MX2007005664A - Ventil - Google Patents

Abstract

A seal assembly for a fluid pressure control device includes a guide element having a sealing surface and a first guide surface. A throttling element assembly includes a throttling element positionable within a fluid flow path, the assembly defining a mating surface adapted to seal with the guide element sealing surface and a second guide surface sized to slidingly engage the first guide surface of the guide element. A relief void is formed in at least one of the guide element and the throttling element assembly adjacent the first and second guide surfaces to receive loose solid material, thereby to prevent disruption of the seal formed between the sealing surface and the mating surface.

Description

SEAL ASSEMBLY FOR A FLUID PRESSURE CONTROL DEVICE Field of the invention The present disclosure relates generally to fluid pressure control apparatus, and more particularly to assemblies for sealing between sliding components used in said apparatus. BACKGROUND OF THE INVENTION Fluid pressure control apparatuses, such as control valve regulators, are commonly used to control the flow characteristics of a fluid. A typical apparatus includes a valve body that defines an inlet, an outlet, and a fluid flow path that extends between the inlet and outlet. A valve seat is attached to the body thereof, and defines a hole through which the flow path travels. A regulating valve element, such as a plug, is movable relative to the valve seat to control the flow of fluid through the orifice. In a slidable spindle fluid control apparatus, the throttle element is coupled to a pin extending away from the valve body, which in turn is coupled to an actuator to position the throttle element to the valve seat. Fluid control devices with a sliding pin often require components to guide the regulator element assembly relative to the valve seat. Particularly, it is desirable to guide the linear movement of the regulating valve member assembly so that it is concentric with respect to the valve cover, seal, housing, seat ring or other component coupled to the valve body. Guide the spike and / or tip of the plug carefully, it also maintains maximum lateral stability to withstand vibration and fatigue failure. Accordingly, the components guiding the movements of the throttle element often include guide surfaces sliding with respect to each other. The friction and sliding of the guide components in the fluid control devices can cause the material of the valve components to come off due to wear, erosion or other causes. The anticorrosive materials used for some applications are particularly susceptible to erosion. Erosion and other wear phenomena can cause the movement and transfer of component material along the contact path. Loose material can degrade or disrupt sealed couplings within the fluid control apparatus, such as the primary seal between the throttle element and the seat, a secondary seal between a regulator element and a housing or a spigot seal between a set of spike and obturator, to mention a few. Conventional approaches to reducing erosion typically employ dissimilar materials for the components that come into contact with one another. This practice can result in higher cost materials and assemblies, and may limit the use of the device in certain applications. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side elevational view, in cross section, of a fluid control apparatus having a relief vacuum positioned adjacent the contact surface between a plug and a seat; Figure 2 is an enlarged view of a detail of the Figure 1, which lustrates the relief vacuum; Figure 3 is a side elevational view, in cross section, of an embodiment of a fluid control apparatus having a relief vacuum located between a plug and a housing; Figure 4 is an enlarged view of a detail of Figure 3 illustrating relief vacuum; and Figure 5 is a side elevational view, in cross section, of another embodiment of a fluid control apparatus having a relief vacuum located adjacent the spike and obturator assembly. DETAILED DESCRIPTION OF THE INVENTION A seal assembly is described for a fluid control apparatus, which includes a relief vacuum to reduce the harmful effects of erosion or other damage caused by wear to sealed contact areas inside the appliance. The relief vacuum provides a space within which the material, typically metallic material, can accumulate from components in contact, thus preventing the material from entering areas destined for sealed contact. For example, the relief vacuum can be positioned adjacent the sealed contact area, between a plug and a valve seat, between a plug and a housing or between a tang and plug assembly. While these exemplary embodiments are described in more detail below, it will be appreciated that the relief void may be located in other areas within a fluid control apparatus that would take advantage of the benefits described herein. Figures 1 and 2 illustrate an unbalanced plug valve with a single-port slide pin (10) having a valve body (12) defining an inlet (14) and an outlet (16), where the valve (10) controls the flow of fluid from the inlet (14) to the outlet (16). A valve seat (18) engages the valve body (12) and defines a hole (20) through which the flow path passes. In the illustrated embodiment, the valve seat (18) is coupled to the valve body (12) by a threaded coupling, however, other coupling methods may be used. An upper part of the valve seat (18) is formed with a sealing surface (22), which has a frusto-conical shape in the exemplary embodiment. A lower part of the valve seat (18) is formed with an inner cylindrical surface (24).

