2-axis base retainer

Abstract

The valve assembly includes a valve body defining a valve passage and a valve seat disposed within the valve body. The valve assembly also includes a valve actuator movable between a closed position in which the valve actuator is sealed against the valve seat to close the valve passage and an open position in which the valve actuator is spaced from the valve seat to open the valve passage. The valve assembly includes a valve seat retainer disposed within the valve body in contact with the valve seat. The valve seat retainer is configured to provide both axial and lateral support to the valve seat when the valve actuator is sealed against the valve seat in the closed position.

Description

Technical Field

[0001] Related Applications This application claims the benefit of U.S. Provisional Patent Application No. 63 / 118,997, filed Nov. 30, 2020, which is hereby incorporated by reference in its entirety.

[0002] This application generally relates to valves, and more particularly to high purity valves used in semiconductor manufacturing.

Background Art

[0003] Within the semiconductor industry, there are numerous departments with specific product needs. One such department is high temperature vapor deposition. In such applications, process chemicals in liquid or solid form are heated to generate vapor pressure, and the heated vapor is sent to a reaction chamber. It is important to maintain a high vapor temperature throughout the delivery to the reaction chamber so that the vapor does not condense. For example, current vapor deposition techniques may be carried out at high temperatures of up to 200° C. (293° F), and for new chemicals and to improve the throughput of existing low vapor pressure materials by increasing the pressure, it is necessary to raise the operating temperature up to 250° C. (482° F). Materials used in the manufacture of such high purity valves include 316I stainless steel remelted twice, and by further polishing its surface by electropolishing, a chromium oxide rich layer is provided that resists corrosion by various gases used in semiconductor manufacturing.

Summary of the Invention

Problems to be Solved by the Invention

[0004] High-purity valves for operation under increasing temperatures require a well-supported valve seat to prevent it from being pushed out by the applied closing force. In a typical design, the valve seat is held in place without being pushed out by pressing a metal body onto a soft valve seat material. Specifically, the valve seat is restrained by pressing or stretching a lip on the valve body onto a projection of the valve seat. This design presents two problems for such high-purity valves. First, the displacement of the valve body material during compression can cause surface damage to the material. For example, the compression described above may puncture the chromium oxide surface layer on stainless steel, leaving the valve body in a state where it is susceptible to corrosion. Second, when valve seat replacement is necessary or desirable, it is not easy to remove and replace the valve seat. For example, in canister configurations often used in vapor deposition, when a chemical delivery canister is empty, the canister and the delivery and purging valves must be completely disassembled, cleaned, and reassembled, or the entire assembly must be replaced. At least with respect to canister valves, the valve seat is typically replaced after each canister filling cycle. Reassembling and / or replacing these valves becomes problematic when the valve seat is difficult or impossible to remove, such as when the seat is crimped on, leading to wasted time and the disposal of expensive welded or crimped valve assemblies. [Means for solving the problem]

[0005] The valve disclosed herein solves problems arising from or related to conventional crimped or welded valve seats. Instead of crimped or welded valve seats, the valve configuration of the disclosed herein includes a flexible twin-screw valve seat retainer, which is configured to fix the valve seat within the valve body, thereby supporting the valve seat laterally and axially to prevent movement of the valve seat when loaded (i.e., when sealed by the valve actuator). The valve seat retainer is a flexible member configured to transmit the force constantly applied by the valve actuator when fully assembled into an axial force to hold the valve seat in place. At the same time, the deflection of the valve seat retainer drives the valve seat retainer laterally inward relative to the valve seat, thereby transmitting a lateral force to support the valve seat laterally and preventing the valve seat from being pushed out when loaded under increasing temperature. The valve seat retainer includes a plurality of holes to allow gas to flow through the valve seat retainer. The use of the above-mentioned valve seat retainer provides a well-supported valve seat that can be easily replaced, while preventing damage to the surface material of the valve body and subsequent corrosion.

