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.