A throttle element assembly (26) is inserted through a port (28) of the valve body to control fluid flow through the valve seat hole (20). The regulating valve element assembly (26) includes a regulating valve element, such as a plug (30), coupled to a spigot (32). The plug (30) includes a matching surface (34) that is formed to complement the sealing surface (22) of the valve seat, such that the matching surface (34) is sealingly coupled to the sealing surface (22) to form a primary seal when the plug (30) is in the closed position, as illustrated in Figure 2. The plug (32) also includes a cylindrical outer surface (36) sized to engage by sliding it to the surface inside (24) of the valve seat. In this embodiment, the inner surface (24) of the valve seat (18) and the outer surface (36) of the plug (30) provide first and second guide surfaces directing the matched surface of the plug (34) toward the surface sealing the valve seat (22) while the regulating valve element assembly (26) moves to the closed position. In the embodiment shown in Figure 1, the cap (30) further includes reeds for flow characterization (38) extending downwardly from the outer surface (36). The rods (38) are formed so that they in turn form gaps (40) therebetween, in order to obtain the desired flow characteristics when the regulator valve element assembly (26) is only partially open, as is well known. He knows in the technique. It will be appreciated that other types of plugs, with and without fluid characterization legs, can be used without departing from the scope of the present disclosure. The pin (32) extends from an upper surface of the plug (30) and through the upper part of the valve body (28). A free end (42) of the spigot (32) is adapted to engage an actuator (not shown) that provides a driving force to the throttle element assembly (26). A valve cap assembly (43) is coupled to the valve body (12) to enclose the upper port (28) and to seal with the pin (32). The valve cover assembly (42) includes a valve cover (44) releasably engaging the body (12), such as by holders. The valve cover (44) has an inner bore (48), which defines a sealing chamber (50) and a neck (52). The neck (52) can be slidably coupled to the spigot (32) to provide additional guidance to the throttle element assembly (26) during movement, as discussed in more detail below, with reference to the embodiment of the Figure 5. A shutter assembly (54) can be inserted into the sealing chamber (50) to seal between the valve stem (32) and the inner bore (48) of the valve cover, to prevent liquid dripping Over there. A relief gap (56) is formed within the seat (18) of the valve to reduce the risk of material released, such as by erosion, from entering the primary sealed area. As illustrated in Figures 1 and 2, the relief vacuum (56) is formed as a groove, generally annular, which creates a gap between the surface (36) of the plug and the inner surface (24) of the valve seat. . The vacuum (56) has a sufficient volume to receive material from the plug (30), the valve seat (18) or other component that can be released or transferred in some other way during the operation of the throttle element assembly (26). ). In the exemplary embodiment, the relief gap (56) is located between the primary seal, formed by the sealing surface (22) and the matching surface (34) and the guide surfaces provided by the outer surface (36) of the stopper, and the inner surface (24) of the valve seat. Accordingly, the material released by erosion, wear or other causes, which will typically originate in the area of the guide surfaces, will accumulate in the relief vacuum (56), thus preventing the interruption of the primary seal. The material deposited in the relief vacuum (56) can be subsequently removed by fluid flow process, or it can remain in the relief vacuum indefinitely. While the exemplary embodiment shows the relief gap (56) located immediately adjacent to the primary seal, it will be appreciated that the relief gap (56) may have other locations, as long as it remains close to either the guide surfaces, or to the sealing surfaces. Moreover, while the relief vacuum (56) is shown as formed in the valve seat (18), it can also, additionally or alternatively, be provided in the plug (30). Accordingly, the same materials or similar materials can be used for the valve seat (18) and the plug (30), such as 316 stainless steel, 304L stainless steel, stainless steel alloy 20, or the like. Figures 3 and 4 illustrate an alternative embodiment of the seal assembly incorporated within the valve (110) having a carcass-like cut, in addition to a balanced plug valve. The valve (110) includes a valve body (112) defining an inlet (114) and an outlet (116), where the valve controls the flow of fluid from the inlet (114) and out the outlet (116). A valve seat (118) engages the body (112) and defines a hole (120) through which the flow path passes. Again, while the valve seat (18) is illustrated as being coupled to the valve body (112) by means of a corded latch, it is possible to use other types of couplings. The seat (118) of the valve includes a sealing surface (122). A regulator valve element assembly (126) and a housing (160) are inserted through an upper port (128) of the valve body (112) to control the flow of fluid through the valve seat bore ( 120). The housing (160) includes a flange (162) which is coupled to it, and substantially closes the upper part of the body (128). A cylindrical wall (164) extends downwardly from the flange (162) and has a lower edge (166) that is spaced apart from the valve seat (118) when assembled, so as to allow fluid flow through the middle. . The cylindrical wall (164) further defines an interior surface (168). The housing (160) also includes a projection (170) having a central bore (172) formed therein. The central perforation (172) is substantially concentric with respect to the inner surface (168) and defines a sealing chamber (150) and a neck (152). The throttle element assembly (126) includes a throttle element that is movable within the fluid flow path. The throttle element, such as a plug (130), is coupled to a pin (132) extending from an upper surface of the plug (130) and through a body upper part of the valve (128) . A free end (142) of the spike (132) is adapted to engage an activator (not shown) that provides a driving force to the regulating valve element assembly (126). A lower part of the plug (130) includes a matching surface (134) that is formed to complement the surface of the valve seat (122), such that the matching surface (134) engages by sealing the sealing surface (122). ) to form a primary seal when the cap (130) is in the closed position. The plug (132) also includes a balance port (133) that allows the fluid to flow into an upper chamber (135) defined by the housing (160) and an upper surface of the plug (130).

