Union type expansion joints are the choice when an economical threaded pipe connection is needed. They are engineered to absorb thermal movement, offset and misalignment in piping systems. Due to the design of the union type expansion joints having a rubber body it eliminates metal to metal contact stopping the electrolytic process. The union type expansion joints comes standard with galvanized ductile iron female unions. SS304, SS316 and Bronze unions are also available. The union type expansion joints are also available on special request with the following female union threads: NPT, BSPT and other standards.