My old gage has some water on the inside of the dial,and I need to change it. There's no shut off valve on the line coming in from the water pump to the tank so ill have to turn the pump off and drain the tank to replace the gage. I believe my tank has an air bladder because there's a valve on top of the tank to receive a hand held air pump. How do I adjust the air pressure in the bladder after my repair to what it is presently?

Good morning Walter,

Your air setting on the tank should be 2 pounds UNDER the cut in point in the pressure control box. If your pressure control has a 20 PSI cut in and 40 PSI cut out the tank pressure should read 18 PSI. This should be done with the pump off and no pressure in the system. Hope this helps. Tom

Usually it is 2 psi under the cut in pressure. Most tanks come with decals giving the procedure. Be sure to shut the water off to the house before shutting off the pump and draining the tank.