Step 5 · Install the New Expansion Tank
Prepare the threads on the new expansion tank for a watertight seal. Take the roll of Teflon tape and, holding the tank with the threads facing you, wrap the tape clockwise around the threads. Use 3 to 4 full wraps, pulling the tape taut so it sinks into the grooves of the threads. Wrapping clockwise ensures the tape won't unwrap as you screw the tank in. Carefully lift the new tank and align its threads with the female fitting on the water pipe. Screw it in by hand for the first few turns to prevent cross-threading. Once it's hand-tight, use the pipe wrench to tighten it an additional 1 to 1.5 turns. The tank should feel snug and secure; do not overtighten.