Viton (FKM) seals excel in chemical processing and high-temperature applications, resisting acids, hydrocarbons, and steam up to 400°F. In Fig. 2002 unions for cementing lines, FKM's low permeation prevents gas leaks in volatile environments. 90 durometer variants provide firm compression for 20,000 psi ratings, with ozone and weather resistance for outdoor exposure. Sour service vers... https://globalsealstech.com/product/hammer-union-seal-2/