Technical Field

This invention generally relates to check valves, and more specifically to an exercisable, biased, nozzle-type check valve having a piston assembly.

Background of the Invention

Valves are conventionally used in a number of applications to control the flow of fluids through piping systems. Traditionally in conventional check valves, including flap-type valves, ball valves, disc valves, and the like, the check valve is configured to allow flow in only one direction through the piping system. Such a check valve may allow fluid flow past the valve closure member in one direction while preventing fluid from flowing in the other direction, for example, toward a compressor or pump. In this way, check valves can be used to protect a compressor, pump, or other component from backwards flow or backwards pressure (backpressure).

In some applications, check valves are biased via a spring or other biasing mechanism. For example, "normally open" valves are biased open, requiring backpressure to close the valve and "normally closed" valves are biased closed, requiring forward pressure to open the valve. When either valve is operating correctly, the valve remains open while fluid is flowing through the valve in a forward direction, from an inlet to an outlet, and if the fluid flow reverses, the valve closes. This prevents flow in an unintended direction.

For both types of check valves, the valve may be installed in a plant or factory where the valve may not require replacement for the life of the plant or factory. However, to ensure safe operating conditions, there may be a desire to verify the operation of the check valve to ensure that the valve properly prevents backwards flow. Further, there may be regulatory requirements requiring periodic verification of proper operation. However, it is difficult or impractical to test a conventional check valve, since testing will often require either inducing backwards flow in the plant or factory or removing the valve, possibly requiring a significant halt in production.

Exercisable check valves do exist for which proper operation may be verified by testing. See, for example, U.S. patent No. 8,701.693.

However, there is a desire in the industry to enhance the ability to exercise a check valve to verify proper operation, such that a continuing need exists for a more efficient method and system to quickly and easily test the operation of a check valve without requiring significant additional clean up and without causing significant generation of waste. Summary of the Invention

Briefly described, the present disclosure generally describes an exercisable check valve having a piston assembly. According to one embodiment, the check valve of the present disclosure includes a valve body having an inlet, an outlet, and a flow passage between and fluidly connecting the inlet and outlet. The check valve also includes a valve closure member, a piston assembly, and a test fluid delivery channel. According to some embodiments, the check valve also includes a biasing element that causes the check valve to be normally biased open. The valve is suitable for use in any conventional piping system, or the like.

In the presence of forward flow, the check valve remains open while fluid flows into the inlet, through the flow passage, and out the outlet, such that fluid may flow through the valve and any associated piping system. In the case of reverse flow or backpressure, the reverse flow or backpressure will cause the valve closure member to engage the valve body to interrupt flow through the check valve. In this way, the check valve only allows flow in one direction.

The piston assembly is used to drive the valve closure member during testing of the valve and includes a piston bore received in a support member within the flow passage and a piston at least partially received in the piston bore. A test fluid delivery channel fluidly connects the exterior of the valve body to the piston bore. To verify proper operation of the check valve, a user applies a source of pressure to the test fluid delivery channel. Application of pressure will cause the piston to move relative to the piston bore, driving the valve closure member and causing the valve closure member to engage the valve body to interrupt fluid flow through the flow passage. A rod may then be inserted through a port in the valve to determine whether the closure member is in the proper closed position. In this way, the valve may be exercised and tested without being removed from a piping system, without inducing significant backwards flow through the piping system, and without significant cleanup.

Various objects, features, and other advantages of the present invention will become apparent to those skilled in the art upon a review of the following detailed description when taken in conjunction with the accompanying drawings.

Brief Description of the Drawings

Fig. 1 is a cross-sectional profile view of an exemplary check valve in an open configuration, according to a first embodiment of this disclosure.

Fig. 2 is a cross-sectional profile view of an exemplary check valve in a closed configuration, according to a first embodiment of this disclosure.

Fig. 3 is a perspective view of an exemplary check valve according to a first embodiment of this disclosure.

9 Fig. 4 is a perspective view of an exemplary check valve with a section of the valve body cut away, in a closed configuration, according to a first embodiment of this disclosure.

Fig. 5 is an end view of an exemplary check valve according to a first embodiment of this disclosure from a perspective taken looking directly into the inlet.

Fig. 6 is an end view of an exemplary check valve according to a first embodiment of this disclosure from a perspective taken looking directly into the outlet.

Fig. 7a is a cross-sectional perspective view of an exemplary check valve in an open configuration, according to a first embodiment of this disclosure.

