The BURCAM 600542B 5 US gal (20L) inline captive air pressure tank is designed for water systems assembled with a jet pump.  It has a tough epoxy-baked finish for durability and a replaceable bladder made of synthetic butyl rubber to increase reliability and life span.  There is no water to metal contact for rust-free operation.  The tank has a stainless steel flange with 1" NPT connection. It supports a 100 PSI maximum working pressure. For use with a 20/40 PSI pressure switch, the air pressure must be adjusted to 18 PSI; for a 30/50 PSI switch, the pressure must be adjusted to 28 PSI.  Drawdown 1.6 US gal (20/40 PSI); 1.3 US gal (30/50 PSI)