The present invention is directed to a check valve. The check valve is designed with features and materials which limit wear associated with abrasive fluids used in oil and gas operations.
The present invention is directed to a valve. The valve comprises a body, a hinge pin and a flapper. The body has a flow passage interrupted by a chamber at a first opening. The body defines a shoulder face disposed about the first opening in a first direction. The hinge pin is supported by the body. The flapper is attached to the hinge pin and disposed within the chamber. The flapper is movable between a first and a second position. The flapper has a closing face. The closing face comprises a flat peripheral surface conforming to the shoulder face and a surface feature. The peripheral surface abuts the shoulder face when the flapper is in the first position and the surface feature is surrounded by the flat peripheral surface.
In another embodiment, the invention is directed to a valve flapper. The flapper has a first side and a second side. The flapper comprises a closing face, a weighted protrusion, and an eye. The closing face is disposed on the first side. The closing face comprises a planar peripheral rim and a non-planar surface feature contiguous with and extending from the planar peripheral rim. The weighted protrusion is disposed on the second side. The eye has an eye axis parallel to a plane including the planar peripheral rim.
With reference to the Figures, a check valve is shown therein. Check valves may be utilized in oil and gas operations to control flow direction upstream from the valve by “checking” or stopping flow through the valve element when downstream flow direction reverses. The downstream flow direction could reverse due to a high pressure condition or an increase in fluid in the system downstream due to hydraulic fracturing or other oil and gas operations. Equipment, such as pumps, that are upstream of the check valve could suffer damage if flow were to try to reverse.
With reference to
The flapper 16 may be located at an opening 33 where the inlet 12 is interrupted by the central chamber 13. When fluid is flowing in direction d, the flapper is in a raised position as shown in
However, when fluid flow stops, or reverses to flow from the outlet 14 to the inlet 12, the flapper 16 pivots about a hinge 15 to obstruct fluid flow as shown in
The flapper 16 has a first side and a second side. The first side has an inner face, or sealing face 17. The flapper 16, or its sealing face 17, may be economically subjected to hardening techniques, such as heat treatment and tungsten carbide coating. The valve body 11, conversely, may be difficult to so treat. One such technique for hardening is the addition of a coating through a high-velocity oxygen fuel spray process. Alternatively, the flapper 16 or its sealing face 17 may be made from solid carbide, boronized material, or other hardened material.
As shown, the port 19 is closed by threading the cleanout nut 18 to the valve 100 body. The cleanout port 19 allows access to the valve body 11 and the central chamber 13 for routine maintenance, inspection of valve components, and replacement and repair of components. The cleanout port 19 may define a recess for placement of the flapper 16 when in the raised position. The nut 18 may be surrounded by one or more port seals 21.
A halo insert 100, also shown in
A tapered seat 20 is positioned within the check valve 10 proximate the fluid inlet 12. An external profile of the tapered seat 20 preferably conforms to an internally disposed tapered wall 22 of the check valve. The taper of the seat 20 and wall 22 coordinate to open the inlet 12 from a smaller diameter distant from the central chamber 13 to a larger diameter near the central chamber 13. Because the inlet channel 12 tapers away from the central chamber 13, the seat 20 may be press-fit within that channel. Access to the seat 20, as required for installation, replacement and maintenance, is provided by the port 19.
An insert seal may be disposed between the tapered wall 22 and tapered seat 20 to prevent fluid flow between the wall and seat. The insert seal (not shown) may be an O-ring or other seal.
A flapper seal 30 is installed on the tapered seat 20. The flapper seal 30 is preferably installed on a shoulder face 31 of the tapered seat 20. The shoulder faces the downstream side of the valve 10. The shoulder face 31 is disposed about the opening 33. The flapper seal 30 is preferably made of an elastomeric material of high resiliency and tensile strength. When the flapper 16 is closed, the seal 30 blocks upstream fluid flow. Repeated contact between the flapper seal 30 and sealing face 17 will wear the sealing face rather than components of the valve body 11.
With reference now to
A raised surface feature 60 is disposed on the front side 58. The raised surface feature 60 directs particulates in fluid traveling through the valve 10 away from the sealing face 17. This increases the life of the flapper 16 and delays leakage due to erosion.
As best shown in
As best shown in
The contact face 62 both minimizes pressure required to open the flapper and directs abrasive fluid away from the peripheral rim of the sealing face 17. As shown, the contact face 62 is planar, though a concave surface may also be utilized.
As best shown in
The back side 56 of the flapper 16 carries a protruding ballast or weight. The protrusion biases the flapper 16 into the closed position due to gravity. Because of this bias, the flapper closes when flow stops or is reversed. As shown, the weighted protrusion is cylindrical.
With reference to
The bearing 80 may be made with or coated with tungsten carbide or other hardening materials. Use of one or more bearings 80 between the eye 104 and the hinge pin 102 can reduce the wear on both. The hinge pin 102 may be press fit into the bearing 80 to limit relative rotation within the valve 10. Alternatively, the hinge pin 102 may fit loosely within the bearing 80, or the bearing may be provided with internally facing splines (not shown) that interface with the hinge pin 102. In such arrangements, pin 102 and bearings 80 may be hardened to reduce the wear on the pieces due to relative movement.
Reducing wear by hardening hinge elements and using the bearings 80 will prevent the flapper 16 from “dropping” within the check valve 10, causing misalignment between the flapper 16 and the opening 33.
With reference now to
The insert 40 has an insert flapper seal 46 formed on an internally disposed insert shoulder face 48. The flapper seal 46 seals against the sealing face 17 of the flapper 16 as in the embodiment of
Changes may be made in the construction, operation and arrangement of the various parts, elements, steps and procedures described herein without departing from the spirit and scope of the invention as described in the following claims.
Number | Date | Country | |
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62462006 | Feb 2017 | US |