Hammer Union Seals (Weco Seal) are used in hammer union-style pipe connections to establish flow lines and prevent leakage. They are used in the Oil & Gas Industry, in steel mills, chemical plants, strip mining, and marine dredging.

JST Hammer Union Seals are available in a range of configurations and materials to match the specific performance requirements of your demanding operating environments.

Some profiles such as Fig 2202, Fig 1004, Fig 1502, Fig 2002, Fig 602, Fig 1002 etc require a Hammer Union Lip Seal or an 'O'Ring depending on the Size of the Hammer Union.

JST produce 2",3", and 4" Hammer Union Seals in Nitrile (also known as NBR, Buna, or Buna-N) for standard service, as well as Viton (also known as fluoroelastomer or FKM) for increased temperature and chemical resistance or HNBR for Sour Gas Service. In addition to the standard molded rubber seals, anti-extrusion rings can be reinforced in brass Hammer Union Seals or stainless steel Hammer Union Seals.