Fig. 7b is a cross-sectional perspective view of an exemplary check valve in a closed configuration, according to a first embodiment of this disclosure.

Detailed Description of the Invention

Referring now in greater detail to the drawings in which like numerals refer to like parts throughout the several views, Figs. 1 and 2 respectively illustrate one embodiment of an exercisable check valve 10 according to the present disclosure in an open and a closed configuration. However, it will be understood by those skilled in the art that the check valve disclosed herein is suitable for use with any type of piping or tubing system, or the like, including in the piping system of a factory or plant, such as a power plant. The present disclosure thus is not and should not be limited solely for use with a particular type or types of piping or flow delivery system.

Although the following description includes an exemplary check valve and methods that embody the inventive subject matter of this disclosure, it will be understood by a person of ordinary skill in the art that the described subject matter may be practiced with some or all features of the embodiments disclosed herein in various combinations to create various other embodiments not expressly disclosed herein but nonetheless within the scope of this disclosure.

Fig. 1 is a cross-sectional view of a check valve 10 in an open configuration according to an embodiment of the present disclosure. The check valve 10 includes a valve body 20 having an inlet 22, an outlet 24, a flow passage 28 between and fluidly connecting the inlet 22 and outlet 24, and a piston assembly 30. The valve 10 is configured to allow flow into the inlet 22, through the flow passage 28, and out from the outlet 24, and to prevent flow of fluid in the reverse direction, i.e. from the outlet 24 to the inlet 22.

According to the embodiment shown in Figs. 1 and 2, the piston assembly 30 includes a piston bore 32 and a piston 36 at least partially received in the piston bore 32. The piston bore 32 is formed in a downstream support member 42, and the downstream support member 42 is fixed relative to the valve body 20. Still according to the embodiment shown in Figs. 1 and 2, a valve closure member 50 is received in the flow passage 28. The valve closure member 50 is supported in such a way as to be movable between at least an open position in which fluid may flow through the flow passage 28 and a closed position in which the valve closure member 50 cooperates with the valve body 20 (by, for example, sealing at a valve closure seat 26) to interrupt fluid flow through the flow passage 28. The valve closure member 50 is engaged by the piston 36 such that the piston 36 acts to move the valve closure member 50 to the closed position when the piston 36 is moved from a first position to a second position.

According to some embodiments, the piston 36 and valve closure member 50 are coupled so that movement of the piston 36 to and from the first and second positions causes respective movement of the valve closure member 50 to and from the open and closed positions. In some such

embodiments, a biasing element 60 is coupled to either the piston 36 or the valve closure mechanism 50 to respectively bias either the piston 36 to its first position or the valve closure member 50 to its open position.

Fig. 2 depicts a cross-sectional view of a check valve 10 in the closed configuration according to some embodiments. The presence of backwards flow or pressure in the direction from the outlet 24 to the inlet 22 causes the valve closure member 50 to move to the closed position. In the closed position, the valve closure member 50 engages the valve closure seat 26, thus cooperating with the valve body 20 to block fluid flow through the flow passage 28 from the outlet 24 to the inlet 22. This feature is particularly desirable in situations where equipment which could become damaged from reverse flow, such as a pump or compressor, is located upstream from the check valve 10. Further, this feature of preventing reverse flow may be required for compliance with safety regulations.

A fluid delivery test channel 70 fluidly connects the interior of the piston bore 32 with the exterior of the valve body 20. Application of fluid or another pressure source to the fluid delivery test channel 70 causes the piston 36 to move from the first position to the second position which in turn causes the valve closure member 50 to move to the closed position. In this way, the fluid delivery test channel 70 can be used to cause the valve closure member 50 to be in the closed position.

The check valve 10 according to some embodiments further includes additional ports 80, 90 that fluidly connect the exterior of the valve body with the interior of the flow passage. These ports are configured to support inspections as will be understood by those of ordinary skill in the art.

With reference to Figs. 1 and 2, operation of the fluid delivery test channel 70 and piston assembly 30 will now be described according to some embodiments. As previously mentioned, the piston bore 32 is located within the downstream support member 42 and the piston 36 is at least partially received within the piston bore 32. According the embodiment shown in Figs. 1 and 2, the fluid delivery test channel 70 extends from a fluid delivery test channel opening 72 in the valve body, to another fluid delivery test channel opening 74 in the rear portion 34 of the piston bore 32. To test the operation of the valve and to ensure its ability to properly prevent flow in the reverse direction (i.e. from outlet 24 to inlet 22), a source of pressurized fluid (e.g. a liquid), is connected to the valve body fluid delivery test channel opening 72, and the pressurized fluid is introduced through the test channel 70.