[0006] One aspect of the present invention is a valve assembly comprising a valve body defining a valve passage, a valve seat disposed within the valve body, and a valve actuator, the valve actuator being movable between a closed position in which the valve actuator is sealed against the valve seat to close the valve passage and an open position in which the valve actuator is separated from the valve seat to open the valve passage. The valve assembly also comprises a valve seat retainer, which is disposed within the valve body in contact with the valve seat and is configured to prevent the valve seat from being pushed out when the valve actuator is sealed against the valve seat in the closed position by applying axial and lateral support forces to the valve seat.

[0007] Another aspect of the present invention is a method for replacing a used valve seat in a valve assembly, the method comprising the steps of: removing a valve seat retainer from the valve assembly; removing the used valve seat from the valve assembly; inserting a new valve seat into the valve assembly; and reinserting the valve seat retainer into the valve assembly in contact with the new valve seat, wherein the inserted valve seat retainer is configured to prevent the new valve seat from being pushed out when the valve actuator is sealed against the valve seat in the closed position by providing axial and lateral support forces to the new valve seat.

[0008] Another aspect of the present invention is a method for assembling a valve assembly, the method comprising the steps of: inserting a valve seat retainer into the valve body of the valve assembly such that the inner edge of the valve seat retainer contacts the valve seat in the valve assembly; and inserting a valve actuator into the valve body such that the outer edge of the valve actuator contacts the outer edge of the valve seat retainer. The assembly method also comprises the steps of: fixing the valve actuator within the valve body so that an axial load force is applied to the outer edge of the valve seat retainer; and applying axial and lateral support forces to the valve seat by the valve seat retainer.

[0009] To achieve the above-mentioned and related objectives, the present invention has features that are fully described hereafter, particularly those indicated in the claims. The following description and accompanying drawings detail specific exemplary embodiments of the present invention. However, these embodiments represent only a fraction of the various ways in which the principles of the present invention can be employed. Other objects, advantages, and novel features of the present invention will become apparent when the following "Modes for Carrying Out the Invention" are considered together with the drawings. [Brief explanation of the drawing]

[0010] [Figure 1] Figure 1 is a cross-sectional view of a valve assembly including a valve seat retainer. [Figure 2]Figure 2 is a perspective view of the valve seat retainer and valve seat used in the valve assembly shown in Figure 1. [Figure 3A] Figure 3A is a cross-sectional view of the valve assembly shown in Figure 1, in a partially assembled state. [Figure 3B] Figure 3B is a cross-sectional view of the valve assembly of Figure 1 in the open position when fully assembled. [Figure 4] Figure 4 is an enlarged cross-sectional view of the valve assembly in Figures 1, 3, and 4, illustrating further details related to the valve seat and valve seat retainer. [Figure 5] Figure 5 is a flowchart showing how to replace a used valve seat in a valve assembly. [Figure 6] Figure 6 is a flowchart showing how to assemble the valve assembly. [Modes for carrying out the invention]

[0011] Embodiments of this application will now be described with reference to the drawings. Throughout the drawings, the same reference numerals are used to refer to similar elements. It should be understood that these drawings are not necessarily to scale.

[0012] Figure 1 shows a valve assembly 10 having a valve body 12 defining a valve passage 14, and a valve seat 16 disposed within the valve body 12. The valve passage 14 is configured to allow material to flow through it, for example, along the direction of the arrows shown within the valve passage 14, or in the opposite direction of the arrows. The valve assembly 10 includes a valve actuator 18 which is movable between a closed position in which the valve actuator 18 is sealed against the valve seat 16 to close the valve passage 14 and prevent the material from flowing through the valve, and an open position in which the valve actuator 18 is separated from the valve seat 16 to open the valve passage 14 and allow the material to flow through the valve. The valve assembly 10 also includes a twin-screw valve seat retainer 20 disposed within the valve body 12 in contact with the valve seat 16. The valve seat retainer 20 is flexible and supported within the valve assembly 10, thereby providing a well-supported valve seat 16 and preventing the valve seat 16 from being pushed out when the valve actuator 18 is sealed against the valve seat 16 in the closed position. For example, the valve seat retainer 20 may be positioned within the valve body 12 such that its inner edge 20a contacts the valve seat 16 and its outer edge 20b contacts the valve actuator 18 (for example, the diaphragm 26 of the valve actuator 18, which will be described in more detail below), so that the flexible valve seat retainer 20 flexes when subjected to load within the valve assembly 10. In this way, the twin-screw valve seat retainer 20 is configured to provide both axial and lateral support forces to the valve seat 16.

