Clamping of the plug tip in a control valve

Abstract

A plug assembly configured to secure a plug tip to a valve stem. These configurations may include a clamp that secures to the end of the valve stem. The clamp surrounds at least a portion of the plug tip. In one implementation, the design may also include a spring assembly that creates a preload on the top of the plug tip. The clamp is useful because it accommodates plug tips made from brittle materials such as ceramics. The feature can prevent certain mechanical failures, such as cracking or breakage that may occur during manufacturing or assembly. As an additional benefit, the device can maintain alignment of the plug tip with the valve stem. This feature can ensure proper engagement with a seat in a flow control device such as a control valve.

Description

Technical Field

[0001] Flow control devices play a major role in many industrial facilities. For example, power plants and industrial processing facilities use different types of flow control devices to manage the flow of materials, typically fluids, throughout an extensive network of pipes, tanks, generators, and other equipment. These devices may include control valves that provide active control of the flow through the exchange of control signals with a central control network. In oil and gas facilities, operators may deploy control valves to control the flow of debris-laden fluids that often flow at high temperatures and pressures. These conditions are known to rapidly erode the components exposed to the flow. Valve manufacturers may manufacture these components from materials such as ceramics to counter the abrasive effect of the fluid and thereby reduce or delay corrosion or erosion during operation.

Summary of the Invention

[0002] The subject matter of the present disclosure relates to improvements in valve manufacturing or construction that extend the service life of components in these corrosive environments. Particularly interesting are embodiments having a mechanism for securing components within a control valve (or other flow control device). These embodiments can simplify assembly, for example, by eliminating the need to use high torque to tighten or secure components in place. This feature can ensure better alignment, account for the accumulation of tolerances, manufacture components from suitable materials to avoid mismatches due to thermal expansion, or slow the rate at which such components can degrade during operation. Naturally, the fundamental advantage is to reduce the cost of replacing or repairing the device in the field.

Brief Description of the Drawings

[0003] This specification refers to the following drawings. [Figure 1] FIG. 1 shows a schematic view of an exemplary embodiment of a plug assembly 100. [Figure 2] FIG. 2 shows a perspective view of an example of the structure of the plug assembly 100 of FIG. 1. [Figure 3] Figure 3 shows a cross-sectional elevation view of the structure in Figure 2 in its assembled form. [Figure 4] Figure 4 shows a cross-sectional elevation view of an example of the structure shown in Figure 3. [Figure 5] Figure 5 shows a side elevation view of an example of the structure of a flow control device.

[0004] These drawings and any descriptions herein represent examples that may disclose or illustrate the invention. These embodiments include best modes and enable those skilled in the art to carry out the invention, including constructing and using any apparatus or system and performing any incorporated methods. The drawings are not to a constant scale unless the description indicates otherwise. Elements within the embodiments may appear in one or more of several figures, or in combination of several figures. The drawings may use similar reference numerals to indicate identical or corresponding elements. Methods are merely illustrative and may be modified, for example, by rearranging, adding, removing, and / or changing individual steps or stages. In this specification, such steps, as well as any part, component, element, or function, may be identified in the singular using the word “a” or “an.” However, this should not exclude the plural form of such designation unless the specification expressly states or describes such exclusion. References to “one embodiment” or “one implementation” should not exclude the existence of additional embodiments or implementations that also incorporate the enumerated features. [Modes for carrying out the invention]

[0005] Next, the features of the embodiments shown in the drawings above will be described. These examples can utilize ceramics because these materials possess properties well suited for use in flow control devices for corrosive or erosive fluids. For example, ceramic valve components are particularly robust and offer long service lives under conditions (such as high temperature and high pressure) that may be advantageous in oil and gas applications. However, while they exhibit robust properties, components made from these materials are inherently brittle and may break during use or manufacture. The designs herein are intended to address the brittleness of these components. Other embodiments are within the scope of this disclosure.

[0006] Figure 1 shows an example of a plug assembly 100. This embodiment is typically found in a distribution network 102 designed to transport material 104 throughout a network of conduits 106. The plug assembly 100 may also be part of a flow control device 108 having a valve body 110 connected in series with the conduits 106. The device may also have an actuator 112. A valve stem 114 extends from the actuator 112 to position the plug assembly 100 in a fixed position close to the seat 116. In one implementation, the plug assembly 100 may include a plug tip 118 and a clamp 120.

[0007] In general, the plug assembly 100 may be configured for use in highly corrosive flows. These configurations may include devices that can regulate the flow, for example, as part of a valve that regulates the fluid in a process. The design of the device can slow down wear that may occur due to the flow characteristics or dominant conditions in the process (such as high temperature or high pressure). The design can integrate materials such as ceramics that have high resistance to corrosion or erosion. As an additional advantage, the design can incorporate components or features that adapt to the physical properties of these materials, including brittleness that could lead to component damage or failure.

[0008] The distribution system 102 may be configured to deliver or move resources. These configurations can embody extensive infrastructure. The materials 104 may also include gases, liquids, solids, or mixtures. The conduits 106 may often include pipes or pipelines connected to pumps, boilers, etc. The pipes may also be connected to tanks or reservoirs. In many facilities, this equipment forms a complex network.

