Abstract: A suction valve for a reciprocating compressor includes a hollow cylindrical valve seat having a plurality of suction ports formed therethrough. The suction ports are covered by flaps moveably mounted on the inner surface of the valve seat which open and close in response to pressure differentials in the compressor. The flaps are oriented in a consistent circumferential direction so as to induce a vortex effect in gas moving through the suction ports.

Abstract: An unloader system for a reciprocating gas compressor includes an unloader valve assembly which may be installed as the suction valve assembly or the discharge valve assembly of the compressor. The valve assembly includes a valve seat having one or more seat passages formed therethrough and a valve guard having a number of valve members movably mounted thereon equal to the number of seat passages. One of the valve guard and valve seat is rotatable relative to the other. The rotatable member is driven by a constant torque motor or other power source which stalls when a retarding force caused by pressure differentials across the valve members overcomes the torque supplied. Once pressures across the valve members equalize, the rotatable member can resume rotation. A method of unloading a compressor using the unloader system includes selecting a rotational speed for the rotating member to allow backflow.

Abstract: An unloader system is provided for a reciprocating gas compressor. The system includes an unloader valve assembly including a valve member controlling flow between compressor cylinder and a clearance bottle. Opening and closing of the valve member is controlled by manipulating a control pressure acting through a manifold against the stem of the valve member by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: An unloader system is provided for a reciprocating gas compressor. The system includes an unloader valve assembly including a valve member controlling flow between compressor cylinder and a clearance bottle. Opening and closing of the valve member is controlled by manipulating a control pressure acting through a manifold against the stem of the valve member by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: An unloader system is provided for a reciprocating gas compressor having a cylinder, a piston reciprocably mounted in the cylinder, a rotatable crankshaft connected to the piston, a suction valve assembly, and a discharge valve assembly for selectively communicating suction and discharge lines with the compressor cylinder. An unloader valve assembly including a valve seat structure, valve guard, and multiple poppet valve members is provided to allow selective communication between the compressor cylinder and a clearance bottle. The opening and closing of the unloader valve assembly is controlled by manipulating a control pressure acting through a manifold against the stem ends of the poppet valve members by means of a pressure regulator connected in series with a pressure source. When the pressure in the compressor cylinder acting on the heads of the poppet valve members exceeds the control pressure acting on the stems, the poppet valve members open, partially unloading the compressor.

Abstract: An unloader system is provided for a gas compressor including a cylinder, a piston reciprocably mounted in the cylinder, a crankshaft connected to the piston and suction and discharge valve assemblies, selectively communicating the cylinder with suction and discharge lines. The compressor crankshaft is driven by a prime mover. The unloader system includes an unloader valve assembly, which can comprise one of the suction or discharge valve assemblies, and an unloader actuation system including a controller and a stepper motor. The unloader valve assembly includes a valve seat with a plurality of seat passages arrayed in a seat passage circle. The unloader actuation system rotates an unloader valve assembly guard and valve members mounted thereon in increments corresponding to the radial spacing of the valve members and the seat passages, with each incremental rotation corresponding to a single crankshaft revolution.

Abstract: A suction valve for a gas compressor includes a cylindrical valve guide cage with plurality of rows of valve guides, each with a corresponding poppet valve slidably movable therein. Each valve guide communicates with a compressor cylinder. A concentric cylindrical valve seat chair with a like plurality of rows of valve seats surrounds the valve guide cage. Each valve seat communicates with a suction chamber. A plurality of openings extending through the guide cage are spaced between the rows of valve guides. To unload the compressor, the valve guide cage is movable relative to the valve seat chair, thus unseating the poppet valves and effectively opening the compressor cylinder to the suction chamber. A first embodiment uses a pneumatic cylinder to move the valve guide cage longitudinally while a second embodiment uses a rotary crank to move the valve guide cage rotationally.

Abstract: A valve assembly is provided which includes a seat structure and a cage structure. A valve member is movable between open and closed positions and includes an upstream side adapted to engage the seat structure with the valve member in its closed position and a downstream side connected to the cage struture. The cage structure includes a manifold communicating with the valve member downstream side. A pilot valve is provided for selectively venting the manifold to an area of low fluid pressure whereby the valve member is held in its open position.