Product Description: Groco PST-1 Pressure Storage Tank A pneumatic pressure charge, matched to the pump cut-on pressure prevents waterlogging by separating the air charge from system water pressure with a rubber bladder. The result is smooth pressure delivery, even temperature mix in showers, and reduced pump cycling. Mounts in any position and anywhere in the cold water plumbing after the pump. May be used for fresh or salt water. Operating pressure up to 100 psi. Mounting hardware included.