The 8400 Series Vapor Valve provides pressure relief in applications where hazardous vapors are to be piped away. The Vapor Valve is a non-ASME code valve and specifically addresses low-pressure applications (below 15 PSIG). The valve uses a spring that directly opposes system pressure. A fully guided, stainless-steel disc senses the system pressure. If the system pressure ever reaches the valve’s determined set pressure, the disc will release from its seated position, venting system pressure.