drop the water until the vacuum in the pipe can hold up the water that is above the water level in the well. The maximum vacuum compared to the atmospheric pressure is about 14.something psi which is roughly 30 ft of water --depends on the barometric pressure. Now you could think that the space is empty, but it actually will have water vapor.

So for a good explanation, look up a description of how a mercury barometer works. Mercury is heavier, so the vacuum can only hold up about 30 inches of mercury. The space above the mercury column contains mercury vapor at a very low pressure.

 

[Madscientistii]

Suppose there is only an under water leak of any sort below your above-ground check valve. The weight of the water above will drop the water until the vacuum in the pipe can hold up the water that is above the water level in the well. The maximum vacuum compared to the atmospheric pressure is about 14.something psi which is roughly 30 ft of water --depends on the barometric pressure. Now you could think that the space is empty, but it actually will have water vapor.

So for a good explanation, look up a description of how a mercury barometer works. Mercury is heavier, so the vacuum can only hold up about 30 inches of mercury. The space above the mercury column contains mercury vapor at a very low pressure.

Got it. btw, the well depth is somewhere between 78ft and 50ft depending on who you ask.

If you believe the paper nailed to the rafter, then there is 39' of pipe and static water level is 20' when I measured it.

so basically, i've got to pull the pump which is the only way to know, right?

 

[Reach4]

Probably pulling the pump will make sense.

Do you have a pitless adapter? If you have a bad o-ring in the pitless, that could cause leakage. If I had a pitless, I think I would gut the topside check valve. Take the well cap off. Have a bright flashlight at night or a mirror to direct the sun in the bright sun. Turn on the pump. Look and listen down the casing.

 

[Madscientistii]

Probably pulling the pump will make sense.

Do you have a pitless adapter? If you have a bad o-ring in the pitless, that could cause leakage. If I had a pitless, I think I would gut the topside check valve. Take the well cap off. Have a bright flashlight at night or a mirror to direct the sun in the bright sun. Turn on the pump. Look and listen down the casing.

Yes to pitless. No visible water around the pitless (or the casing), but there is considerable corrosion. But then again, the whole pipe has lots of corrosion. Its very very very very old. The story I hear is that it was converted from pit to pitless in 1977, beyond that date is just guessing.

 

[Reach4]

What is the casing at the surface -- 5 inch steel?

No visible water around the pitless (or the casing), but there is considerable corrosion.

No visible water on the outside of the casing at the pitless, or inside? Unless the pitless is under pressure (pump running if top check valve has not been disable), you will not see or hear leaking.

Will you pull the pump yourself, or have that done? Do you know how to pull the pitless adapter?

 

[Madscientistii]

What is the casing at the surface -- 5 inch steel?

I don't know what the casing width was when it was a pit well, but the current casing is 6 and 5/8" OD steel. They welded the extension to be above ground.

No visible water on the outside of the casing at the pitless, or inside? Unless the pitless is under pressure (pump running if top check valve has not been disable), you will not see or hear leaking.

Both. I still have the exterior casing exposed down to the pitless. The splice repair was not far from there. I've been watching it with the pump running and not running.

Will you pull the pump yourself, or have that done?

Its looking like I will pull it with the help of friend (hopefully.) Its either 50' or 40' down.

Do you know how to pull the pitless adapter?

I need to get/borrow the T-bar to thread on to the adapter. My concern is it is fairly corroded. (see photo) I should probably brush off the area, but I didn't want to knock down too much into the well.

Once the bar is threaded, I should just be able to pull up on it correct?

 

[Madscientistii]

Update. Pulled pump and found a 4 millimeter hole in the reducing adapter on the pump. The brass was thinning on one side and failed.

My attempts to remove adapter successfully, failed. New pump it is.

However, this problem solved only revealed more problems... I think a rehabilitation is in order.

@Reach4, Vacuuming the pitless was a brillant idea and worked perfectly!

Thank you @Reach4 and @valveman for your suggestions. They were very helpful!