Check valves

A check valve comprises a valve housing defining a valve opening and a pair of flapper elements pivotably mounted to the valve housing for rotation relative to the housing between an open position in which they permit fluid flow through the valve opening and a closed position in which they prevent fluid flow through the valve opening. Each flapper element comprises at least one bumper element arranged to engage a stop when in the open position, the bumper element comprising an elastically deformable tongue extending from an upper surface of the flapper element.

FOREIGN PRIORITY

This application claims priority to European Patent Application No. 16461509.8 filed Mar. 15, 2016, the entire contents of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to check valves, and check valve flapper elements.

BACKGROUND

It is known to use check valves to allow fluid flow in one direction therethrough, and to prevent flow in the opposite direction. Check valves are widely used in a wide variety of applications, for example in air conditioning systems, for example in aircraft air conditioning systems.

Check valves commonly include a pair of hinged flapper elements that pivot open in the direction of fluid flow when the fluid pressure differential exceeds a predetermined valve “cracking pressure”. If a negative pressure differential exists across the valve, the flapper elements close, preventing flow reversal. Such check valves typically include a pair of flapper elements and frequently employ bumper elements that engage with a stop surface in order to restrict the opening movement of the flapper element past a predetermined maximum opening angle.

The flapper elements of such prior art flapper valves typically open at high velocities, which typically results in relatively large impacts between the bumper elements and the stop surface when the maximum opening angle is reached. This may result in damage to the check valve components, leading to reduced part lifetimes.

The present disclosure relates to a check valve and check valve flapper element which includes a modified bumper element.

SUMMARY

According to the present disclosure, there is provided a check valve comprising a valve housing defining a valve opening and a pair of flapper elements pivotably mounted to the valve housing for rotation relative to the housing between an open position in which they permit fluid flow through the valve opening and a closed position in which they prevent fluid flow through the valve opening. Each flapper element comprises at least one bumper element arranged to engage a stop when in the open position, the bumper element comprising an elastically deformable tongue extending from an upper surface of the flapper element.

A pair of mounting posts may be arranged on opposed sides of the valve opening and a hinge pin is mounted between the mounting posts. The at least one bumper element may be arranged at a side region of the flapper element for engagement with a stop provided on a mounting post.

In another embodiment, a stop surface may be provided on a post extending away from the opening between the mounting posts, and the bumper element be positioned intermediate the sides of the flapper element, for example generally centrally thereof.

In a further embodiment, a stop surface may be formed on a stop pin extending between the mounting posts above the hinge pin, and one or more bumper elements may be provided on the flapper element to engage the stop pin.

According to another aspect of the present disclosure, there is provided a flapper element for a check valve. The flapper element comprises a bumper element for engagement with a stop provided on the check valve. The bumper element comprises an elastically deformable tongue extending from a surface of the flapper element.

A pair of bumper elements may be arranged at opposite side regions of the flapper element.

In other configurations, a bumper element may be arranged generally centrally of the flapper element.

The elastically deformable tongue may comprise a convexly curved upper surface for engaging the stop.

The upper surface may be smoothly curved or facetted.

A groove may be formed between the elastically deformable tongue and the upper surface of said flapper element.

The groove may diverge from a proximal end to a distal end.

The proximal end of the groove may be rounded.

In certain embodiments, the elastically deformable tongue may be formed integrally with the flapper element.

In other embodiments, the elastically deformable tongue may be machined into the flapper element.

The flapper elements may be generally D-shaped.

In certain embodiments, the flapper element may comprise nickel steel.

In other embodiments, the flapper element may comprise an aluminium alloy.

DETAILED DESCRIPTION

With reference toFIGS. 1 to 4, a check valve2in accordance with this disclosure is illustrated. The check valve2is configured to be mounted around its periphery in or to, for example, a duct in order to prevent reverse flow of a fluid through the duct.

The check valve2comprises a valve housing4, in this embodiment formed as a generally planar annular element. The valve housing4comprises a pair of valve openings6which are separated by a central web8of the valve housing4.

A pair of mounting posts10are arranged on opposed sides of the valve housing4and extend upwardly from the valve housing4. The mounting posts10may be integrally formed, for example cast, with the valve housing4. Alternatively, the mounting posts10may be separately formed from the valve housing4and mounted thereto by suitable means, for example by welding, brazing or by suitable fastening means.

A hinge pin12is mounted between the mounting posts10above the central web8of the valve housing4. The hinge pin12may be a unitary structure as shown, or be constituted from two or more sections, for example.

The valve openings6are closed by a pair of generally planar D-shaped flapper elements14which are pivotally mounted to the hinge pin12. Each flapper element14includes a proximal end16and a distal end18and includes one or more mounting lugs20, in this embodiment three mounting lugs20, positioned at its proximal end16. The mounting lugs20have respective bores22through which the hinge pin12extends. The mounting lugs20of the respective flapper elements14alternate along the hinge pin12.