The cap (130) includes a guide ring (137) defining an outer surface (136) sized so that when it slides, it engages the inner surface (168) of the housing. In this embodiment, both the guide ring (137) and the inner surface of the housing (168) are cylindrical to provide first and second guide surfaces, adapted to direct the matching surface of the plug (134) toward the sealing surface of the seat valve (122) as the regulating valve element assembly (126) moves to the closed position. The plug (130) also includes a seal ring (139) to prevent fluid dripping through a secondary flow path between the housing (160) and the plug (130). The seal ring (139) is also generally cylindrical and defines a second mating surface (141), dimensioned so that the slide would engage the inner surface (168) of the housing. The seal ring (139) can be formed of a material that is suitably sealed with the metallic material of the housing, while allowing the sliding along the inner surface of the housing (168). Possible materials include a fluorotrated polymer resin, such as the TEFLON® product, marketed by DuPont, a graphite material, or nitrile rubber. A first relief vacuum (156) is formed in the cap (130) to reduce the risk of the free material entering the secondary seal contact area between the seal ring (139) and the interior surface of the housing (168). ). As best illustrated in Figure 4, the relief gap (156) is formed by an intermediate retracted portion (158) of the plug (130). The intermediate retracted part (158) creates a groove, generally annular, that has a sufficient volume to receive material, either from the plug (130), the housing (160), or other valve components that can be loosened or transferred from some another form during the operation of an element set (126). In the illustrated embodiment, the first relief gap (156) is located between the guide ring and the seal ring, however, the alternative locations noted above with respect to the embodiments of Figures 1 and 2 may also be used. To further protect in sealed contact between the seal ring (139) and the inner surface of the housing (168), a second relief vacuum (190) can also be provided. As illustrated in Figures 3 and 4, the second relief vacuum (190) is formed by an upper part (192) of the cap (130) having a reduced diameter. As with the first relief vacuum (156), the second relief vacuum (190) creates a gap between the plug (130) and the interior surface (168) of the housing, which could receive material released by erosion, wear or other causes An additional embodiment of the seal assembly for use in a fluid control apparatus is illustrated in Figure 5, which shows an enlarged, cross-sectional elevated view of a sealed contact between a seal assembly (210) and a tang (211) The spigot (211) is part of a regulating valve element assembly that includes a throttle element (not shown). A valve cover (212) that may be coupled to the valve body (not shown), includes a central bore (214) sized to receive the valve stem (211). The central perforation (214) defines a sealing chamber (218), a neck (220) and a receptacle (222). The obturator assembly (210) can be inserted into the sealing chamber (218) to seal between the valve stem (211) and the inner bore (214), in order to prevent the fluid from flowing in between. The illustrated shutter assembly (210) includes a V-shaped ring (230), a male adapter (232), a female adapter (234), upper ring and lower anti-extrusion ring (236), and a shutter box ring (238), however, other known shutter box components may be used without departing from the present disclosure. In operation, the obturator assembly (210) is compressed such that an inner mating surface (240) of the V-shaped ring (230) engages and seals an outer sealing surface (242) of the spike (211) . The material for the V-shaped ring (230) is selected in such a way that it provides a good seal with the spike, while allowing it to slide. A bearing ring (246) is inserted into the receptacle (222) to subsequently guide the pin (211) during travel. In this way, the bearing ring (246) includes an inner surface (248) that fits perfectly to an outer surface of the spigot (211), but allows the spike to slide. Accordingly, the inner surface (248) and the outer surface of the spigot provide guiding surfaces for directing the sliding movement of the throttle element assembly. A relief gap (250) is formed adjacent to the inner surface (248) to receive the loose material, thereby reducing the risk of degrading the plug / stamper seal assembly. The relief gap (250) is formed as an enlarged diameter portion of the inner surface (248), which creates an annular groove. The groove defines a gap between the inner surfaces of the bearing ring (248) and the outer surface of the pin has a sufficient volume to receive the valve material released during the operation. In this embodiment, the relief gap (250) is located immediately adjacent to the guide surfaces defined by the lower surface (248) of the bearing ring and the outer surface of the spigot, which are slightly separated from the contact sealed between the obturator assembly and the stem. The above detailed description has been provided for clarification and understanding , and no unnecessary limitation should be understood from it, since the modifications would be obvious to those skilled in the art.