[0013] In the embodiment shown in Figure 1, the valve actuator 18 includes a piston 24 and a diaphragm 26. The piston 24 may be capable of linear motion between a first position and a second position. As the piston 24 moves between the first and second positions, it moves the diaphragm 26 between an unsealed position and a sealed position, respectively. Specifically, in the open position of the valve actuator 18, the piston 24 of the valve actuator 18 is in the first position and the diaphragm 26 is in the unsealed position (lifted away from the valve seat 16). In the closed position of the valve actuator 18, the piston 24 is in the second position and the diaphragm 26 is in the sealed position (sealed to the valve seat 16). As shown in Figure 1, the diaphragm 26 is biased to the unsealed position, where the diaphragm is separated from the valve seat 16, thereby opening the valve passage 14 so that material can flow through the valve. The diaphragm 26 can be moved by the piston 24 from an unsealed position to a sealed position, in which case the diaphragm seals the valve seat 16 to close the valve passage 14 and prevent material from flowing through the valve. In the sealed position, the diaphragm 26 is configured to have an outer shape that conforms to the shape of the valve seat 16 in order to form a proper seal between the diaphragm and the valve seat. The valve actuator 18 may include a cap 28 positioned on and around the piston 24 and a nut 30 configured to secure the piston 24, diaphragm 26, and cap 28 within the valve assembly 10. The valve actuator 18 including the piston 24, diaphragm 26, cap 28, and nut 30 is described as a non-limiting example, and it should be understood that other types of valve actuators may also be applicable to the valve assembly 10 described herein.

[0014] During assembly, the nut 30 engages with the valve body 12 to secure the valve actuator. For example, the nut 30 may have a threaded portion which is configured to engage with and secure the corresponding threaded portion of the valve body 12. When the nut 30 is engaged with the valve body 12, the nut 30 applies an axial load force to the outer edge of the cap 28 and diaphragm 16, pushing the cap 28 and diaphragm 16 against the outer edge 20b of the valve seat retainer 20. Thus, the valve actuator 18, specifically the diaphragm 26 via the cap 28 and nut 30, applies an axial load force to the outer edge 20b of the valve seat retainer 20, causing deflection and translational movement of the valve seat retainer, thereby applying axial and lateral support forces to the valve seat 16. Once the valve assembly 10 is fully assembled and the nut 30 is fully engaged and secured with the valve body 12, the axial load, axial support force, and lateral support force remain constant throughout the entire operation of the valve assembly 10 as the piston 24 of the valve actuator 18 moves between the open and closed positions.

[0015] Moving to Figure 2, for further explanation, the valve seat retainer 20 and valve seat 16 are shown separated from the rest of the valve assembly 10 and as a single unit. As shown, the valve seat retainer 20 includes a plurality of holes 32 disposed between the outer edge 20b and the inner edge 20a of the valve seat retainer 20, allowing material to pass through the valve seat retainer 20, thereby allowing material to flow through the valve passage 14 when the valve actuator 18 is in the open position. The valve seat retainer 20 may be made of, for example, Elgiloy. The valve seat 16 may be made of, for example, Teflon® or perfluoroalkoxy alkane (PFA). The valve seat retainer 20 and valve seat 16 may be annular in shape, for example.

