GATE VALVE CAVITY REDUCER

A gate valve cavity reducer comprising a cavity reducer with an outer surface, a channel having an inner surface, and a plurality of bores extending through the cavity reducer body. Each of the plurality of bores extend radially from the inner surface of the cavity reducer to the outer surface of the cavity reducer. The cavity reducer is configured to be removed or inserted into a gate valve.

TECHNICAL FIELD

The present disclosure relates generally to gate valves, and more particularly, to the operation and maintenance thereof.

BACKGROUND

A gate valve is generally used to regulate fluid flow through a central bore within the body of the valve. The gate valve is a movable component that will either allow fluid flow or obstruct fluid flow. When the gate valve is fully open, fluid is allowed to travel through the bore. When the gate valve is closed, the fluid flow is obstructed. To ensure that flow is obstructed, gate valves generally include a seat which contacts the gate and forms a seal to prevent fluid from leaking out of the central bore when the valve is in the closed position.

As the gate valve moves between the open position and the closed position, this movement results in wear on the valve, particularly at the point where the seat contacts the gate. To minimize this wear and aid in ease of operation, the area around the gate, also sometimes referred to as the valve cavity, is often filled with a lubricant such as grease.

Due to the configuration of gate valves, they generally include a cavity that is significantly larger than other types of valves, such as ball valves or plug valves. As a result, there are significant costs associated with filling the entire cavity of a gate valve with grease. In addition to the initial cost of the grease required to fill the cavity, grease becomes contaminated by various substances while the valve is in use. Disposing of contaminated grease can be quite expensive, nearly as much as the cost of new grease. Contaminated grease also often includes hazardous substances that require special handling and pose potential risks to the environment.

Certain prior art devices have proposed solutions to address the volume of grease needed. However, these solutions have either narrowly reduced the amount of grease needed or created additional issues such as making the gate valve less accessible for service.

Therefore, what is needed is an apparatus, system or method that addresses one or more of the foregoing issues, among one or more other issues.

SUMMARY

A gate valve cavity reducer may comprise a body with an outer surface, a channel having an inner surface, and a plurality of bores extending through the body. Each of the plurality of bores extend radially from the inner surface of the cavity reducer to the outer surface of the cavity reducer. The cavity reducer is configured to be removed or inserted into a gate valve.

A gate valve comprising a valve body, a valve element disposed within the valve body volume so that the valve element is movable, and a cavity reducer disposed within the valve body volume. The cavity reducer defines a channel to permit movement of the valve element. The cavity reducer includes a plurality of bores extending radially from the channel of the cavity reducer body to an outer surface of the cavity reducer body. In some embodiments, the cavity reducer body includes an upper cavity reducer and a lower cavity reducer.

DETAILED DESCRIPTION

The present disclosure relates generally to gate valves, and more particularly, to the operation and maintenance thereof. As described herein, embodiments of the gate valve described herein address certain issues described above with respect to traditional gate valve configurations.

FIG.1provides a cross-sectional side view of a gate valve10with a cavity reducer22, in accordance with embodiments of the present disclosure. The gate valve10controls the flow of fluid and is operated to selectively block the flow of fluid.

The gate valve10includes a valve body12which intersects a flow passage14. The flow passage14includes central longitudinal axis A and comprises a throughbore, such that fluid is allowed to flow entirely through valve body12, as long as the valve is not in the closed position, as discussed further below. A person of skill in the art would understand that fluid could flow through the flow passage14in either direction.

The valve body12includes a chamber32, which includes central vertical axis B and comprises an upper portion32A, which is generally adjacent to actuator20that is used to open and close the valve, and lower portion32B. Cavity32intersects flow passage14is oriented such that central vertical axis B is substantially perpendicular to central longitudinal axis A of flow passage14.

Gate16is disposed within cavity32, and also comprises upper portion16A disposed within upper portion32A of the chamber and lower portion16B disposed within lower potion32B of the chamber. A person of ordinary skill would understand that the gate16could be replaced by a different flow barrier, such as a plug.

The gate16intersects the flow passage14at a valve seat28. Valve seat28forms a seal with the surface of gate16to prevent fluid in flow passage14from passing into chamber32. Due to that engagement, opening and closing of the valve results in friction between gate16and valve seat28. Such friction can result in wear on valve seat28, as well as an increase in the amount of force required to open and close the valve. To reduce such friction, a lubricant such as grease is often used at the interface between valve seat28and gate16. Grease is often disposed at the interface between valve seat28and gate16by simply filling cavity32with grease. This approach can be expensive and inefficient, given the cost of grease. In addition, as noted above, grease within cavity32will become contaminated over time, which requires expensive and environmentally hazardous removal and disposal.

As shown inFIG.1, a cavity reducer22can be disposed within cavity32of the gate valve10. The cavity reducer22can reduce the amount of grease needed by displacing the volume within cavity32. In some embodiments, the cavity reducer22is custom designed to fit within the existing cavity32of a gate valve10. In some embodiments, the gate valve10already includes a cavity reducer22. In the illustrated embodiment, the cavity reducer22includes an upper cavity reducer24disposed within upper portion32A of the chamber and a lower cavity reducer26disposed within lower portion32B.

