WO2014182756A1

WO2014182756A1 - Valve with orifice plate

Info

Publication number: WO2014182756A1
Application number: PCT/US2014/037050
Authority: WO
Inventors: III William H. GLIME
Original assignee: Swagelok Company
Priority date: 2013-05-09
Filing date: 2014-05-07
Publication date: 2014-11-13

Abstract

A valve for controlling fluid flow and/or delivery includes a valve element in the form of a seal and a plate that has an orifice disposed between a valve inlet and a valve outlet. In an embodiment, the orifice plate may be a modified face seal gasket, for example a VCR® brand gasket or seal. Preferably, the orifice plate is removable and replaceable. The seal closes the valve by sealing directly against a surface of the orifice plate to block the orifice.

Description

VALVE WITH ORIFICE PLATE

Related Application

[0001] The present application claims the benefit of pending United States provisional patent application serial number 61/821,391 filed on May 9, 2013 titled VALVE WITH ORIFICE PLATE, the entire disclosure of which is fully incorporated herein by reference.

Technical Field of the Inventions

[0002] The inventions relate to fluid flow and delivery devices and methods, and more particularly to valves used to control fluid flow and delivery.

Background of the Inventions

[0003] Valves are well known for use as flow control devices for gas and liquid fluid delivery. In the semiconductor industry as well as others, delivery of process chemicals during various processing operations is controlled using valves, for example, high purity valves. Some of the more common applications for valves are chemical vapor deposition (CVD) and atomic layer deposition (ALD). In the example of liquid chemicals, precise control of the amount of liquid injected into a reaction chamber is important, and is often accompanied by use of chemical injection pulses with short duration, high speed and high operating cycles.

Brief description of the Drawings

[0004] Fig. 1 illustrates an exemplary valve and actuator assembly in isometric and that may incorporate the teachings herein,

[0005] Fig. 2 is the valve and actuator assembly of Fig. 1 in longitudinal cross-section along the line 2-2 in Fig. 1, with the valve in the open position,

[0006] Fig. 3 is an enlarged view of the circled portion of Fig. 2. Summary of the Inventions

[0007] A first inventive concept presented herein provides a valve that may be used for controlling flow and/or delivery of a fluid such as liquid or gas. In an embodiment, a valve includes a valve member having a valve element for example a seal, and an orifice plate with an orifice. The orifice is disposed between an inlet and an outlet of the valve. The valve member in a first position seals directly against the orifice plate to block the orifice. Additional embodiments of this concept are presented herein.

[0008] A second inventive concept presented herein provides a valve that may be used for controlling flow and/or delivery of a fluid such as liquid or gas. In an embodiment, a valve includes a movable valve member having a valve element for example a seal, and an orifice plate with an orifice. The valve member may comprise a bellows or a tied diaphragm or other movable member. The orifice is disposed between an inlet and an outlet of the valve. The valve member in a first position seals directly against the orifice plate to block the orifice. Additional embodiments of this concept are presented herein.

[0009] Another inventive concept presented herein provides a valve that may be used for controlling flow and/or delivery of a fluid such as liquid or gas. In an embodiment, a valve includes a valve member with a valve element for example a seal, and an orifice plate with an orifice. The orifice plate may be realized in the form of a modified face seal gasket, for example a VCR^® brand gasket or seal. The orifice is disposed between an inlet and an outlet of the valve. The valve member in a first position seals directly against the orifice plate to block the orifice. Additional embodiments of this concept are presented herein.

[0010] Another inventive concept presented herein provides a valve that may be used for controlling flow and/or delivery of a fluid such as liquid or gas. In an embodiment, a valve includes a valve member with a valve element for example a seal, and an orifice plate with an orifice. The valve member may comprise a bellows or a tied diaphragm or other movable member. The orifice plate may be realized in the form of a modified face seal gasket, for example a VCR^® brand gasket or seal. The orifice is disposed between an inlet and an outlet of the valve. The valve member in a first position seals directly against the orifice plate to block the orifice. Additional embodiments of this concept are presented herein.

[0011] Another inventive concept presented herein provides a valve that may be used for controlling flow and/or delivery of a fluid such as liquid or gas. In an embodiment, a valve includes a valve element or seal, and a removable face seal gasket with an orifice. The orifice is disposed between an inlet and an outlet of the valve. The valve element in a first position seals directly against the face seal gasket to block the orifice. Additional embodiments of this concept are presented herein.

