How to set pressure on Well Tank?

[California]

The instructions say drain the tank then set the tank bladder air pressure 2 psi below the pump cut-in pressure.

But I need this clarified. The control is set to start at 40 psi, cut off at 60 psi. I found the tank pressure same as the water pressure at the well, 55psi, a few minutes after the pump had ended its run.

Do I simply turn off the pump, bleed the system at the lowest faucet, then get the tank pressure down (or up) to 38 psi? Or should I do something entirely different.

Advice needed!

 

[steve tym]

With the tank empty, you want the air pressure, measured at the top of the tank, 2 psi less than the turn on pressure. So, if the switch is set to turn on at 40 psi, set the air charge at 38 psi with an empty tank.

 

[steve tym]

Shut the pump off and drain the tank. If you check it with the pump on, the air perssure will be the same as the water pressure. Shut the water off to the house first, there may be sediment on the bottom of the tank, drain it from the bottom. You may have to purge the tank a few times to rinse the sediment from the tank. Maybe a lot of times.

 

[California]

I just re-checked, there's no drain. So we're back to the question in the first post.

 

[ning]

I just re-checked, there's no drain. So we're back to the question in the first post.

Turn off the pump
Drain the whole system
Somehow
You're sure there's no drain on the T in front of the pressure tank?
Is there a hose bib somewhere at or lower than the tank that you can drain water from? Make sure there's no check valve between the tank and the bib.

 

[ning]

The control is set to start at 40 psi, cut off at 60 psi. I found the tank pressure same as the water pressure at the well, 55psi, a few minutes after the pump had ended its run.

Aside from the drain question - if the switch cut off at 55 psi, either the switch isn't set right or the pressure gauge is reading wrong.

This has nothing to do with the air pressure in the tank; the air pressure will just adjust how much water will be held under pressure in the tank.

 

[LittleBill21]

I just re-checked, there's no drain. So we're back to the question in the first post.

turn off the power and just open a faucet till the pressure drops below 30, then use the air pump and set it at 38

 

[California]

Turn off the pump
Drain the whole system
Somehow
You're sure there's no drain on the T in front of the pressure tank?
Is there a hose bib somewhere at or lower than the tank that you can drain water from? Make sure there's no check valve between the tank and the bib.

I'm certain there's no drain on or near the tank, I just checked. The tank is on a short T, between the pump and the wall of the pumphouse. The pipe then goes out to a manifold with separate outlets to house, barn, garden, all these lines go underground. There's also a faucet on that manifold. No sign of a check valve, or anything to catch sediment.

I worked alongside a pro plumber replacing these underground water main lines a few years ago so I know what's there.

This is sloping ground so there are faucets downhill from the pumphouse that I can drain. Also I can open the faucet on that manifold at the pumphouse, to avoid a siphon vacuum and get true net zero pressure.

Aside from the drain question - if the switch cut off at 55 psi, either the switch isn't set right or the pressure gauge is reading wrong.

I should have been clearer, the control is properly set to 40/60. I observed 55 psi at both the pump and the air tank because some water had been used after the pump shut off.

Ok, the plan is:

Turn off the pump.

Drain water from a downhill faucet. With another faucet open at the pumphouse, the highest point in the system, so the tank sees neither pressure nor vacuum.

I don't see a need to drain the entire system, just the part near the pumphouse which is higher elevation than everything else.

Get the air pressure in the tank bladder to 38 psi.

Close the faucets, restart the pump.


How often should this be done?

 

[ponytug]

I'm certain there's no drain on or near the tank, I just checked. The tank is on a short T, between the pump and the wall of the pumphouse. The pipe then goes out to a manifold with separate outlets to house, barn, garden, all these lines go underground. There's also a faucet on that manifold. No sign of a check valve, or anything to catch sediment.

I worked alongside a pro plumber replacing these underground water main lines a few years ago so I know what's there.

This is sloping ground so there are faucets downhill from the pumphouse that I can drain. Also I can open the faucet on that manifold at the pumphouse, to avoid a siphon vacuum and get true net zero pressure.

I should have been clearer, the control is properly set to 40/60. I observed 55 psi at both the pump and the air tank because some water had been used after the pump shut off.

Ok, the plan is:

Turn off the pump.

Drain water from a downhill faucet. With another faucet open at the pumphouse, the highest point in the system, so the tank sees neither pressure nor vacuum.

I don't see a need to drain the entire system, just the part near the pumphouse which is higher elevation than everything else.

Get the air pressure in the tank bladder to 38 psi.

Close the faucets, restart the pump.


How often should this be done?

Just once, unless you start to have an issue with the pump cycling. In practice, for me with our bladder tank about once every 8-10 years.

All the best,

Peter

 

[ning]

How often should this be done?

When you install it