Claims (24)

1. An apparatus for fluid pressure control, including: a body defining an inlet, an outlet and a fluid flow path, extending from the inlet to the outlet; a guide element coupled to the body and defining a sealing surface and a first guide surface; and a plug assembly including a plug that is placed within the flow path, and coupled to a pin, the plug assembly defines a matching surface adapted to be sealed with the sealing surface of the guide element, and a second guide surface dimensioned so that the slide would be coupled to the first guide surface of the guide element; characterized in that a relief gap is formed in at least one of the guide elements and the regulating valve element assembly adjacent to the first and second guide surfaces.

2. The fluid pressure control apparatus of claim 1, wherein the relief vacuum is formed as a groove having a volume sufficient to receive the material evolved from a surface of at least one of the plug assembly and the guiding element.

The apparatus for fluid pressure control of claim 1, characterized in that the guide element includes a seat defining the sealing surface and the first guide surface, and in which the plug defines the matching surface and the second guide surface , further characterized in that the matching surface of the plug on the slide engages with the sealing surface of the seat when the plug is in the closed position.

The apparatus for fluid pressure control of claim 3, wherein the relief is positioned adjacent the seat sealing surface and the matching surface of the cap.

The apparatus for fluid pressure control of claim 1, wherein the guide element includes a housing having an interior surface defining the sealing surface and the first guide surface.

