This is the ASME-compliant Safety Relief Valve found on the ASME version of our SE(1) and SEII Industrial Optima Steamers. Made by Apollo Valves, this pressure relief valve is a crucial safety feature that your steamer cannot be operated without. If ever the pressure inside your Optima’s boiler begins to exceed 135 psi, this valve will mechanically open to safely release the pressure from underneath the steamer. If ever this valve is tripped, it’s recommended to bring your machine to the proper authorities in your area responsible for reseting and certifying the valve as part of OSHA’s guidance for ASME compliance.