Raccorderie Metalliche and compressed air plantshttps://www.racmet.com/en-ww/compressed-air-plants.aspx All inoxPRES joints are pre-fitted EPDM O-Ring, compatible with any plants, Class 1 to Class 4 (ISO 8573-1/2001) and approved PN16. ... The choice and the implementation of the piping type or system, depending on the type of application is responsibility of the planner/installer. ... According to the type of plant, [...]