[0012] Additional concepts presented herein include but are not limited to a valve that may be used for controlling fluid delivery with a discrete shutoff without residual evaporation. An exemplary application may be a valve for ALD or CVD processes for semiconductor manufacturing. The concepts therefore may be used in high purity applications if needed. The concepts also may be used for short chemical pulse duration and high number of actuation cycles. The concepts may be used for liquid or gas delivery. The concepts may be used in combination with any actuator that can move the valve member or valve element between first and second positions to close and open the valve.

Description of Exemplary Embodiments

[0013] With reference to the drawings, in an exemplary embodiment, a valve and actuator assembly 10 may include an actuator assembly 12 and a valve assembly 14. The actuator assembly 12 may be stacked on top of the valve assembly 14 or otherwise operably coupled therewith. Although this exemplary embodiment illustrates use of a pneumatic actuator, alternative embodiments may use other types of automatic actuators or a manual actuator.

[0014] The actuator assembly 12 and most of the valve assembly 14 may conveniently be designed as a modified BN series bellows-sealed valve which is available commercially from Swagelok Company, Solon, Ohio. The BN Series is also shown in the product catalog titled BELLOWS-SEALED VALVES which is publicly available online and otherwise, and is fully incorporated herein by reference. However, many other actuator designs and valve designs may alternatively be used. The inventions are also not limited to use with a bellows- sealed valve assembly, but may alternatively be used with many other valve designs, including but not limited to a tied diaphragm valve or a valve having a stem sealed by o-rings or packings such as may be used in conventional needle or plug valves and so on.

[0015] The actuator assembly 12 for convenience may be an actuator assembly that is sold commercially with the BN Series bellows-sealed valves. Therefore, a detailed explanation of the actuator assembly 12 is not necessary to understand and practice the present inventions. The configuration in the drawings is for a normally closed valve and actuator assembly, but alternatively the assembly may be practiced with a normally open configuration.

[0016] The actuator assembly 12 includes an actuator housing 16 with a piston 18 disposed therein. The piston 18 is operably coupled to a valve member 20, which in an embodiment may be an actuator stem 20. The piston 18 is operably coupled to a first or proximal end 20a of the actuator stem. At a second or opposite end 20b of the actuator stem, the actuator stem 20 is welded or otherwise secured to a first or distal end 22a of a bellows 22. A second or proximal end 22b of the bellows 22 is welded to a bushing 24. The actuator housing 16 is closed off by a cap 26 so that the piston 18 is disposed in a piston chamber 28. The welded bellows 22 and the bushing 24 may form a discrete bellows subassembly. A valve element or seal 31 , which in an embodiment may be a stem seal member 31 , is carried at the opposite or distal end 20b of the actuator stem 20. The valve element 31 may be retained with the actuator stem 20 by any convenient technique, including but not limited to a press fit, adhesive and so on.

[0017] The valve assembly 14 may for convenience be a modified version of a valve assembly that is sold commercially as part of the BN Series bellows-sealed valves. The BN series valve includes a valve body 30 that has a valve chamber 32 that receives the bellows 22 and the valve element 31. An inlet port 34 and an outlet port 36 communicate with the valve chamber 32. The valve chamber 32 is sealed off from the ambient environment by the bellows 22, as well as body seals between the bushing 24 and the valve body 30. This portion of the valve assembly 14 may be but need not be the same as the BN Series valve.

[0018] Disposed between the inlet port 34 and the outlet port 36 is an orifice plate 38. The orifice plate 38 is a modification of the BN Series valve assembly 14 and replaces the traditional valve seat of a BN Series valve. The orifice plate 38 may be realized in the form of a preferably flat and annular disc-like body 40 having a flow orifice 42 formed therein. The orifice 42 is fixed in size and appropriately sized to control flow of fluid used, for example, for chemical delivery in CVD and ALD processes, or as needed for other applications. The appropriate sizing of a flow orifice is known in the art and depends on many factors including the fluid upstream pressure, whether a gas assist is used, the downstream process interface, required flow capacity and so on, which may be similar to how an orifice of a traditional valve seat in the BN series or other valves is sized. [0019] The orifice plate 38 is disposed in the valve body 30 such that when the valve member (e.g. the actuator stem) 20 is in a closed position, the valve element (e.g. the stem seal) 31 forms a seal that shuts off flow between the inlet port 34 and the outlet port 36 by preferably direct contact against a first surface 38a of the orifice plate 38 (note that in Figs. 2 and 3 the valve is shown in the open position for a normally closed valve configuration.) In an embodiment as shown herein, the stem seal 31 forms a face seal against the first surface 38a of the orifice plate 38. The stem seal 31 is another modification of the BN series design, and is used in place of the BN series stem tip. The stem seal 31 may have a diameter that preferably is greater than the diameter of the orifice 42. In an embodiment of the stem seal 31 , the stem seal 31 is provided with a flat circular surface 44 to form the face seal with the orifice plate 38. Alternatively, the stem seal 31, the orifice plate 38 or both may have surface geometries that are other than flat to effect the face seal that is used to shut off flow through the orifice 42. In another alternative embodiment, the stem seal 31 may seal against a different surface of the orifice plate 38 that define and delimit the orifice 42. When the actuator stem 20 is translated to the open position by operation of the actuator assembly 12, fluid communication is established from the inlet port 34, through the orifice 42 into the valve chamber 32 and through the outlet port 36. Flow may be reversed if so needed.