[0016] The valve seat retainer 20 is configured to extend from its inner edge 20a to its outer edge 20b at an angle such that when it is inserted into the valve assembly 10, the valve seat retainer 20 flexes and can impart axial and lateral support forces to the valve seat 16. Specifically, referring to Figure 3A, during the assembly of the valve seat assembly 18, the valve seat 16 is inserted into the valve body 12 such that the inner edge 20a of the valve seat retainer 20 contacts the valve seat 16, and the outer edge 20b of the valve seat retainer 20 extends from the valve seat 16 toward the valve actuator 18 at the aforementioned angle. Figure 3A shows the valve seat retainer 20 in the partially assembled valve assembly 10 before the nut 30 of the valve actuator 18 is fully engaged and secured with the valve body 12, and before the valve actuator 18 imparts axial load force to the outer edge 20b of the valve seat retainer 20. Referring to Figure 3B, after the valve actuator 18 is inserted and the nut 30 is fully engaged and secured with the valve body 12, the valve actuator 18, specifically the diaphragm 26 via the cap 28 and nut 30, applies an axial load force 36 to the outer edge 20b of the valve seat retainer 20. This causes the valve seat retainer 20 to flex, applying an axial support force 38 and a lateral support force 34 to the valve seat 16. Therefore, when moving the valve actuator 18 from the open position to the closed position, the valve seat 16 is prevented from being pushed out.

[0017] Specifically, referring to Figure 4, the valve seat 16 is configured to fit at least partially into the notch 42 of the valve body 12, thereby supporting the valve seat 16 at least partially on its inner surface 16a, bottom surface 16b, and outer surface 16c. However, the valve seat 16 may protrude beyond the notch 42 of the valve body 12 at its upper surface 16d, thereby allowing the valve actuator 18 to seal the valve seat 16 at its upper surface 16d when the valve actuator 18 is in the closed position. Without the valve seat retainer 20, the upper surface 16d of the valve seat 16 could be pushed laterally outward (towards the right in Figure 4) from the notch 42 when the valve actuator 18 moves from the open position to the closed position to seal the upper surface 16d of the valve seat 16. The valve seat retainer 20 is configured to provide a lateral support force 34 to prevent such pushing by contacting the outer surface 16c of the valve seat 16. As described above, the valve seat retainer 20 is also configured to apply an axial support force 38 to the valve seat 16. That is, the outer surface 16c of the valve seat 16 may have an L-shaped cross-section as shown in Figure 4, and the inner edge 20a of the valve seat retainer 20 contacts both legs of the L-shaped cross-section. In this way, the inner edge 20a of the valve seat retainer 20 is configured to apply a lateral support force 40 to the first leg L1 of the L-shaped cross-section while simultaneously applying an axial support force 38 to the second leg L2 of the L-shaped cross-section. As a result, when the valve actuator 18 moves from the open position to the closed position and seals the upper surface 16d of the valve seat 16, the valve seat 16 is fixed and supported within the notch 42 in both the axial and lateral directions.

[0018] A method 100 for replacing a used valve seat in a valve assembly is described with reference to Figure 5. The valve assembly used in method 100 is the same as the valve assembly 10 described above. Method 100 includes the steps of removing a valve seat retainer (such as a valve seat retainer 20) from the valve assembly 102 and removing the used valve seat from the valve assembly 104. Method 100 may then include the steps of inserting a new valve seat into the valve assembly 106 and reinserting the valve seat retainer into the valve assembly (or replacing it with a new valve seat retainer) 108. As described above with reference to valve seat retainer 20, the valve seat retainer is inserted or replaced so as to contact the new valve seat, thereby the valve seat retainer is configured to prevent the new valve seat from being pushed out when the actuator is sealed against the valve seat in the closed position by providing axial and lateral support forces to the new valve seat as the valve actuator moves from the open position to the closed position. Specifically, step 108, which involves inserting or replacing a valve seat retainer, may include positioning the outer edge of the valve seat retainer between the valve actuator and the valve body of the valve assembly, and bringing the inner edge of the valve seat retainer into contact with the valve seat.

