I recently purchased a farm with a well. I would like to verify and adjust the pressure on the Challenger (Flexon Industries) 33.4 gallon, model PC122R diaphragm well tank. It has a yellow sticker on top that says 38psi. Under that someone wrote with a sharpie LRPS 3-19-04. There is a automobile style valve on the top with a cap on it.

Is it as simple as inflating a tire? Does the tank need to be full or empty of water during the process of verifying and adjusting the pressure?

I recently purchased a farm with a well. I would like to verify and adjust the pressure on the Challenger (Flexon Industries) 33.4 gallon, model PC122R diaphragm well tank. It has a yellow sticker on top that says 38psi. Under that someone wrote with a sharpie LRPS 3-19-04. There is a automobile style valve on the top with a cap on it.

Is it as simple as inflating a tire? Does the tank need to be full or empty of water during the process of verifying and adjusting the pressure?
To set the air pressure in a bladder tank, look at the cut-in pressure on your pressure switch. Now drain the line down with the pump off. When there is no more water coming out of the hose bib, set the pressure in the bladder tank at 2 lbs. below the cut-in pressure om the control box. Check it with a tire gage. If your pressure control is set to come on at 20 PSI and go off at 40 PSI then your gage should read 18 PSI. Hope this helps and thank you for rating my reply. Tom

SB is correct as usual. I would only add that you need to verify the cut in pressure. Sounds like someone has adjusted the tank before on 3/19/04. Turn on water and watch the pressure gauge until the hear the switch "click" to turn on the pump. The pressure on the gauge at that point is your cut in pressure.