15776.805 VALVE PRESSURE PROTECTION PART NO : AB8431G ​ Williams Pressure Protection Valve Composed of normally-closed pressure-protection valve which are engineered for industrial and vehicular applications. With sufficient inlet pressure, these valves open to permit free flow of air. In the event of a system failure or a decrease in supply pressure, the valve will close to prevent any further pressure loss or reverse flow. Comes with filter - to reduce ingestion of contaminants.