Two-stage flow restrictor valve assembly

• US 4,375,228 A
• Filed: 02/23/1981
• Issued: 03/01/1983
• Est. Priority Date: 02/23/1981
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Original Assignee: General Motors Corporation (Motors Liquidation Co. GUC Trust)
• Inventors: Widdowson, Richard E.
• Primary Examiner(s): Shepperd, John W.
• Application Number:
  US06/237,246
• Time in Patent Office: 736 Days
• Field of Search: 137/503, 62/210, 138/46, 138/45, 138/40
• US Class Current: 138/46
• CPC Class Codes: B60H 1/00485 Valves for air-conditioning devices, e.g. thermostatic valves valves per se F16K; thermostatic valves per se G05D23/02
• CPC Class Codes: F16K 31/363 the fluid acting on a piston F16K31/38 takes precedence
• CPC Class Codes: F16K 47/04 for decreasing pressure or noise level, the throttle being incorporated in the closure member
• CPC Class Codes: F25B 41/30 Expansion means; Dispositions thereof
• CPC Class Codes: Y10T 137/7791 Pressures across flow line valve

Abstract

A two-stage flow restrictor valve assembly is disclosed that is adapted to be inserted in a fluid line to reduce the flow therethrough in two stages. The valve assembly is compactly arranged and comprises a minimum of parts including a valve body, a flow restrictor tube, a power rod, a movable valve assembly operated by the power rod against the spring and a single O-ring for sealing.

Claims

1. A two-stage flow restrictor valve assembly adapted to be inserted in a fluid flow line to reduce the flow therethrough in two stages, said valve assembly comprising a valve body having an inlet side adapted to receive fluid at an upstream point in the line and an outlet side adapted to deliver the fluid at a downstream point in the line, a hollow tube fixed in said valve body between said inlet side and outlet side, said tube having an opening continuously connecting said inlet side through said tube to said outlet side, valve means movable between an open position fully uncovering said opening and an orifice effecting position partially closing said opening to define a small effective orifice of predetermined size, an abutment engaged by said valve means to determine said orifice effecting position, a spring operatively arranged between said tube and valve means normally holding the latter in said open position and resisting movement thereof to said orifice effecting position, said valve means having an upstream side exposed to fluid pressure on said inlet side and passage means communicating this same pressure with a downstream side thereof whereby said sleeve valve means is continuously pressure balanced, a rod engaging with said valve means and extending with substantial annular clearance through said tube so as to be exposed at one end to the fluid pressure on said inlet side and at the opposite end to the fluid pressure on said outlet side while communication between said inlet side and outlet side is maintained through said annular clearance, and said annular clearance defining a large effective orifice of predetermined size substantially larger than said small orifice but smaller than the opening through said tube whereby said valve means is normally held in said open position to effect flow control by said large orifice and is moved to its orifice effecting position to effect flow control by said small orifice at a predetermined pressure differential where the force of the fluid pressure on said inlet side acting on said one end of said rod exceeds the force of said spring and that of the fluid pressure on said outlet side acting in the opposite direction on said opposite end of the rod.

2. A two-stage flow restrictor valve assembly adapted to be inserted in a fluid flow line to reduce the flow therethrough in two stages, said valve assembly comprising a valve body having an inlet side adapted to receive fluid at an upstream point in the line and an outlet side adapted to deliver the fluid at a downstream point in the line, a hollow tube fixed in said valve body between said inlet side and outlet side, said tube having a side opening continuously connecting said inlet side through said tube to said outlet side, sleeve valve means slidably mounted on said tube for movement between an open position fully uncovering said opening and an orifice effecting position partially closing said opening to define a small effective orifice of predetermined size, an abutment engaged by said sleeve valve means to determine said orifice effecting position, a spring operatively arranged between said tube and sleeve valve means normally holding the latter in said open position and resisting movement thereof to said orifice effecting position, said sleeve valve means having an upstream side exposed to fluid pressure on said inlet side and having a side opening communicating this same pressure with a downstream side thereof whereby said sleeve valve means is continuously pressure balanced, a rod engaging with said sleeve valve means and extending therethrough and further extending with substantial annular clearance through said tube so as to be exposed at one end to the fluid pressure on said inlet side and at the opposite end to the fluid pressure on said outlet side while communication between said inlet side and outlet side is maintained through said annular clearance, and said annular clearance defining a large effective orifice of predetermined size substantially larger than said small orifice but smaller than the opening through said tube whereby said sleeve valve means is normally held in said open position to effect a high flow rate range through the line determined by said large orifice and is moved to its orifice effecting position to reduce the fluid flow through the line to a low flow rate range determined by said small orifice at a predetermined pressure differential where the force of the fluid pressure on said inlet side acting on said one end of said rod exceeds the force of said spring and that of the fluid pressure on said outlet side acting in the opposite direction on said opposite end of the rod.

3. A two stage flow restrictor valve assembly adapted to be inserted in a fluid flow line to reduce the flow therethrough in two stages, said valve assembly comprising a valve body having an inlet side adapted to receive fluid at an upstream point in the line and an outlet side adapted to deliver the fluid at a downstream point in the line, a ring seal retained on said valve body adapted to seal said valve body in the fluid flow line between said upstream and downstream side, a hollow tube fixed in said valve body between said inlet side and outlet side, said tube having cross-holes continuously connecting said inlet side through said tube to said outlet side, sleeve valve means slidably mounted on said tube for movement between an open position fully uncovering said cross-holes and an orifice effecting position partially closing said cross-holes to define a small effective orifice of predetermined size, said valve body having an abutment engaged by said sleeve valve means to determine said orifice effecting position, a helical coil spring operatively arranged between said tube and sleeve valve means normally holding the latter in said open position and resisting movement thereof to said orifice effecting position, said sleeve valve means having an upstream side exposed to fluid pressure on said inlet side and having a side opening communicating this same pressure with a downstream side thereof whereby said sleeve valve means is continuously pressure balanced, a rod engaging at an intermediate point along the length thereof with said sleeve valve means and extending therethrough and further extending with substantial annular clearance through said tube so as to be exposed at one end to the fluid pressure on said inlet side and at the opposite end to the fluid pressure on said outlet side while communication between said inlet side and outlet side is maintained through said annular clearance, and said annular clearance defining a large effective orifice of predetermined size substantially larger than said small orifice but smaller than said cross-holes whereby said sleeve valve means is normally held in said open position to effect a high flow rate range through the line determined by said large orifice and is moved to its orifice effecting position to reduce the fluid flow through the line to a low flow rate range determined by said small orifice at a predetermined pressure differential where the force of the fluid pressure on said inlet side acting on said one end of said rod exceeds the force of said spring and that of the fluid pressure on said outlet side acting in the opposite direction on said opposite end of the rod.