Bladderless water tank question

[nickel plate]

I have a "Quick Tanks Inc." model # Q120VW max working pressure=75PSI galvanized bladderless above ground residential water tank that operates on induced air pressure. It has a metal air valve stem near the tank in the water line that when the well pump turns on to replenish the water storage, the valve stem weeps/leaks. I bought a new valve stem from a local irrigation supply and installed it and no more leaking. When swapping it out after turning off the electricity, there was no rush of air or water from the valve stem hole.
Can you please post on how to drain the tank and re-charge the air pressure to the system? The electric pump controller is set for 30-50 PSI. I called the manufacturer and requested an owner's manual-they basically told me that is not information they hand out and I need to contact a well drilling company for assistance??? I'm tyring to avoid that if at all possible as I have an air compressor and hopefully can do this myself if someone can walk me through it.
Thanks in advance.

 

[Turbys_1700]

Just drain out the tank...
You may need to put in some air to get more of the water out...
Once you get it drained then air up the tank to 28 psi...
The pressure in your tank should be set 2 psi below your low pressure switch setting...
In other words, 28 psi for a 30/50...38 psi for a 40/60...etc...
I just replaced my pressure tank in my spring house...
It was a 14 gal bladder tank that was going on 25 years old...
Finally developed a leak and had to replace...

 

[TheGoose]

Different style tank.

Add air to the system while letting out water. Keep the pump off. When you've got about 1/2 air to water you're good. If you add too much air it won't hurt anything, it will just come out of the piping in spurts. Sometimes you can feel the tank while filling and see where the water is at.

Just drain out the tank...
You may need to put in some air to get more of the water out...
Once you get it drained then air up the tank to 28 psi...
The pressure in your tank should be set 2 psi below your low pressure switch setting...
In other words, 28 psi for a 30/50...38 psi for a 40/60...etc...
I just replaced my pressure tank in my spring house...
It was a 14 gal bladder tank that was going on 25 years old...
Finally developed a leak and had to replace...

 

[Willl]

I had a bladderless before it rotted out and converted to a bladder style.

But I remember mine having a float valve also on the tank that bled off extra air. Yours has this also ?

 

[gwdixon]

I have lived in houses with wells and bladderless tanks. One used to pump air from an agricultural well and filled the tank with air. That one was easy. Just put in a float valve that bleeds off air like Willl stated.

The other, and current tank, gets waterlogged. That requires air be introduced into the tank on a periodic basis. If you don't then the pump will cycle on and off way too much and cause premature failure.

About halfway up the holding tank is a plug that can be used for a float for air release or a fill point for air. I installed a air hose quick connect after a shut off valve. That way the air hose can be attached, the valve opened, and a rush of air enters the tank. Installing a tire-type valve is WAY too slow of a flow of air.

The way I determine if air is needed is to open the valve and if water comes out then air is needed. Shut off the pump, drain the tank until just barely no water comes out of the quick connect, then hook up the air hose. After the pressure gets to the "pump turn off" reading (50 or 60 psi) then close the valve and remove the air hose. Don't forget to turn the pump back on.

If too much air was added then it will cause pulsing in the lines and bursts of air will scare your wife (if applicable). Also, you may have many very small air bubbles in the water as the air dissolves in the water under pressure.