AMSE NB Certified: Liquid, Gas, Vapor, Air and Steam 800 Bronze Safety and Relief Valves are available in sizes 1/2 to 1-1/2 inches. They are available with a plain, open or packed cap design. Optional bronze or SS seats and choice of soft seat materials. Suitable for pressure from 5 to 900 psig and temperatures -400 to 422 ° F.