http://www.lindeseals.com/hammer-union-seals/ Products Description Hammer Union O-rings help prevent leakage in hammer union pipe connections. Generally applied in applications within the Chemical Processing, Offshore Drilling, Petrochemical, and Water and Gas industries. Materials include Nitrile (NBR), Viton庐 FKM, HNBR, and PTFE. In addition to the standard elastomer materials, anti-extrusion rings can be reinforced in Stainless Steel or Brass. Product name Color Size Application Hammer Union O-rings Black, red, green, blue, etc Standard/Custom Union, Valve, Pressure manifold MaterialSpecial Applications Buna-NHydrogenated Nitrile (HNBR) improves ozone and weather resistance FKMCustom compounds improve chemical and low-temperature resistance. EPDMGood for water, steam, solvents and acids SiliconePopular for food and medical applications FluorosiliconeLow outgassing, used in military and aerospace applications NeopreneUsed in refrigerations industry for resistance to ammonia and Freon Hammer Union Seals suppliers website:http://www.lindeseals.com/hammer-union-seals/