Abstract: A pressure rise rate limiter valve (10) is designed to limit a pressure surge of a gas or fluid through a rapidly opening valve, thus avoiding hazardous heat buildup in the system. The valve has an inlet port (14) and an outlet port (16) with a spool (24) having a passageway (32) communicating between the two ports. Said passageway (32) also communicates with a cavity (123) in the valve housing (12) through a restricted orifice (36) located at the end opposite the outlet port (16). The gas introduced at the inlet (14) is directed through a series of feeder ports (38) in the spool (24) into the passageway (32) wherein the gas is dispersed both toward the outlet port (16) and toward the cavity (123) in the housing (12).

Abstract: A check valve or relief valve is provided with a floating shroud having a retaining lip engaging with a downstream edge of a moving poppet to maintain the shroud and a captured seal ring in proximate relationship with the poppet to maximize the usefulness of the flow ports in the poppet and to eliminate seal ring flutter. The retaining lip of the shroud may have axially directed holes to create a reduction in pressure between the seal ring and the poppet seat to move the seal ring against the poppet seat during high flow conditions.