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

 

[rswyan]

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

That’s how I do it.

 

[California]

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

That sounds simpler than draining the system.

And less likely to get any sediment moving.

 

[ruffdog]

How often should this be done?

I check mine every couple of years. Normally I do it when I'm using water outside like watering the yard or garden.

 

[ning]

That sounds simpler than draining the system.

And less likely to get any sediment moving.

If there's any water in the system when you go to adjust the air pressure you'll end up with an inaccurate reading, because with the faucets off there nowhere for the water to go, so you don't know that the bladder finished expanding unimpeded.

Open the valves, leave them open while adjusting.

Or, don't. A small discrepancy in the pressure will affect the drawdown capacity only a small amount.

 

[California]

If there's any water in the system when you go to adjust the air pressure you'll end up with an inaccurate reading, because with the faucets off there nowhere for the water to go, so you don't know that the bladder finished expanding unimpeded.

Open the valves, leave them open while adjusting.

Or, don't. A small discrepancy in the pressure will affect the drawdown capacity only a small amount.

Huh? This land is sloped. Every faucet save the one at the pumphouse is lower than the tank.

Seems to me that just getting the water level in the plumbing lower than the tank, and leaving the faucet at the pumphouse open to the air, gives the zero pressure you need for an accurate measure.

Draining everything at the far ends of the several underground lines seems unneeded. Do you have a reason for that?

 

[Egon]

Drop the tank pressure to zero (shut pump off and open a faucet) and then set the bladder pressure.

 

[Ltcmikesr47]

bleed

Hey, if ya don’t know, don’t mess around. GOOGLE or call a pro!!

 

[California]

Hey, if ya don’t know, don’t mess around. GOOGLE or call a pro!!

Where's the fun in that?

The manufacturer's instructions weren't clear re periodic testing years after the original install.

In many instances, real experience related by the brain trust here makes more sense than whatever Google will bring up, and often adds context that isn't found elsewhere.

Like any research source, you need to cast out nonsense answers then go with what several credible folks have said.

 

[Valveman]

Any faucet in the system will drain the tank. Just want the pressure gauge on the tank to read zero when checking the air at the top of the tank with a tire pressure gauge. Those two gauges usually read a couple pounds differently. But if not the pressure at the top of the tank should be the same as the water pressure gauge when the pump is on. I usually use a little less air like 5 PSI less than pump start, because it is not good to have a little too much air in the tank. The faucet would run out of water for a second or two before the pump starts if there is too much air in the tank.

Glad you doing it yourself and doing the research. Now you can research even further to figure out what causes the bladder in the tank to tear and the air to get lost in the water. If you stop the cause of the problem, you should never lose air from the tank. I have one that hasn't needed any air since I installed it in 1984. Only air it loses is from me checking it, so I only check every 10 years or so. But I also have a device that tells me my pump is cycling too rapidly, which is what happens when you lose the air charge. What some people call "normal" pump cycling will still flex the diaphragm in a tank up and down until it breaks like bending a piece of wire over and over. Reducing or eliminating pump cycling will not only make your tank last longer, but will make the pump and everything else last longer as well. To stop the cycling you need constant pressure, which also makes for much stronger shower pressure.

 

[steve tym]

The tank needs to be empty of water to properly check the air charge. Period. The air charge should be 2 pounds less than where the pump turns on. Less air means more cycling. Too much air, as valveman stated will cause the pump to hesitate before the pump turns on.
Cycling is bad for every part of your system, that's why the proper air charge is important.
If you cannot drain all the water out of the tank, there is something wrong with the tank. At some point the diaphram inside will fail.
Valvemans valve helps limit the number of cycles. (Valveman will be proud, we just installed one today.)