[0020] The use of a stem seal 31 that seals directly against the orifice plate 38 provides a discrete shutoff of fluid flow through the orifice 42 with immediate cessation of chemical delivery to reduce or eliminate residual vaporization. Exemplary materials for the stem seal 31 include but are not limited to plastics such as PFA (perfluoalkoxy), PTFE, (polytetrafluoroethylene), PCTFE (polychlorotrifluoroethylene), PEEK

(polyetheretherkeytone), PI (polyimide), elastomers, and metals such as 316 stainless steel. The orifice plate 38 may be made of metal, for example, 316 stainless steel or other stainless steel or other metals or non-metals. In addition, the use of coatings or surface treatments on the seal 31 or the orifice plate 38 or both may be included as a way and means to enhance durability, seal performance, and/or modify the surface energy of the seals so as to influence liquid droplet behavior. For example, stainless steel surfaces may be surface treated with low temperature carburization processes, and/or the orifice plate 38 may be coated with a hydrophobic material.

[0021] The sub-combination of a valve element 31 and an orifice plate 38 as may be used in a valve is an embodiment that is separately claimed herein. In a more specific embodiment, the orifice plate 38 preferably is a discrete component that is removable from the valve after it has been installed.

[0022] In accordance with another embodiment, for convenience the orifice plate 38 may be realized in the form of a modified face seal gasket, for example, a modified VCR^® brand gasket or seal 38. VCR^® brand metal gasket face seal fittings are commercially available from Swagelok Company, Solon, Ohio. These VCR^® brand fittings are also shown in the product catalog entitled VCR^® METAL GASKET FACE SEAL FITTINGS which is publicly available and is fully incorporated herein by reference, and are also described in US Patent No. 3,521,910 which is also fully incorporated herein by reference. The gasket may be modified for use as an orifice pate 38 with the present inventions in the sense that instead of using a VCR^® brand gasket flow-through hole that is comparable in size (flow area) to a flow path defined by an inside diameter of a conduit, the gasket is provided with the fixed orifice 42. But, as noted above the orifice 42 size will be determined by many factors related to the desired flow characteristics for the fluid being controlled by the valve assembly 14.

[0023] The gasket shaped orifice plate 38 may be installed into the valve body 30 using the known VCR^® brand fitting technology. In an embodiment as shown in Fig. 2, the valve body 30 may be provided with a first annular seal bead 46 and second seal bead 48 may be provided with a VCR^® brand connector or gland 50. Many different VCR^® brand connector configurations may be used as needed. In Fig. 2 is shown a male union connector as an example. The gasket 38 is installed into the valve body 30 so that the gasket first surface 38a makes contact with the first seal bead 46. Then the connector 50 may be threaded into the valve body 30 so that the second seal bead 48 contacts a second surface 38b of the gasket. When the connector 50 is tightened down, the seal beads 46, 48 are compressed against and seal against the gasket 38, thereby forming fluid tight seals between the gasket 38 and the valve body 30 and the connector 50.

[0024] Connections for providing fluid into the inlet port 34 may be accomplished in many different ways as alternatives to using the VCR^® brand connector 50. Also, the orifice plate 38 need not be installed with VCR^® brand technology but may be retained in the valve body 30 in many different ways and configurations. [0025] As noted above, the stem seal 31 has a seal surface 44 that preferably is greater in diameter than the orifice 42. When a VCR^® brand connection is used for the orifice plate 38, the first seal bead 46 will have a larger diameter than the seal surface 44.