[0009] The flow control device 108 may be configured to regulate the flow of material 104 through the conduit 106 in this complex network. These configurations may include control valves and similar devices. The valve body 110 in such a device is often made of cast or machined metal. This structure may have flanges formed over the openings I, O. Adjacent pipes 106 may be connected to these flanges. The actuator 112 may use compressed or pressurized air and may generate a load together with a piston, spring (or multiple springs), or flexible diaphragm. The valve stem 114 may form an elongated cylinder or rod that directs this load to regulate the flow of material 104 through the opening of the seat 116.

[0010] The plug tip 118 can be configured to prevent flow through the sheet 116. These configurations may include devices located within the flow path. These devices can be moved relative to the sheet 116. In one implementation, the devices may comprise ceramic(s) or have a surface made of ceramic within the flow path. As described herein, ceramics and similar materials tend to resist erosion and corrosion that coincide with fluid flow, particularly in the hydrocarbon (oil and gas) industry, and this feature can extend the service life.

[0011] The clamp 120 may be configured to receive the plug tip 118. These configurations may include a device that can secure the plug tip 118 to other parts of the valve, including the valve stem 114. The device may employ a mechanism to reduce or avoid stress found in the ceramic tip. This feature can avoid damage that may necessitate repair or replacement of the plug tip within the control valve. These mechanisms can also provide excellent alignment of the plug tip 118 on the valve stem 114, especially at high temperatures of up to 500°C.

[0012] Figure 2 shows an exploded perspective view of an example structure for the plug assembly 100 of Figure 1. This example includes a load assembly 122 that can generate a preload. The load assembly 122 may use a spring 124 for this purpose. A constant-load spring, a conical spring, or a disc spring such as a Belleville washer can provide sufficient force in a package of appropriate size for use in this device. A load-bearing member 126 can be inserted between the spring 124 and the top of the plug tip 118. This part may include one or more flat washers, preferably made of steel or stainless steel, to reduce bearing stress. The washer 126 may be on the top of the plug tip 118 and is shown here having a substantially cylindrical plug body 128 with an upper shoulder 130 having an outer surface 132 with a tapered section 134. The plug body 128 may have a diameter that decreases from the tapered section 134 towards the plug portion 136. The diameter may also preferably vary within the plug portion 136 so as to provide its outer surface 138 with a geometric shape for the plug portion 136 to bond and seal with the sheet 116 (Figure 1).

[0013] The plug assembly 100 may also include components for securing the plug body 128 to the valve stem 114 (Figure 1). These components may include a stem adapter 140 having a boss 142 having a diameter for receiving a spring 124. The boss 142 may terminate at a shoulder 144 that increases in diameter to form a step 146. The stem adapter 140 can then decrease in diameter to form a boss 148. A hole 150 may pass through the top of the stem adapter 140 into the boss 148. The stem adapter 140 may also include a lateral opening 152 perpendicular to the hole 150. As also shown, the plug assembly 100 may include a pair of clamping members 154, 156. These components surround the spring 124 and washer 126 and can secure the plug body 128 to the stem adapter 140. The clamp members 154 and 156 may have a large hole 158 that forms a thin peripheral wall 160 with a lateral opening 162. The large hole 158 may terminate at the bottom wall 164. The central opening 166 may penetrate the bottom wall 164. The central opening 166 on the "lower" clamp member 156 may include a tapered section 168, and its peripheral wall 160 may include a stepped section 170.

[0014] Figure 3 is an elevation view of the assembled structure of Figure 2. The central opening 166 on the "upper" clamp member 154 can be inserted onto the boss 144 of the stem adapter 140. The plug body 128 can be inserted into the central opening 166 of the lower clamp member 156. The peripheral wall 160 on the lower clamp member 156 can be fitted into the large hole 158 on the upper clamp member 154. In one mounting configuration, complementary threads on the peripheral wall 160 allow the technician to screw the clamp members 154 and 156 together until, for example, the stepped portion 170 contacts the step 146 on the shoulder 144 of the stem adapter 142. This design allows the diameters for the shoulder 144 and the large hole 158 on the lower clamp 156 to be either a tight fit or a "sliding" fit. This feature ensures proper alignment of the plug body 128 on the valve stem 114 (Figure 1). The tapered surfaces 132 and 164 form an interface that is also useful for maintaining alignment and controlling the accumulation of tolerances. This interface forms a “conical” contact. In one embodiment, the tapered surfaces 132 and 164 intersect at a conical angle of about 35°, which in response to thermal expansion can push the plug body 128 downward into the central opening 166 of the lower clamp member 156.

