The Chlorine Pressure Gauge Assembly consists of a 4 1/2" 30/0/300 pressure gauge mounted on a welded design diaphragm seal. Carbon steel upper housing with 1/2" NPT instrument connection, tantalum diaphragm, nickel/chrome plated carbon steel lower housing on threaded seal, welded Hastelloy® C lower housing on flanged seal. Gauge face is filled with silicone oil and gauge seal is filled with halocarbon.