ELECTROSTATIC DISCHARGE MITIGATION VALVE

Abstract

This disclosure provides operative components that mitigate electrostatic charge in fluid circuits. Illustrative embodiments include diaphragm valves that provide fluid control and allow static charge to dissipate when these diaphragm valves are grounded.

Claims

1. An operative component for a fluid circuit comprising a housing having i) one or more fluid intake fitting, ii) one or more fluid output fitting, and iii) one or more fluid control component, wherein the fluid control component comprises a conductive fluoropolymer to transfer static charge from the fluid control component to ground.

2. The operative component of claim 1, wherein the operative component comprises a valve controlling fluid flow from the intake fitting to the output fitting.

3. The operative component of claim 1, wherein the operative component comprises a diaphragm valve.

4. The operative component of claim 3, wherein the diaphragm valve comprises a flexible fluoropolymer body to control fluid flow from the intake fitting to the output fitting.

5. The operative component of claim 4, wherein the flexible fluoropolymer body comprises a conductive fluoropolymer.

6. The operative component of claim 4, wherein the flexible fluoropolymer body comprises a conductive fluoropolymer segment around a perimeter of a non-conductive flexible fluoropolymer body.

7. The operative component of claim 6, wherein the conductive fluoropolymer segment is in conductive contact with the non-conductive flexible fluoropolymer body.

8. The operative component of claim 1, wherein the conductive fluoropolymer comprises tetrafluoroethylene polymer loaded with conductive material.

9. A diaphragm valve for a fluid circuit comprising two or more housing components, one or more intake fitting, one or more output fitting, and a diaphragm; wherein the diaphragm comprises a flexible conductive fluoropolymer body to transfer static charge from the diaphragm to ground.

10. The diaphragm valve of claim 9, wherein the conductive fluoropolymer segment is in conductive contact with a non-conductive flexible fluoropolymer body.

11. The diaphragm valve of claim 9, wherein the conductive fluoropolymer segment comprises perfluoroalkoxy alkane polymer (PFA), ethylene and tetrafluoroethylene polymer (ETFE), ethylene, tetrafluoroethylene and hexafluoropropylene polymer (EFEP), fluorinated ethylene propylene polymer (FEP), tetrafluoroethylene polymer (PTFE), or combinations thereof.

12. The diaphragm valve of claim 9, wherein the conductive fluoropolymer segment mitigates electrostatic discharge in a flange segment of the diaphragm valve.

13. The diaphragm valve of claim 9, further comprising a gasket, wherein the gasket comprises a conductive fluoropolymer to transfer static charge from the diaphragm valve to ground.

14. The diaphragm valve of claim 13, wherein the gasket comprises tetrafluoroethylene polymer loaded with conductive material.

15. A method of making a fluid circuit with an integrated electrostatic discharge mitigation system comprising installing an operative component of claim 1 in the fluid circuit and grounding the operative component.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings included in this disclosure illustrate embodiments of the present disclosure and, along with the description, serve to explain the principles of the disclosure. The drawings are only illustrative of certain embodiments and do not limit the disclosure.

[0022] FIG. 1 depicts an isometric view of a diaphragm valve, according to one or more embodiments of this disclosure.

[0023] FIG. 2 depicts a cross section view of a diaphragm valve, according to one or more embodiments of this disclosure.

[0024] FIG. 3 depicts an exploded view of a diaphragm valve, according to one or more embodiments of this disclosure.

[0025] FIG. 4 depicts an isometric view of a diaphragm valve actuator, according to one or more embodiments of this disclosure.

[0026] FIG. 5 depicts a digital image of an embodiment of a flexible fluoropolymer body of a diaphragm valve, according to one or more embodiments of this disclosure.

[0027] FIG. 6 depicts a digital image of another embodiment of a flexible fluoropolymer body of a diaphragm valve, according to one or more embodiments of this disclosure.

[0028] FIG. 7 depicts still another digital image of an embodiment of a flexible fluoropolymer body of a diaphragm valve, according to one or more embodiments of this disclosure.

[0029] FIG. 8 depicts a schematic view of a fluid control circuit comprising an operative component, according to one or more embodiments of this disclosure.

[0030] The embodiments of this disclosure are amenable to various modifications and alternative forms, and certain specifies have been shown, for example, in the drawings and will be described in detail. It is understood that the intention is not to limit the disclosure to the particular embodiments described; the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

DETAILED DESCRIPTION

[0031] This disclosure reports embodiments of an operative component or a diaphragm valve for applications in a fluid handling system with ESD mitigation having a fluid flow passageway from a fluid supply to one or more downstream process stages. Conventional and some ESD mitigation fluid circuits are reported, for example, in International patent application. WO 2017/210293, which is incorporated herein by reference, except for express definitions or patent claims contained therein. Other ESD mitigation fluid circuits are reported, for example, in an Entegris brochure, FLUOROLINE Electrostatic (ESD) Tubing, 2015-2017.