The piston assembly 30 (including piston 36 and piston bore 32) is configured in a manner as will be understood by those skilled in the art such that the pressure source causes pressure to build up behind the piston 36 in the rear portion 34 of the piston bore 32, causing a force to act on the piston end 46 sufficient to move the piston 36 from the first position to the second position, in turn causing the valve closure member 50 to move to the closed position.

According to the embodiment of Figs. 1 and 2, the biasing element 60 is a spring 60 mounted on the upstream side of the closure member 50 and supported as to assert pressure against the closure member 50 for normally biasing the valve closure member 50 to its open position. According to some embodiments, the biasing element 60 is supported on an upstream end by an upstream support member 44 that is fixed relative to the valve body 20, and the biasing element 60 exerts pressure against the closure member 50 and the upstream support member 44 to bias the closure member 50 to the open position.

As previously described, in some embodiments, such as shown in Figs. 1 and 2, the piston 36 and valve closure member 50 are coupled such that when the piston 36 is in the first position, the valve closure member 50 is in the open position and when the piston 36 is in the second position, the valve closure member 50 is in the closed position. In such embodiments where the piston 36 and valve closure member 50 are coupled, it is only necessary to bias one of the valve closure member 50 and the piston 36, since the other will be biased as a result of the piston 36 and valve closure member 50 being coupled.

According to the embodiment of Fig 1 and 2, the coupling is in the form of rigid attachment, such as welding or forging as one component. Other forms of coupling are also acceptable, such as but not limited to hinging, linking, or the like.

As understood in the art, the piston 36 is configured such that a small amount of pressure in the piston bore 32 is sufficient to overcome the biasing force of the biasing element 60 to cause the piston 36 to move from the first position to the second position. It will be appreciated that the piston bore 32, piston 36, and biasing element 60 may be calibrated such that a predetermined amount of pressure is sufficient to overcome the biasing force of the biasing element 60. In this way , a user may calibrate the sensitivity of the check valve to backwards flow and/or test conditions.

Referring again to Figs. 1 and 2, the biasing member 60 is a compression spring. The compression spring is calibrated such that the presence of a predetermined amount of backwards flow or backwards pressure will cause the valve closure member 50 to overcome the spring force and move to the closed position. The valve closure member 50 of the embodiment of Figs 1 and 2 is in the nature of a valve closure disc 50. The piston 36 and valve closure disc 50 are components of a valve closure disc assembly 40 that further includes an upstream shaft portion 38 rigidly mounted to the disc 50 and axially aligned with and on the opposite side of the disc 50 from the piston 36. The upstream support member 44 is mounted inside the flow passage 26. The valve closure disc assembly 40 is slidably supported by and movable relative to the upstream support member 44, and the biasing member 60 is also coupled to the upstream support member 44.

The valve closure disc assembly 40 further includes first shaft end 46 (defined as the free end of the piston (or downstream shaft portion) 36), which extends into and terminates within said piston bore 32, and a second shaft end 48 (defined as the free end of the upstream shaft portion 38) which extends into and terminates within said flow passage 28. The valve closure disc 50 is coupled to the piston 36 between the first and second shaft ends 46, 48. According to some embodiments, the first shaft end 46 is the downstream end of the piston 36 (i.e. the end closer to the outlet 24), and the second shaft end 48 is the upstream end of the piston (i.e. the end closer to the inlet 22).

According to some embodiments, the valve closure disc 50 has a first valve closure disc face

52 facing the outlet 24 and a second valve closure disc face 54 facing the inlet 22. In such embodiments, the presence of backwards flow or backwards pressure causes a force to be applied to the first disc face 52. When sufficient force on the first disc face 52 is present, the disc will be moved to the closed position in which the second face 54 of the disc 50 will mate with the valve closure disc seat 26 to interrupt flow through the flow passage 28. According to some embodiments, the upstream support member 44 is positioned between the valve closure disc 50 and the second shaft end 48.

It will be understood by those skilled in the art that while the present invention has been disclosed with reference to specific embodiments as described, above, various additional, deletions, modifications and changes can be made thereto without departing from the spirit and scope of the present invention. It will also be understood that the various embodiments and/or features thereof can be combined to form additional embodiments of the present invention.