The apparatus for fluid pressure control of claim 5, wherein the plug assembly includes a guide ring sized so that when sliding it engages the inner surface of the housing, so as to define the second guide surface, further of a seal ring having an exterior surface dimensioned so that the slide would engage and seal with the interior surface of the housing, in order to define the matching surface.

The apparatus for fluid pressure control of claim 6, wherein a first part retracted from the plug forms the relief vacuum.

8. The fluid pressure control apparatus of claim 7, wherein the first retracted part of the plug is positioned adjacent to the seal ring.

The apparatus for fluid pressure control of claim 7, wherein the first retracted part of the plug is positioned between the guide ring and the seal ring.

10. The fluid pressure control apparatus of claim 8, further including a second relief vacuum formed by a second retracted part of the plug, formed on one side of the seal ring, opposite the first retracted part of the plug.

The apparatus for fluid pressure control of claim 1, wherein the guide element includes a seal assembly defining the sealing surface and the first guide surface, and wherein the spike has an exterior surface that defines the matching surface and the second guide surface.

The apparatus for fluid pressure control of claim 11, wherein the sealing surface and the first guiding surface are defined by a same inner surface of the obturator assembly, and further characterized in that the matching surface and the second surface guide are defined by a same part of the outer surface of the spike.

13. A seal assembly for an apparatus for fluid pressure control having a body defining an inlet, outlet and fluid flow path, extending from the inlet to the outlet, said seal assembly includes: a guide element coupled to the body and defining a sealing surface and a first guide surface; and a set of positionable throttle element within the flow path, said throttle element assembly defining a matched surface adapted to be sealed with the sealing surface of the guide element, and a second guide surface dimensioned so that when it slides it is coupling to the first guide surface of the guide element; further characterized in that a relief gap is formed in at least one of the guide member and the regulator valve assembly adjacent to the first and second guide surfaces.

The seal assembly of claim 13, wherein the relief vacuum is formed as a groove having a sufficient volume to receive material removed from a surface of at least one of the regulating valve element assembly and guiding element.

The seal assembly of claim 13, wherein the guide member includes a seat defining the sealing surface and the first guide surface, further characterized in that the regulating valve element includes a plug defining the matching surface and the second guide surface, characterized in that the coinciding surface of the cap when being slid engages the sealing surface of the seat when the cap is in the closed position.

16. The seal assembly of claim 15, wherein the relief is also located adjacent to the sealing surface of the seat and the matching surface of the cap.

The seal assembly of claim 13, wherein the guide member includes a housing having an interior surface defining the sealing surface and the first guide surface, and further characterized in that the regulating valve element includes a set of stopper defining the coinciding surface and the second guide surface.

The seal assembly of claim 17, wherein the plug assembly includes a guide ring sized so that when slid it engages the inner surface of the shell, so as to define the second guide surface, and a seal ring which has an external surface dimensioned so that the slide would engage and seal with the interior surface of the housing, in order to define the matching surface.

19. The seal assembly of claim 18, characterized in that a first part retracted from the plug forms the relief vacuum.

20. The seal assembly of claim 19, characterized in that the first retracted part of the cap is positioned adjacent to the seal ring.

The seal assembly of claim 19, characterized in that the first retracted part of the plug is positioned between the guide ring and the seal ring.

22. The seal assembly of claim 20, further including a second relief gap formed by a second retracted part of the plug formed on one side of the seal ring, opposite the first retracted part of the plug.

23. The seal assembly of claim 13, characterized in that the guide member includes a seal assembly defining the seal surface and the first guide surface, further characterized in that the regulator valve member assembly includes a tang coupled to the seal member. regulating valve and has an outer surface that defines the matching surface and the second guide surface.

24. The seal assembly of claim 23, characterized in that the sealing surface and the first guide surface are defined by a same inner surface of the obturator assembly, and in which the matching surface and the second guide surface are defined by a same part of the outer surface of the spike.