Piston pump and hydro-pneumatic tank

[RetiredInGueydan]

Zero.

I am saying that if priming into a galvanized tank is easier than into a pre-charged pressure tank, then starting into an open drain valve would also make things easier. I am afraid I am trying to apply logic. Do you disagree with my logic?

I did not say that priming into a galvanized tank is easier. That was the pump company.

In part that you did not quote, I had discussed a non-priming thing -- the water level of the water drops to the level of the sand point screen while the pump is sucking. I would indeed expect the pump to be pumping a mix of air and water at that point. What would you expect? Jet pumps produce a vacuum. That sucks only water if there is only water at the screen. If the water level dropped, I expect to not suck only water.

I agree with your logic that an open drain valve is needed while priming jet pumps.

I have not commented on galvanized tanks in this thread.

Apparently I missed your discussion on non-priming which was a brief version of what you describe here. With the next door neighbor having a spring fed system, I highly doubt that Chucky's sand point well has supply issues. I would suspect a leak between the check valve and the static water level is the source of any air in the system.

 

[Chucky_ott]

I agree with your logic that an open drain valve is needed while priming jet pumps.

I have not commented on galvanized tanks in this thread.

Apparently I missed your discussion on non-priming which was a brief version of what you describe here. With the next door neighbor having a spring fed system, I highly doubt that Chucky's sand point well has supply issues. I would suspect a leak between the check valve and the static water level is the source of any air in the system.

1. Next door neighbour, which is my cousin, has a piston pump drawing directly from the lake. Not sure where spring fed system came from. My sand point is about 20ft from the lake and is in sandy soil. The water table is 12" below grade, even during the driest period of the year. Everything about the sand point is below water. No water supply issues.
2. Air is only a problem during the lengthy priming process each spring. It seems like it takes about a week of occasional use (maybe 20 pump cycles in addition to the 10 I do when I prime the pump) to completely purge the system. Next year, I'll try priming with an open faucet and for a longer period of time.
3. Air may also get in the pump when there is a power outage and the pressure tank is depleted of water. My best guess as to the cause is the pump elevation. It's higher than the tank and some of the fixtures. If a faucet is opened and all the water drains out, I'm guessing air can get in and migrate uphill to the pump. Would a loop and vacuum breaker on the discharge side of the pump prevent the pump from draining?

 

[Sponsor]

 

[Reach4]

I would suspect a leak between the check valve and the static water level is the source of any air in the system.

Slathering any joints with aerosol shaving foam and pumping would be a worthwhile test for such vacuum leaks. While the pump sucks, a leak will suck in lather.

It's higher than the tank and some of the fixtures. If a faucet is opened and all the water drains out, I'm guessing air can get in and migrate uphill to the pump. Would a loop and vacuum breaker on the discharge side of the pump prevent the pump from draining?

Having the check valve as close to the water intake as practical would help. Sucking from a lower altitude seems like it would help.

Also be alert for signs that the check valve leaks water back down, and replace the check valve if it leaks. Pump cycling when no water is being used would be a sign.

 

[RetiredInGueydan]

1. Next door neighbour, which is my cousin, has a piston pump drawing directly from the lake. Not sure where spring fed system came from. My sand point is about 20ft from the lake and is in sandy soil. The water table is 12" below grade, even during the driest period of the year. Everything about the sand point is below water. No water supply issues.
2. Air is only a problem during the lengthy priming process each spring. It seems like it takes about a week of occasional use (maybe 20 pump cycles in addition to the 10 I do when I prime the pump) to completely purge the system. Next year, I'll try priming with an open faucet and for a longer period of time.
3. Air may also get in the pump when there is a power outage and the pressure tank is depleted of water. My best guess as to the cause is the pump elevation. It's higher than the tank and some of the fixtures. If a faucet is opened and all the water drains out, I'm guessing air can get in and migrate uphill to the pump. Would a loop and vacuum breaker on the discharge side of the pump prevent the pump from draining?

My cousin, who has a cottage next to ours, still uses a 50+ year old piston pump. I set it up in the spring. It self primes and doesn't cause any problems. Ever.

Please excuse the error, I read this as being a spring fed system.

 

[Chucky_ott]

Slathering any joints with aerosol shaving foam and pumping would be a worthwhile test for such vacuum leaks. While the pump sucks, a leak will suck in lather.

Having the check valve as close to the water intake as practical would help. Sucking from a lower altitude seems like it would help.

Also be alert for signs that the check valve leaks water back down, and replace the check valve if it leaks. Pump cycling when no water is being used would be a sign.

