How to Install a Well Pressure Tank & Set the Air Pressure

Turn off power to the pump system at the circuit breaker and turn on the faucet located at the lowest point in your home and allow it to run long enough to drain the water from the system.

Cut the pipe that connects the old tank to the water supply using a hack saw. Cut as close to the tank as possible to ensure you have enough pipe for the new installation.

Disconnect the check valve assembly from the well pump suction pipe and remove the old tank.

Glue a 12 inch piece of PVC pipe into a PVC male adapter using a Teflon-based compound. Match the diameter of the pipe to the diameter of the water supply pipe. The diameter of your male adapter will reduce or increase the pipe size to fit the tank.

Apply about four layers of Teflon tape to the tank elbow. You may find it easier to do this with the tank lying on its side.

Tighten the male adapter onto the tank elbow using two adjustable wrenches. Hold the tank elbow in place with one wrench while tightening the adapter with the other. Do not turn on the power or connect the tank before adjusting the air pressure.

Place a bicycle tire pressure gauge on the tank’s air valve, which is typically located on top of the tank and use this to read the tank’s pressure.

Find the factory-set pressure on the inside of the pressure switch cover. On a 20 to 40 psi pump switch, the factory-set cut-in pressure is usually 20 psi. On a 30 to 50 psi pressure tank it is 30 psi, and on a 40 to 60 psi tank it is 40 psi. The proper cut-in pressure is 2 to 4 psi less than the tank’s pre-set pressure. For example, the cut-in setting on a 20 to 40 psi pressure tank would be 16 to 18 psi.

Adjust the tank’s air pressure using the air valve to release air from the tank until the gauge reads 2 to 4 psi less than the factory cut-in pressure.

Connect the tank piping to the household water piping and seal the connection with Teflon tape or a Teflon based compound.

Connect the tank’s check valve, which is typically located at the top-front of the tank, to the well pump’s suction pipe. Apply Teflon tape to the connection to ensure the connection is airtight.

Open several cold water faucets and then turn on the power to the tank. Allow the pump and the faucets to run for at least 10 minutes or until faucets run with full water pressure to flush the system of air and sediments.