Bracker's Well Help Pages -Captive Pressure Tanks-

Bracker's Well Help Pages -Captive Pressure Tanks-

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Captive Air Tanks Hold The Air And The Water In Separate Containers Within The Tank. If your not sure of the type of tank you have, You must find out before doing anything for the purpose of this information!

Checking a captive air style tank for well water systems:
Includes manufactures;
Well-x-Trol, Con-Aire, Flo-Tec, A.O. Smith, Well-Rite, Clayton Mark, and all other diaphragm and bladder tanks I know of at this time. (It would be wise to find out your type and model.)

You must go threw all the checks, unless you find one that says the tank is BAD. Or you get to the end. Read this entirely first before you decide to do anything!

(Warning removing the air cap can void the warranty on some tanks.)
First check: If you press the air valve on the tank and water comes out. The Tank is BAD. (Most manufactures recommend: to remove the tank, turn it up side down and press the valve. If water comes out, the tank is BAD.)

(The information below assumes that you only have one tank in the system, or you'll have to add the tanks drawdowns together to receive the correct information for more than one tank.)

Second check: Make sure no one else runs water. Run water until your pump starts. Stop running water until the pump shuts off. Make sure your not losing water anywhere else. (Things to check for.) Run water in a bucket or container that you know the volume of and measure that amount of water until the pump starts again. This amount is called the tanks drawdown.
The size of the tank, and pressure setting, determines the amount of water you should have, or drawdown.
For instance if your tank is the size to hold approx. 36 gallons of water, should it be filled completely with water. That being a Well-X-Trol Model #WX203, a Con-Aire #CA75T, or #CA82T, A.O. Smith #V-100 to name a few. It should hold about 10 gallons of water at a '30 P.S.I. to 50 P.S.I. pressure switch setting'. If your tank is a Well-X-Trol #Wx202, or Con-Aire #CA42A, A.O.Smith #V-60 and or, looks like it would hold approx. 20 gallons of water if filled completely. Then at the '30 P.S.I. to 50 P.S.I. pressure switch setting', it should hold about 6 gallons.
If your tank has the approx. correct amount of water in it, then it "appears" to be good, and is doing its job correctly. But if you have less, or just want it to be working at its best, let's go threw the next check. If the tank is low on air, it should have air added.
Should your tank be another size, manufacture type, or have better information imprinted on the tank. Then you should follow the information on the tank, or retrieve the information from your tanks manufacture or its representative, as the figures above are general figure's for those approx. tank sizes and types.

Check Three, "Checking the air on a captive air style tank";
Shut the power off to the pump. (IF THIS IS A NON SELF PRIMING PUMP, YOU MAY LOSE PRIME; "I would recommend not doing this check unless you know how to and are willing to re-prime it.")
Run the water out of the system until the pressure gauge runs down to 0 P.S.I., and the water stops running from the open tap. Next take a tire pressure gauge and check the pressure on the tanks air valve. Most manufactures recommend 2 P.S.I. under the cut-in pressure, or pump start pressure, of the well pump.(*Note: This is set by the pressure switch.) So if the water pump is starting at 30 P.S.I., then the air in the tank at this time should be 28 P.S.I..
("I would say in this case: "28 to 25 P.S.I. is acceptable.")

Lastly Adding Air: If the tank is short of air, air can be added with an air compressor and with a tire air chuck, into the air valve on your tank. A tap must be open during this process; I would recommend a tap with out screens like a washtub tap. Or one could even connect a hose to a tap by the tank if there is one, or even an out side tap would also be a good idea, being careful so there is no back flow from laying that hose in anything that could back-siphon. *Note: Some taps have back flow preventers. I further would suggest bypassing and, or, not using any appliances that use water, before adding air. And afterwards clearing all lines. For a list of appliances check out this window. (Be careful some tanks maximum pressure maybe as low as 75 P.S.I., and also this will allow some dirty water from the tank to enter your system for a time, as the tank flushes out.)
Note from the author: Even though I've done this so many times I wrote this from memory. There are maybe some things that I've not included due to weighting the need vs this becoming to confusing to be of any worth. As you can see, it is simple, but with all the differences in systems, age, type and condition, it is hard to cover all instances. But the main thing is you will be able to see if a contractor does a good job when they do it. :)

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