Check valve is just above the sand point. It doesn't leak. Pump is 36" higher than the water level. Pump is also approximately 24" higher than the lowest fixture about 100ft away in another cabin. Next year, I'll lower the pump about 24" and will consider putting a vacuum breaker on the discharge side. That's what I did for the hot water tank to prevent it from syphoning out and as recommended by the HW tank manufacturer.

Current system and possible source of air during power outage:

 

[Bannerman]

Your drawing shows a higher section of pipe after the pump, then shows the path to drop lower before entering the pressure tank. If the drawing is showing the path accurately, then air can continue to remain trapped within the higher pipe section instead of flowing into the hydro pnuematic tank. Once under pressure, trapped air will become compressed to a smaller volume, but the trapped air will expand again in volume as the pressure becomes lower. This maybe a reason for the priming issue.

Suggest eliminating any raised pipe sections before the pressure tank where air can potentially become trapped. You may need to elevate the tank somewhat to ensure a straight path with no potential for air to become trapped before the tank.

If the check valve directly above the sand point is sealing fully, water should not drain back into the well, even when there is power loss causing the pressure tank to become fully depleted during water use.

If the HP tank contains additional air than the tank is capable of holding naturally (uncompressed) while there is no water contained, then any excess air will exit out into the plumbing system when the tank becomes depleted. Once fully primed, unless there is a leak in the piping between the well and pump, or at a fitting, the check valve will prevent the excess air from pushing water backward toward the pump, but the air will instead be forced forward toward the home's fixtures when water is consumed. Air exiting into the piping after the pump, should not cause a priming issue, unlike air before or directly within the pump.

Verify that the only check valve, is the one located at the sand point.

 

[Reach4]

I don't see a vacuum breaker helping priming.

 

[Chucky_ott]

Suggest eliminating any raised pipe sections before the pressure tank where air can potentially become trapped. You may need to elevate the tank somewhat to ensure a straight path with no potential for air to become trapped before the tank.

That's the plan for next spring. My diagram is somewhat accurate but it's worse than shown. The pump actually sits higher than the tank. Next year, I'll elevate the tank so that its intake port is higher than the pump's discharge port, making sure there are no loops in the piping.

And yes, only one check valve at the sand point.

I guess I'll skip the piston pump for now and keep what I have. Hopefully the new configuration will help. The pump house is like 80 years old and needs to be rebuilt. I might bring 220v to it as well and get a cycle sensor.

Thanks all for the discussion.

 

[Reach4]

I guess I'll skip the piston pump for now and keep what I have. Hopefully the new configuration will help. The pump house is like 80 years old and needs to be rebuilt. I might bring 220v to it as well and get a cycle sensor.

https://www.electricmotorwholesale.com/SymCom-111P-ENCL/ is a pump protector for 115 (120) volt.

Getting a well drilled with a 4 or 5 inch PVC casing would mean no priming. Get a pitless adapter, and no heated well house needed.

Substantial cost, but a 1/2 HP submersible in a not-deep drilled well can supply a lot of water. Silently. No drama.

 

[RetiredInGueydan]

1. Next door neighbour, which is my cousin, has a piston pump drawing directly from the lake. Not sure where spring fed system came from. My sand point is about 20ft from the lake and is in sandy soil. The water table is 12" below grade, even during the driest period of the year. Everything about the sand point is below water. No water supply issues.
2. Air is only a problem during the lengthy priming process each spring. It seems like it takes about a week of occasional use (maybe 20 pump cycles in addition to the 10 I do when I prime the pump) to completely purge the system. Next year, I'll try priming with an open faucet and for a longer period of time.
3. Air may also get in the pump when there is a power outage and the pressure tank is depleted of water. My best guess as to the cause is the pump elevation. It's higher than the tank and some of the fixtures. If a faucet is opened and all the water drains out, I'm guessing air can get in and migrate uphill to the pump. Would a loop and vacuum breaker on the discharge side of the pump prevent the pump from draining?

For next year, with the suction line laid above ground on uneven terrain and the sand point as you described. I would start by removing the suction line from the pump, secure it 4' above grade and fill it completely. Then due to the uneven terrain walk down the line lifting it waist high to the sand point, turn around and do the same returning to the pump. Refill the suction line and repeat the process until the pipe no longer takes water, then reattach to the pump. Fill the pump completely, open a drain valve after the pressure tank and start the pump. There should be a solid stream of water until a slug of air comes up from the pipe below the check valve. This may cause a loss of prime, if so just refill and restart the pump and discharge water until there is no air visible. This should be the one and only time that priming is necessary for the season. If air does return to the system, the only source would be the pipe below the check valve and would need to be corrected. Also, air cannot get trapped on the discharge side of the pump, water use removes any air and is not a cause for concern.