These adjustable, spring-loaded poppet valves are used to limit system pressure. Excess pressure unseats the poppet, allowing flow with minimal increase in system pressure. As fluid is released the system pressure decreases until the spring force re-seats the poppet. Kepner's Flexible Seal Seat™ ensures bubble-tight shutoff of liquid or gas. The relief pressure can be set using a tamperproof internal adjustment screw. Standard and specialty valves handle a wide variety of applications requiring fast acting relief performance and tamperproof pressure adjustment. Features and Benefits: Flexible Seal Seat™ for zero leak (bubble-tight) seal Outer O-Ring provides non-pressurized threads Both O-Ring seals positively secured Wide relief adjustment range 50 to 2000 PSI (3.45 to 138 bar) Tamperproof Nylok® adjustment to set relief pressure/prevent slippage Poppet stop inside valve body prevents spring from bottoming out