As shown inFIG. 2, the lower surfaces24of the flapper elements14are provided with a plurality of recesses26, for weight saving purposes, although this is not essential.

The flapper elements14are configured to move between an open position and a closed position, permitting or preventing flow through the openings6respectively. It will be appreciated that the arrangement shown inFIG. 3(i.e. where only one flapper element14is in the open position) is simply illustrative, and in practice both flapper elements14will move together. The peripheral region28of the lower surface of each flapper element14engages the flange29surrounding the respective valve housing opening6when the valve2is in the closed position, forming a seal therebetween.

As discussed so far, the construction of the check valve2is conventional.

However, each flapper element14further comprises at pair of bumper elements30at its proximal end. In this embodiment two bumper elements30are arranged at opposite sides of the flapper element14, although it will be appreciated that other bumper element arrangements may fall within the scope of the disclosure.

The bumper elements30are configured to engage respective stop surfaces32formed on the respective mounting posts10when the flapper elements14are in the open position to prevent the flapper elements14from opening beyond a maximum opening angle. The maximum opening angle may be determined based upon the valve design or flow requirements, for example.

The stop surface32in this embodiment is simply formed as a vertical planar surface of the mounting post10.

FIGS. 5 and 6illustrate detailed side and perspective views of the bumper element28. Each bumper element30comprises an elastically deformable tongue34that extends from the upper surface36of the flapper element14, i.e. the surface of the flapper element14facing away from the valve openings6. The elastically deformable tongue34includes a convex upper surface38for engaging the stop surface32of the mounting post10. In this embodiment, the upper surface38comprises a rounded convex surface. In other embodiments, the surface38may, for example be facetted, that is, comprising a number of angled planar or curved surfaces.

The elastically deformable tongue34may be integrally formed, for example cast, with the flapper element14. Alternatively, the elastically deformable tongue34may be machined into the flapper element14.

A groove40is defined between the tongue34and the upper surface36of the flapper element14. In this embodiment, the groove40diverges from a proximal end42to a distal end44. It will be appreciated however, that the groove40may not diverge, but may rather be a slot with parallel edges, for example. As shown inFIGS. 5 and 6, the proximal end42of the groove40is rounded to provide improved stress distribution at the proximal end42of the groove40.

In operation, each of the flapper elements14is configured to move pivotally about the hinge pin12between a closed position and an open position. When the flapper elements14move into the fully open position, the upper surfaces38of the respective elastically deformable tongues34engage with the stop surface32of the respective mounting post10, preventing pivotal movement of each of the respective flapper elements14beyond this position.

The groove40defined between the bumper element30and the upper surface36of the flapper element14permits the tongue34to elastically deflect toward the flapper element14. This elastic deformation of the tongue34dissipates energy as the bumper element30impacts the stop surface32of the mounting post10. Moreover, the convex shape of the upper surface38of the elastically deformable tongue34facilitates relative sliding motion between said bumper elements30and said mounting posts10. The relative sliding motion will also facilitate energy dissipation The bumper design may therefore allow the flapper elements14to open at higher velocities without inflicting damage to the flapper elements14or the mounting posts10, which in turn may improve valve lifespan.

The material chosen to manufacture the flapper and bumper elements14,30will depend on the particular application. For example, in low temperature and/or pressure applications, an aluminium alloy may be a suitable material. For higher temperature and/or temperature applications, a steel, such as a nickel steel (for example Inconel®) or a stainless steel may be appropriate. Similar materials may be used for the valve housing4and mounting posts10.

The figures and the accompanying description above describe a particular embodiment of the disclosure and it will be understood that modifications may be made to the described embodiment without departing from the scope of the disclosure.

For example, although the convex upper surface38of the bumper element30may be advantageous, in other embodiments, the upper surface38may be planar.

Also, the stop may be provided on a different portion of the check valve2. In one alternative embodiment, illustrated inFIG. 8, a stop surface32may be provided on a post50extending upwardly from the central web8. The hinge pin12extends into or through the post50. As illustrated, the post50may be arranged centrally between the mounting posts10. In this embodiment, the bumper element30is be positioned intermediate the sides of the flapper element14, generally centrally thereof at an appropriate spacing from the proximal end16of the flapper element14. The proximal end16of the flapper may include, as shown, a recess52to accommodate the post50. The bumper element30is substantially similar in construction and operation as that of the first embodiment, although it may be wider (in the lateral direction of the flapper element) than the individual flapper elements30of the first embodiment so as to dissipate the contact forces over a similar total surface area.

In a further embodiment, illustrated inFIG. 9, opposed stop surfaces60may be formed on a stop pin62extending between the mounting posts10above the hinge pin12. The bumper elements30are arranged opposite one another on the respective flapper elements14so as to engage the opposed stop surfaces60on the stop pin62. The bumper element30is substantially similar in construction and operation as that of the second embodiment.

These and other modifications are intended to fall within the scope of the disclosure.