[0019] Referring to Figure 6, a method 200 for assembling a valve assembly such as the valve assembly 10 described herein is described. Method 200 includes step 202 of inserting a valve seat retainer into the valve body of the valve assembly so that the inner edge of the valve seat retainer contacts the valve seat in the valve assembly. Method 200 then includes step 204 of inserting a valve actuator into the valve body so that the valve actuator contacts the outer edge of the valve seat retainer. The valve actuator may include a piston and a diaphragm, such as the piston 24 and diaphragm 26 described above with reference to the valve actuator 18 in Figure 1. Thus, step 204 for inserting the valve actuator may include inserting the piston and diaphragm so that the outer edge of the diaphragm contacts the outer edge of the valve seat retainer.

[0020] Method 200 then includes step 206 of fixing the valve actuator within the valve body, whereby an axial loading force is applied to the outer edge of the valve seat retainer, causing the valve seat retainer to deflect and impart an axial support force and a lateral support force to the valve seat. For example, the valve actuator may further include a cap such as cap 28 described above with reference to valve actuator 18 of FIG. 1. Thus, step 206 of fixing the valve actuator may include placing a nut such as nut 30 described above with reference to FIG. 1 over the cap and engaging the nut with the valve body to fix the valve actuator. For example, the nut may have a threaded portion configured to engage and be fixed to a corresponding threaded portion of the valve body. When the nut is engaged with the valve body, the nut applies an axial loading force to the outer edges of the cap and diaphragm, pushing the cap and diaphragm against the outer edge of the valve seat retainer. Thus, the valve actuator, specifically the diaphragm via the cap and nut, as described above, applies an axial loading force to the outer edge of the valve seat retainer, causing deflection and translational movement of the valve seat retainer, thereby imparting an axial support force and a lateral support force to the valve seat. Thus, method 200 further includes step 208 of applying an axial support force and a lateral support force to the valve seat.

[0021] The valve assembly includes a valve body defining a valve passage, a valve seat disposed within the valve body, and a valve actuator movable between a closed position where the valve actuator is sealed against the valve seat to close the valve passage and an open position where the valve actuator is spaced from the valve seat to open the valve passage. The valve assembly also includes a valve seat retainer disposed within the valve body in contact with the valve seat and configured to impart both an axial support force and a lateral support force to the valve seat when the valve actuator is sealed against the valve seat in the closed position.

[0022] The valve seat retainer may include an outer edge disposed between the valve actuator and the valve body and an inner edge in contact with the valve seat.

[0023] The valve seat retainer may be flexible and can apply the axial support force and the lateral support force to the valve seat by bending when receiving a load within the valve assembly.

[0024] The valve seat retainer may be configured to extend at an angle from the inner edge portion to the outer edge portion.

[0025] The valve seat retainer may include a plurality of holes disposed between the outer edge portion and the inner edge portion to allow material to pass through the valve passage when the valve actuator is in the open position.

[0026] The valve actuator may include a piston and a diaphragm, and the diaphragm is movable by the piston between a closed position where the diaphragm seals the valve seat to close the valve passage and an unsealed position where the diaphragm is spaced apart from the valve seat to open the valve passage.

[0027] The valve actuator may further include a cap disposed on the piston, and the valve assembly may include a nut disposed on the cap and configured to engage with the valve body to fix the valve actuator within the valve body.

[0028] The valve seat may be made of Teflon.

[0029] The valve seat retainer may be made of Elgiloy.

[0030] The valve seat and the valve seat retainer may be annular.

[0031] A method for replacing a used valve seat in a valve assembly includes the steps of: removing a valve seat retainer from the valve assembly; removing the used valve seat from the valve assembly; inserting a new valve seat into the valve assembly; and reinserting the valve seat retainer into the valve assembly in contact with the new valve seat, thereby configuring the inserted valve seat retainer to prevent the new valve seat from being pushed out when the valve actuator is sealed against the valve seat in the closed position by providing axial and lateral support forces to the new valve seat.

[0032] The step of inserting the valve seat retainer may include positioning the outer edge of the inserted valve seat retainer between the valve actuator and the valve body, and bringing the inner edge of the inserted valve seat retainer into contact with the valve seat.