[0032] FIG. 1 is an isometric view that illustrates an embodiment of a diaphragm valve 10. The diaphragm valve 10 includes an inlet fitting 12 and an outlet fitting 14. The inlet valve 12 and outlet valve 14 are connected to a first housing component 16 having a first flange segment 18. The diaphragm valve further includes a second housing component 20 having a second flange 22. The first flange 18 and second flange 22 are configured to provide a leak proof connection when the diaphragm valve is used in a fluid circuit to control fluid flow between the inlet fitting 12 and the outlet fitting 14. FIG. 1 also illustrates a ground tab 24 that is in conductive contact with a diaphragm comprising a flexible fluoropolymer body (not shown) within the internal portions of the first housing component 16 and second housing component 20. Ground tab 24 allows transfer of static charge when connected to ground. FIG. 1 also illustrates an external portion of an actuator 26 that provides both internal and external structure to adjust or control the position of the flexible fluoropolymer body (not shown) in the internal portion of the diaphragm valve. The position of the flexible fluoropolymer body controls fluid flow from the inlet fitting to the outlet fitting.

[0033] FIG. 2 is a cut away view that illustrates the internal portions of the diaphragm valve 10. FIG. 2 illustrates all of the external portions of the diaphragm valve including inlet fitting 10, outlet fitting 12 first housing component 16, first flange segment 18, second housing component 20, second flange segment 22 and external portion of actuator 26. FIG. 2 further illustrates the cut away portion of the flexible fluoropolymer body. Flexible fluoropolymer body 28 is configured to be attached diaphragm valve 10 between the first flange segment 18 and second flange segment 22. When the diaphragm valve 10 is used in a fluid circuit the flexible fluoropolymer body provides an external structure allowing for a conductive path between the internal and external structure of the diaphragm valve 10. The external structure of the flexible fluoropolymer body may be connected to ground to provide electrostatic mitigation of charge that may be generated by fluid flow in the internal regions of a fluid circuit.

[0034] FIG. 3 is an exploded view that illustrates the principle structure of an embodiment of a diaphragm valve 30. The structure includes an inlet fitting, 32, an outlet fitting 34 and first housing component 36. FIG. 3 further illustrates a flexible fluoropolymer body 38a and 38b configured to be attached between first housing component 36 and second housing component 40. Second housing component 40 also includes the external portion of an actuator 42.

[0035] FIG. 4 is an isometric view of housing component 40 including a flange segment 42, a flexible fluoropolymer body 44, and external portion of an actuator 46. The combination of the flexible fluoropolymer body and external portion of the actuator 46 allows control of fluid in an assembled diaphragm valve by adjusting or controlling the position of the flexible fluoropolymer body.

[0036] FIG. 5 illustrates an embodiment of a diaphragm or flexible fluoropolymer body 50. In this embodiment the flexible fluoropolymer body comprises a conductive fluoropolymer that is molded into a predetermined shape using a selected conductive fluoropolymer to provide an essentially uniform polymeric structure in the molded flexible fluoropolymer body. The conductive fluoropolymer includes a tab 52 which extends to the external portion of an assemble diaphragm valve. When tab 52 is grounded, the conductive fluoropolymer provides a conductive pathway to mitigate static charge that may be generated by fluid flow in the internal portion of the diaphragm valve and fluid flow through a fluid circuit

[0037] FIG. 6 illustrates an embodiment of a diaphragm or flexible fluoropolymer body 60. In this embodiment the flexible fluoropolymer body comprises a conductive fluoropolymer 62 on the perimeter of the flexible fluoropolymer body 60 and a non-conductive fluoropolymer 64 within the internal region of the flexible fluoropolymer body. Flexible fluoropolymer body 60 is molded into a predetermined shape using a selected conductive fluoropolymer and a selected non-conductive fluoropolymer to provide the molded flexible fluoropolymer body 60 having a conductive perimeter portion and a non-conductive internal region. The conductive fluoropolymer perimeter portion includes a tab 66 which extends to the external portion of an assemble diaphragm valve. When tab 66 is grounded, the conductive fluoropolymer perimeter portion provides a conductive pathway to mitigate static charge that may be generated by fluid flow in the internal portion of the diaphragm valve and fluid flow through a fluid circuit.

[0038] FIG. 7 illustrates an embodiment of a diaphragm or flexible fluoropolymer body 70 and a conductive fluoropolymer gasket 72. In this embodiment the flexible fluoropolymer body comprises a non-conductive fluoropolymer body 70. Similarly, conductive fluoropolymer gasket 72 is molded to a predetermined shape using a selected conductive fluoropolymer. The shape of the gasket 72 is configured to correspond to the shape of the perimeter of the flexible fluoropolymer body 70 and the flange segments of a diaphragm valve having a first housing component and second housing component as illustrated, for example, in FIG. 3. The conductive fluoropolymer gasket includes a tab 74 which extends to the external portion of an assemble diaphragm valve. When tab 74 is grounded, the conductive fluoropolymer provides a conductive pathway to mitigate static charge that may be generated by fluid flow in the internal portion of the diaphragm valve and fluid flow through a fluid circuit

[0039] Operative components and diaphragm valves in this disclosure refer to any component or device having a fluid input and a fluid output and that connect with tubing for directing or providing for the flow of fluid. Related and additional components of fluid control systems are illustrated, for example, in U.S. Pat. Nos. 5,672,832; 5,678,435; 5,869,766; 6,412,832; 6,601,879; 6,595,240; 6,612,175; 6,652,008; 6,758,104; 6,789,781; 7,063,304; 7,308,932; 7,383,967; 8,561,855; 8,689,817; and 8,726,935, each of which are incorporated herein by reference, except for express definitions or patent claims contained in the listed documents.

