This high flow, zero leak, low pressure drop check valve suitable for most fluid and gas applications. Its fully guided poppet has a free floating O-ring design which is extremely tolerant of particulate contamination. A metal to metal positive stop in both the open and checked position protects O-ring and spring from over-stress fatigue. Zero external leakage is achieved by the utilization of a static Viton O-ring seal with TFE backup ring. When specified with the proper seal material, these valves are ideally suited to cryogenic system applications. Specifications: