SR safety relief valves are designed and constructed to meet the requirements of Section VIII ASME Boiler and Pressure Vessel Code and ANSI/ASHRAE 15-2007 safety code for mechanical refrigeration. The SR safety relief valve meets the requirements for new installation and municipal ordinances. Precision machined moving parts of stainless steel and a PTFE disc prevent sticking due to corrosion or cold welding, to assure valve opening at the set pressure long after installation.Product Features:SR Series Designed to meet ASHRAE 15 2001 requirements for new system installations.Certified by the National Board of Boilers and Pressure Vessel Inspectors.All Stainless Steel Internal Parts.PTFE Seat.Accurate and Dependable.Pressure settings 150 psi to 400 psi.