[0040] The fluid control components if this disclosure, such as, for example, a diaphragm comprising a fluoropolymer, may be constructed from conductive and/or non-conductive fluoropolymers including, for example, perfluoroalkoxy alkane polymer (PFA), ethylene and tetrafluoroethylene polymer (ETFE), ethylene, tetrafluoroethylene and hexafluoropropylene polymer (EFEP), fluorinated ethylene propylene polymer (FEP), tetrafluoroethylene p[polymer PTFE), or other suitable polymeric materials. For example, in some embodiments the conductive fluoropolymers may be loaded with conductive material (e.g. a loaded fluoropolymer). This loaded fluoropolymer includes, but is not limited to, a fluoropolymer loaded with carbon fiber, nickel coated graphite, carbon fiber, carbon powder, carbon nanotubes, metal particles, and steel fiber.

[0041] Alternatively, the fluid control components if this disclosure, such as, for example, a diaphragm may be constructed from perfluorinated ionomer particles that are blended with a non-conductive fluoropolymer to form a composite including a non-conductive fluoropolymer matrix and regions of perfluorinated ionomer distributed within the non-conductive fluoropolymer matrix as described above in this disclosure.

[0042] In various embodiments, conductive materials have a resistivity level less than about 1×10.sup.10 ohm-m while non-conductive materials have a resistivity level greater than about 1×10.sup.10 ohm-m. In certain embodiments, conductive materials have a resistivity level less than about 1×10.sup.9 ohm-m while non-conductive materials have a resistivity level greater than about 1×10.sup.9 ohm-m. When the disclosed fluid handling systems are configured for use in ultra-pure fluid handling applications, the fluid control components may be constructed from polymeric materials to satisfy purity and corrosion resistance standards.

[0043] The various additional elements of the operative components and diaphragm valves of this disclosure, in addition to the flexible fluoropolymer body described above, may be constructed from materials including metals, polymeric materials, or loaded polymeric materials. Generally loaded polymeric materials of selected structural elements of the operative components and diaphragm valves may include a polymer that is loaded with steel wire, aluminum flakes, nickel coated graphite, carbon fiber, carbon powder, carbon nanotubes, or other conductive material. In some instances, these elements may have a main portion constructed from non-conductive or low conductive material, such as constructed from various hydrocarbon and non-hydrocarbon polymers such as, but are not limited to, polyesters, polycarbonates, polyamides, polyimides, polyurethanes, polyolefins, polystyrenes, polyesters, polycarbonates, polyketones, polyureas, polyvinyl resins, polyacrylates, polymethylacrylates and fluoropolymers. Exemplary fluoropolymers include, but are not limited to, perfluoroalkoxy alkane polymer (PFA), ethylene tetrafluoroethylene polymer (ETFE), ethylene, tetrafluoroethylene and hexafluoropropylene polymer (EFEP), fluorinated ethylene propylene polymer (FEP), and tetrafluoroethylene polymer (PTFE), or other suitable polymeric materials, and having, for example, a secondary co-extruded conductive portion.

[0044] The operative components and diaphragm valves of this disclosure are suitable for use in fluid circuits having electrostatic mitigation systems. FIG. 8 is a schematic diagram of an exemplary fluid handling system 150. The fluid handling system 150 provides a flow path for fluid to flow from a fluid supply 152 to one or more process stages 156 positioned downstream of the source of fluid supply. Fluid handling system 150 includes a fluid circuit 160 which includes a portion of the flow path of the fluid handling circuit 150. The fluid circuit 160 includes tubing segments 164 and a plurality of operative components 168 that are interconnected via the tubing segments 164. In FIG. 8, the operative components 168 include an elbow shaped fitting 170, T-shaped fitting 172, a valve 174, filter 176, flow sensor 178, and straight fitting 179. However, in various embodiments the fluid circuit 160 can include additional or fewer operative components in number and in type. For example, the fluid circuit 160 could substitute or additionally include pumps, mixers, dispense heads, sprayer nozzles, pressure regulators, flow controllers, or other types of operational components. In assembly, the operative components 168 are connected together by the plurality of tubing segments 164 connecting to the components 168 at their respective tubing connector fittings 186. Connected together, the plurality of tubing segments 164 and operative components 168 provide a fluid passageway through the fluid circuit 160 from the fluid supply 152 and toward the process stages 156.

[0045] The descriptions of the various embodiments of the present disclosure have been presented for purposes of illustration, but are not intended to be exhaustive or limited to the embodiments disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein was chosen to explain the principles of the embodiments, the practical application or technical improvement over technologies found in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.