[0015] Figure 4 is a cross-sectional elevation view of an example of the structure shown in Figure 3. The valve stem 114 can embody an elongated cylindrical rod 172 having an end 174 that is inserted into a hole 150 in the stem adapter 140. The end 174 may include a lateral opening 176. In one implementation configuration, assembly may require the technician to first place the upper clamp 154 ​​on the stem adapter 140, and then assemble the stem adapter 140 onto the rod 172. A weld 178 can secure the stem adapter 140 onto the rod 172. The weld 178 can completely enclose the diameter of the rod 172. However, other configurations of the welding material may also be prevalent. A first pin 180 can be inserted into the lateral openings 152, 176 to provide further secure engagement of these parts. The technician can then place the spring 124, washer 126, plug body 128, and lower clamp 156. In one embodiment, the load L may be used to compress the spring 124. The technician may use a press (or similar device or fixture) to generate this load. This feature eliminates the need for the technician to apply high torque to screw the clamps 154, 156 together, thereby avoiding twisting or relative movement of the parts which could lead to misalignment between the plug body 128 and the shaft of the rod 172. A second pin 182 may similarly be located within a lateral opening 152 on the clamp members 154, 156. The second pin 182 may extend into the stem adapter 140 to prevent, for example, separation or accidental removal of the clamp members 154, 156 by the technician.

[0016] Figure 5 is an elevation view of an example of the structure of the flow control device 108 of Figure 1. This example includes a valve body 110 made from a casting or forging 184. In one implementation, the casting 184 may have one or more parts, including a flange 186 and a body 188, which are fastened together by a fastener F1. An elongated rod 172 may extend outward from the body 188. A filling flange 190 may be fastened to the upper part 186, for example, using a fastener F2. The filling flange 188 can maintain the position of a specific filling material inside the body 186. The filling material can prevent leakage or transient release that may occur around the elongated rod 172.

[0017] The following examples include specific elements or sections for illustrating embodiments intended within the scope of this specification. These elements may also be combined with other elements and sections to illustrate embodiments. This scope includes and may be conceived of other embodiments that are invented by those skilled in the art. Such other embodiments are within the scope of the claims, for example, if they have structural elements that are no different from the literal wording of the claims, or if they include equivalent structural elements that are little different from the literal wording of the claims.

Claims

1. It is a valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve further comprising a spring assembly disposed in the space between the valve stem-side clamp member and the tip-side clamp member.

2. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve further comprising a spring assembly positioned between the stem adapter and the tip of the plug.

3. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve further comprising a pair of conical springs positioned between the stem adapter and the tip of the plug.

4. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve further comprising a pin extending through the valve stem-side clamping member and the tip-side clamping member.

5. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve further comprising a pin that penetrates the valve stem-side clamping member and extends into the stem adapter.

6. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve wherein the valve stem-side clamp member and the tip-side clamp member engage with each other at a peripheral wall having corresponding threads.

7. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve in which the stem adapter and the tip-side clamp member are in contact with each other.

8. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, On the valve stem side of the aforementioned tip clamp member, a tapered surface is formed where the diameter of the tip side is smaller than the diameter of the valve stem side. A valve in which the tapered surface of the tip-side clamping member and at least a portion of the tip-side surface of the plug tip are in contact with each other.

9. A valve, Valve stem and, A plug assembly coupled to the valve stem, the plug assembly comprising a plug tip and a clamp, the clamp having a stem adapter coupled to one end of the valve stem, and a valve stem-side clamp member and a tip-side clamp member that clamp and secure at least a portion of the plug tip and at least a portion of the stem adapter, A valve in which a welded portion is provided at the portion of the valve stem that contacts the stem adapter, and the stem adapter is fixed to the valve stem by the welded portion.

10. A flow control device, The tip of the ceramic plug, Stem adapter and Spring assembly and, A pair of clamp members, each having an opening, wherein one of the clamp members has a cylindrical portion, and the peripheral wall formed on the inside of the cylindrical portion overlaps with the peripheral wall formed on the side surface of the other clamp member, and the two clamp members are fixed together in this manner. The spring assembly is positioned between the tip of the ceramic plug and the stem adapter. A flow control device comprising: an opening in one of the pair of clamp members that receives the stem adapter, an opening in the other of the pair of clamp members that receives the tip of the ceramic plug, the pair of clamp members being fixed to each other, and the spring assembly biasing the tip of the ceramic plug in the state in which the pair of clamp members are fixed to each other.

11. The flow control device according to claim 10, further comprising a pin extending through each of the pair of clamp members.

12. The flow control device according to claim 10, wherein the peripheral wall of each of the pair of clamp members includes complementary threads in the portion that overlaps with the peripheral wall of the other clamp member.

13. The flow control device according to claim 10, wherein the tip of the ceramic plug and one of the clamp members are in contact with each other and have an inclined surface.

14. The flow control device according to claim 10, wherein the spring assembly generates a preload at the tip of the ceramic plug.

15. The flow control device according to claim 10, further comprising a flat washer disposed between the spring assembly and the tip of the ceramic plug.

16. The flow control device according to claim 10, further comprising an elongated rod having an end that fits into a hole on the stem adapter.

17. A long, slender rod having an end that fits into a hole on the stem adapter, The flow control device according to claim 10, further comprising the stem adapter and a pin extending through the elongated rod.

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