Check valve with reduced hold-open pressure

• US 4,989,635 A
• Filed: 11/13/1989
• Issued: 02/05/1991
• Est. Priority Date: 11/13/1989
• Status: Expired due to Term

• Current Assignee: Core Industries Incorporated (SPX Corporation)
• Original Assignee: CMB Industries Inc. (SPX Corporation)
• Inventors: Dunmire, Charles W.
• Primary Examiner(s): RIVELL, JOHN A
• Application Number:
  US07/435,870
• Time in Patent Office: 449 Days
• Field of Search: 137/527, 137/527.2, 137/527.4, 137/512, 251/303, 251/337
• US Class Current: 137/527
• CPC Class Codes: F16K 15/033 spring-loaded
• CPC Class Codes: F16K 2200/204 in series
• CPC Class Codes: Y10T 137/7838 Plural
• CPC Class Codes: Y10T 137/7898 Pivoted valves

Abstract

A check valve with a reduced hold-open pressure includes a biasing device, such as a spring, directly connected to a pivoting clapper at one end and to the valve body at the other end. No intervening pivoting links are used between the spring and the clapper. Preferably, the clapper is connected only by being pivoted to the valve body and by the spring connecting it to the valve body.

Claims

1. A check valve, comprising:

a valve body having at least first and second ports, one of said ports being an inlet port and the other of said ports being an outlet port;

a valve seat adjacent to said first port;

a clapper configured to sealingly mate with said valve seat, said clapper pivotally attached to said valve seat to pivot about a first axis between a first position, wherein said clapper sealingly mates with said valve seat and at least a second position spaced from said valve seat;

first means for biasing said clapper in a direction toward said first position, said means for biasing having a first end and a second end, and forming a compressible connection between said clapper in said first position and said valve body;

second means, adjacent said first end, for attaching said means for biasing to said valve body at an attachment point; and

third means, adjacent said second end, for pivotally attaching said means for biasing to said clapper to permit pivoting of said means for biasing with respect to said clapper about a second axis, wherein the position of said second axis, with respect to said clapper and with respect to said second end, remains fixed during movement of said clapper from said first position to second position.

2. A check valve, as claimed in claim 1, wherein said second means pivotally attaches said means for biasing to said valve body to permit pivoting of said means for biasing about a third axis.

3. A check valve, as claimed in claim 1, wherein said means for biasing is directly attached to said clapper, in the absence of an intervening toggling linkage which pivots with respect to said clapper.

4. A check valve, as claimed in claim 1, wherein said first means includes first and second helical spring sections joined end-to-end by connection to a plate.

5. A check valve, as claimed in claim 1, wherein said clapper is connected to said valve body only by said pivotal attachment about said first axis and by said means for biasing, without rigid links connecting said clapper to said valve body which pivot with respect to said clapper.

6. A check valve, comprising:

a valve body having at least first and second ports, one of said ports being an inlet port and the other of said ports being an outlet port, defining a downstream flow direction for flow through said valve;

a valve seat adjacent to said first port;

a rigid clapper device configured to sealingly mate with said valve seat, said clapper device pivotally attached adjacent to said valve seat to pivot about a first axis between a first position, wherein said clapper device sealingly mates with said valve seat and at least a second position spaced from said valve seat wherein said first and second ports are in fluid communication;

compressional spring means providing a force having a component which biases said clapper device in a direction toward said first position, said means for biasing providing said force along a first longitudinal spring axis definable with respect to a first spring end and a second spring end;

means, adjacent said first end, for attaching said means for biasing to said valve body at a first attachment point; and

means, adjacent said second end, for pivotally attaching said means for biasing to permit pivoting of said means for biasing with respect to said clapper device about a second axis, said spring force being directed along a line passing through said first attachment point and said second axis substantially without a lateral force component.

7. A check valve, as claimed in claim 6, wherein said clapper device includes a disk and an arm rigidly attached to said disk.

8. A check valve, comprising:

a valve body having an inlet port and an outlet port;

an annular valve seat adjacent to said inlet port;

a disk-shaped clapper configured to sealingly mate with said annular valve seat;

an arm rigidly attached to said clapper having a first end and a second end, said first end being pivotally attached adjacent to said inlet port to permit pivoting of said clapper about a first axis from a first position sealingly mating with said valve seat to a second position spaced from said valve seat to permit fluid flow through said inlet port; and

a helical compression spring having first and second spring ends, said first spring end pivotally attached to said valve body to permit pivoting of said spring about a second axis, said second spring end directly pivotally attached to said second end of said arm, to permit pivoting of said spring with respect to a third axis said spring producing a force along a first longitudinal spring axis definable with respect to said first spring end and said second spring end, said force having a closing component which biases said clapper to move in a direction toward said first position, said force being direct along a line passing through said second axis and said third axis substantially without a lateral force component in any clapper position, said closing component being greater when said clapper is in said first position than when said clapper is in said second position.

9. A check valving device, as claimed in claim 8, further comprising:

a second valve seat positioned in said valve body downstream from said first valve seat;

a second clapper attached to move from a first position sealingly mating with said valve seat to a second open position; and

means for biasing said second clapper in a direction toward said first position.

10. A method for check valving flow through a conduit, comprising:

providing a valve body having an inlet port and an outlet port with a valve seat adjacent to said inlet port;

pivotally attaching a clapper device adjacent to said inlet port to pivot about a first axis between a first position sealingly mating with said valve seat and a second position spaced from said valve seat;

providing a spring having first and second ends;

pivotally attaching said first spring end to said valve body to pivot about a second axis; and

pivotally attaching said second spring end directly to said clapper device in the absence of an intervening linkage which pivots with respect to said clapper.