[0033] The removed valve seat retainer and the inserted valve seat retainer may be the same valve seat retainer.

[0034] A method for assembling a valve assembly includes the steps of inserting a valve seat retainer into the valve body of the valve assembly such that the inner edge of the valve seat retainer contacts the valve seat in the valve assembly, and inserting a valve actuator into the valve body such that the outer edge of the valve actuator contacts the outer edge of the valve seat retainer. The assembly method also includes the steps of fixing the valve actuator inside the valve body so that an axial load force is applied to the outer edge of the valve seat retainer, and applying axial and lateral support forces to the valve seat by the valve seat retainer.

[0035] The step of inserting the valve actuator may include inserting the piston and diaphragm of the valve actuator into the valve body such that the outer edge of the diaphragm contacts the valve seat retainer of the valve seat retainer.

[0036] The step of fixing the valve actuator within the valve body may include placing a nut on the cap of the valve actuator and engaging the nut with the valve body such that the nut applies the axial load force to the outer edge of the valve actuator and the outer edge of the valve seat retainer.

[0037] While the present invention has been illustrated and described with reference to one or more specific embodiments, it will be apparent to those skilled in the art, upon reading and understanding this specification and the accompanying drawings, that equivalent alternative and modified forms will be conceivable. In particular, with respect to the various functions performed by the elements described above (components, assemblies, devices, compositions, etc.), the terms used to describe these elements (including references to “means”) are intended, unless otherwise specified, to correspond to any element that performs the specified function of the element described (i.e., is functionally equivalent), and may not be structurally equivalent to the structures disclosed in one or more exemplary embodiments of the present invention shown herein that perform the above functions. Furthermore, while certain features of the present invention have been described with reference to only one or more of the multiple exemplary embodiments, such features can also be combined with one or more other features of other embodiments so as may be desirable and advantageous for any or particular application.

Claims

1. The valve body that defines the valve passage; A valve seat positioned within the valve body; A valve actuator, wherein the valve actuator is movable between a closed position in which it is sealed against the valve seat to close the valve passage and an open position in which it is separated from the valve seat to open the valve passage; and A valve seat retainer is positioned within the valve body in contact with the valve seat and is configured to prevent the valve seat from being pushed out when the valve actuator is sealed against the valve seat in the closed position by applying axial and lateral support forces to the valve seat. A valve assembly comprising, The aforementioned valve seat retainer is: The outer edge portion disposed between the valve actuator and the valve body; and Inner edge that contacts the valve seat Includes, The valve seat retainer is flexible and, when subjected to a load within the valve assembly, deflects, thereby imparting the axial and lateral support forces to the valve seat. The valve actuator is: piston; and A diaphragm, positioned above the valve seat retainer, and movable by the piston between a sealed position in which the diaphragm seals the valve seat to close the valve passage and an unsealed position in which the diaphragm moves away from the valve seat to open the valve passage. Includes, A valve assembly in which the outer edge of the diaphragm contacts the outer edge of the valve seat retainer, and the diaphragm applies the load to the outer edge of the valve seat retainer.

2. The valve assembly according to claim 1, wherein the valve seat retainer is configured to extend at an angle from the inner edge to the outer edge of the diaphragm.

3. The valve assembly according to claim 1 or 2, wherein the valve seat retainer includes a plurality of holes disposed between the outer edge and the inner edge of the valve seat retainer to allow material to pass through the valve passage when the valve actuator is in the open position.

4. The valve actuator further includes a cap positioned on the piston, and the valve assembly further includes a nut positioned on the cap and configured to engage with the valve body to secure the cap within the valve body, according to claim 1.

5. The valve assembly according to any one of claims 1 to 4, wherein the valve seat is made of Teflon®.

6. The valve assembly according to any one of claims 1 to 5, wherein the valve seat retainer is made of Elgiloy.

7. The valve assembly according to any one of claims 1 to 6, wherein the valve seat and the valve seat retainer are annular.

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