FIG.2is a cross-sectional side view of the upper half of the cavity reducer24, in accordance with embodiments of the present disclosure. In some embodiments, the upper cavity reducer24is inserted into cavity32above the seat28. The upper cavity reducer24includes a central channel formed so that gate16can move along the channel. Embodiment can also include spacer41to assist in channel gap opening. In this embodiment, the upper cavity reducer24also serves as a guide for gate16as it moves between the open position and the closed position.

FIG.3is a cross-sectional side view of the upper cavity reducer24, in accordance with embodiments of the present disclosure. An insert removal tool45may be used to remove and reinsert the upper cavity reducer24into cavity32. The insert removal tool is fastened to the cavity reducer22via a bolt49that is disposed within a bore47in the insert removal tool45.

FIG.4is a cross-sectional side view of the lower cavity reducer26, in accordance with embodiments of the present disclosure.FIG.5is a cross-sectional view of the lower cavity reducer26, in accordance with embodiments of the present disclosure. With reference toFIGS.5and6, in some embodiments, the lower cavity reducer26is inserted into cavity32below the seat28. The lower cavity reducer26includes a central channel formed by a support63so that gate16can move vertically to engage with the seat28. In this embodiment, the lower cavity reducer26also serves as a guide for gate16as it moves between the open position and the closed position.

In some embodiments, the cavity reducer22can include one or more passages to allow for movement of grease or other lubricant within cavity32during operation of the gate valve. In some embodiments, the cavity reducer22includes a plurality of bores30such that a lubricant in cavity32can pass through cavity reducer22and lubricate the interface between gate16and seat28. The grease within the cavity32does not prohibit the operation of the gate16as it moves between the open and closed position.

FIG.6is a top view of the lower cavity reducer26, in accordance with embodiments of the present disclosure. In some embodiments, cavity reducer22is placed within the cavity32of the valve body12, which conventionally is filled with grease. By inserting the cavity reducer22, grease in the volume of the cavity32is displaced into an annulus71formed or defined between an outer surface38of the cavity reducer22and an inner surface or wall40of the cavity32.

In some embodiments, the plurality of bores30are in a radial arrangement and are oriented substantially parallel to central longitudinal axis A of flow passage14. In the illustrated embodiment, each bore30extends radially outward from central vertical axis B of cavity32towards the annulus between cavity reducer22and wall40of cavity32. As illustrated, a portion of the plurality of bores extend perpendicularly outward from an inner surface42of a central channel36. In some embodiments, a portion of the plurality of bores30extend at an acute angle relative to an inner surface42of the central channel36. In some embodiments, each bore30has a circular cross-sectional profile extending radially or a tubular shape. In the illustrated embodiment, the plurality of bores are axially spaced equidistant from other bores. A person of skill in the art would understand that the plurality of bores could be arranged in a different configuration, such as a staggered arrangement.

A person of skill in the art would understand that the amount of grease disposed in the volume of the plurality of the bores can be greater than the amount of grease disposed between the cavity reducer22and a wall of the axial channel40.

The number and size of bores30may be selected based on the volume of grease within cavity32after the insertion of cavity reducer22and gate16. In particular, there will be a portion of remaining volume (V3) within cavity32and an additional volume (V2) of the annulus71between cavity reducer22and wall40of cavity32. This total volume (V2+V3) within cavity32will be filled with grease. The plurality of bores30will collectively have a volume (V1), which provides a pathway for the grease, ensuring that a certain portion of the total volume of grease V2+V3remains deployable. For example, it may be considered desirable for at least ⅓ of the total volume of grease to remain deployable, such that V1≥⅓(V2+V3).

The upper cavity reducer24and the lower cavity reducer26may be manufactured using a molding process. In some embodiments, a NYCAST® NYLOIL Type 6 Oil Filled Nylon material is used. A person of skill in the art would understand that any non-metallic, castable, and machinable material could be used. The material for the cavity reducer22may be poured into a cast to form the diameter and length of the cavity reducer22. The upper cavity reducer24may be two separate parts made from the same cast blank. The lower cavity reducer26may be formed in a single cast. The molds may then be placed in a multi-axis machine which will turn the external profiles. Bores may then be drilled into the mold of the cavity reducer in the arrangement as determined based on the volume discussion above. In some embodiments, the cavity reducer components are also milled.

It is understood that variations may be made in the foregoing without departing from the scope of the present disclosure. In several exemplary embodiments, the elements and teachings of the various illustrative exemplary embodiments may be combined in whole or in part in some or all of the illustrative exemplary embodiments. In addition, one or more of the elements and teachings of the various illustrative exemplary embodiments may be omitted, at least in part, and/or combined, at least in part, with one or more of the other elements and teachings of the various illustrative embodiments.

Although several exemplary embodiments have been described in detail above, the embodiments described are exemplary only and are not limiting, and those skilled in the art will readily appreciate that many other modifications, changes and/or substitutions are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the present disclosure. Accordingly, all such modifications, changes, and/or substitutions are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, any means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Moreover, it is the express intention of the applicant not to invoke 35 U.S.C. § 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the word “means” together with an associated function.