The 455 Series regulator provides primary pressure control of highly corrosive gases such as chlorides, sulfides, and other acid-forming gases. It features a Dursan® treated capsule and diaphragm. This proprietary amorphous silicon oxide finish offers significantly more corrosion resistance than 316L stainless steel and exotic metals such as Hastelloy®. For fluorine service, CONCOA passivates the regulator with a stainless steel CAPSULE® and diaphragm, creating a complete assembly with all peripherals. CONCOA strongly recommends using a deep purge assembly with the 455 Series regulator to prevent introducing moisture into the process gas stream, which could form acids and eventually lead to corrosion.