Features Leak-tight performance near set pressure allows higher operating pressures resulting in increased process throughput and system optimization. 2-piece body design with easily replaceable seat and seals reduces downtime and maintenance costs. FKM soft seat provides repeatable leak-tight performance before and after each relief cycle. Bubble tight at 90% or better of set pressure. Manufactured to ASME Section VIII UV for gas service. Relieving capacities certified by National Board of Boiler and Pressure Vessel Inspectors. Standard trim components in 316 stainless steel for maximum corrosion resistance. Optional trim to NACE MR-0175 (2002 Edition). Gas service only. Lift lever not available for air service.