[0026] The use of VCR^® brand technology facilitates use of an orifice plate 38 that is easily replaceable. However, other orifice plate 38 installation techniques may alternatively be used that also can provide for a replaceable orifice plate. Note that in an exemplary embodiment as herein, the orifice plate 38 is easily accessed for installation and removal through the threaded bore 52 that is used for the connector 50 without having to disassemble any other part of the valve and actuator assembly 10.

[0027] A bonnet 54 may be used to connect the actuator assembly 12 with the valve assembly 14. The bonnet 54 arrangement may be the same as used with the BN series actuator and valve assemblies. A bonnet nut 56 provides a threaded connection with the valve body 30 to secure the bonnet 54 against the bushing 24. The bonnet 54 may be connected to the actuator housing 16 with a retaining ring 58. A spring 60 is disposed in the bonnet 54 and is compressed between a bonnet shoulder 62 and a retaining ring 64 on the actuator stem 20. This configuration thereby provides a normally closed valve because the compressed spring will urge the actuator stem 20 downward (as viewed in Fig. 2) so as to extend the bellows 22 and force the stem seal 31 against the orifice plate 38 to block the orifice 42.

[0028] The actuator housing 16 is provided with a first pressurized air inlet port 66 that communicates with the piston chamber 28. When pressurized air is applied to the piston chamber 28 through the first pressurized air inlet port 66, the piston is displaced against the force of the spring 60 which moves the stem seal 31 away from the orifice plate 38 and opens the orifice 42, thereby allowing fluid to flow from the inlet port 34 to the outlet port 36. A second pressurized air inlet port 68 may be provided for actuators that will operate for normally open valve configurations.

[0029] It is intended that the inventions not be limited to the particular embodiments disclosed for carrying out the inventions, but that the inventions will include all embodiments falling within the scope of the appended claims.

Claims

Claims:

1. A valve, comprising: a valve body comprising a flow path for fluid from an inlet to an outlet, a valve member disposed in said valve body and that can be moved between a first position and a second position, a plate disposed in said valve body between said inlet and said outlet, said plate comprising an orifice, said valve member comprising a seal that will block said orifice when said valve member is in said first position.

2. The valve of claim 1 wherein said valve member comprises a bellows or a tied diaphragm.

3. The valve of claim 1 wherein said valve member comprises a bellows and an actuator stem, said bellows being disposed between said inlet and said outlet, said actuator stem being operable to move said valve stem between said first position and said second position.

4. The valve of claim 3 wherein said seal is disposed on said actuator stem.

5. The valve of claim 1 in combination with an actuator that is operable to move said valve member to said first position.

6. The valve of claim 1 wherein said plate comprises a modified metal VCR^® brand face seal gasket that has said orifice therein.

7. The valve of claim 6 wherein said valve body comprises an annular bead that seals against a first surface of said gasket, said bead having a larger diameter than said orifice.

8. The valve of claim 7 wherein said inlet comprises a VCR^® brand gland having a second annular bead that seals against a second surface of said gasket.

9. The valve of claim 1 wherein said seal comprises one or more of the following: PFA (perfluoalkoxy), PTFE, (polytetrafluoroethylene), PCTFE (polychlorotrifluoroethylene), PEEK (polyetheretherkeytone), PI (polyimide), elastomers, metals such as 316 stainless steel.

10. The valve of claim 1 wherein said plate presents a flat surface that faces said seal, and said seal comprises a flat surface that seals against said facing plate flat surface.

11. The valve of claim 1 wherein the fluid comprises a liquid chemical and the valve comprises an ALD or a CVD valve.

12. A valve, comprising: a valve element and a face seal gasket, said gasket comprising an orifice, said orifice being disposed between an inlet and an outlet of the valve, said valve element in a first position seals directly against said gasket to block said orifice.

13. The valve of claim 12 comprising a valve member that comprises said valve element and that operates to move said valve element between said first position to block said orifice and a second position to unblock said orifice.

14. The valve of claim 13 wherein said valve member comprises an actuator stem.

15. The valve of claim 14 in combination with an actuator, said actuator being operable to move said actuator stem.

16. The valve of claim 14 wherein said actuator comprises a pneumatic actuator or a manual actuator.

17. The valve of claim 14 wherein said valve member comprises a bellows or a tied diaphragm.

18. The valve of claim 12 wherein said gasket comprises a metal face seal gasket.

19. The valve of claim 18 wherein said gasket comprises stainless steel.

20. The valve of claim 12 wherein said gasket is removable from the valve through an inlet or outlet port of the valve.

21. The valve of claim 12 wherein said gasket is releasably compressed between a first annular bead and a second annular bead.