Patent Application
20130240051
Flapper valve assemblies are ubiquitous in the downhole drilling and completions industry, e.g., for use in subsurface safety valve systems among others. These valves include a flapper or lid that closes against a seat for forming a seal. Leaking may occur through these valves if the flapper and the seat are misaligned, particularly at low pressures when the flapper is not pressed firmly against the seat. One cause of this misalignment results from the summation or stack-up of the tolerances of the components of the valve assembly. That is, a complex arrangement like a flapper valve assembly has many components, and while the effect of the tolerances of any individual component is essentially negligible, the sum of all tolerances can result in undesired variances for the assembly as a whole. Accordingly, the industry would well receive systems for improving the performance of flapper valve assemblies.
A valve assembly, including a seat; a flapper complementarily formed with respect to the seat for creating a seal at an interface therebetween; and at least one shim operatively disposed in the valve assembly for altering a position of the flapper relative to the seat in at least one direction for aligning the flapper and the seat at the interface.
A method of aligning a flapper and a seat of a valve assembly, including positioning at least one shim in the valve assembly for altering a position of the flapper relative to the seat in at least one direction.
The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:
A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.
Referring now to the drawings, a valve assembly 10 is shown in
The flapper 14 is hingedly or rotatably secured to the base 12, e.g., via a connection 17, e.g., including a pin, pivot, hinge, etc. In this way, the flapper 14 is rotatable in order to selectively engage against the seat member 16 at an interface 18. The interface 18 is formed by a surface or surfaces, e.g., a contoured surface as illustrated, of the seat member 16 that creates a seal when engaged by the flapper 14. When the flapper 14 and the seat member 16 are properly aligned and engaged at the interface 18, i.e., the valve 10 is in a closed configuration, the flow of fluid through the valve assembly 10 is prevented. It is noted that the flapper 14 and the seat member 16 are complementarily formed such that the interface 18 is undulating or curved, e.g., sinusoidally, although other styles of valves are similarly benefited by the current invention, e.g., flat interfaces as discussed below with respect to
Advantageously, in order to accommodate for, counteract, and/or remedy any misalignment between the components of the valve assembly 10, namely between the flapper 14 and the seat member 16, one or more shims are included. Specifically, the valve assembly 10 includes a longitudinal or axial alignment shim 20 (the “longitudinal shim 20”) and a pair of rotational alignment shims 22a and 22b (the “rotational shims 22a and 22b” or collectively the “rotational shims 22”). For example, in the illustrated embodiment, the position of the flapper 14 with respect to the seat member 16, and therefore the accuracy of alignment between the flapper 14 and the seat member 16 at the interface 18 is influenced by the tolerances used in manufacturing the base 12, the flapper 14, the seat member 16, the connection 17, etc. Accordingly, if the flapper 14 and the seat member 16 are not accurately aligned or matched at the interface 18, then the shims 20, 22 can be utilized as needed for setting the position of the flapper 14 relative to the seat member 16. Since the flapper 14 is connected to the base 12, the shims 20, 22 in the illustrated embodiment are located between the base 12 and the seat member 16 (e.g., for convenience in manufacturing and/or assembly), although it is to be appreciated that any other location that alters the position of the flapper 14 relative to the seat member 16 could alternatively be utilized in other embodiments. The shim 20 substantially resembles a C-shaped ring, while the shims 22 resemble relatively thin, polygonal plates.
As shown in more detail in
The rotational shims 22a and 22b respectively have thicknesses t2 and t3, as shown in
In order to assist in the manufacture of the valve assembly 10, a window 28, or a plurality thereof, are provided in the base 12 for enabling visual inspection of the interface 18 once the valve assembly 10 has been assembled. By providing the windows 28 at intervals circumferentially about the base 12, as shown, significant portions of the interface 18 can be inspected. In one embodiment, visual inspection is assisted by positioning a light source within the valve assembly 10 and observing or measuring the amount of light that shines through the interface 18 and is visible at the windows 28 when the flapper 14 and the seat member 16 are engaged in a low pressure situation, e.g., held closed only by gravity.
A valve assembly 50 according to another embodiment herein is illustrated in
While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.
