Welding check valve

Abstract

To provide a check valve that simplifies manufacture while realizing a higher quality seal.SOLUTION: A welded check valve includes a poppet assembly 208, a spring 210, and a disc 212 that contacts the spring. The disc may be held at a position away from a weld 206 when forming the welded check valve. Embodiments may include retention features configured to allow one or more of the poppet assembly and disc to pass the retention features in an assembly orientation, and to retain those elements when they are in an operational orientation. Methods include inserting the poppet assembly, contacting the poppet assembly with a spring, inserting a disc, retaining the disc away from a weld side, and welding the check valve together.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Cross - Reference to Related Applications This application claims the benefit and priority of U.S. Application No. 16 / 683,491, filed on November 14, 2019, the entire disclosure of which is incorporated herein by reference in its entirety.

[0002] This disclosure is directed to check valves, particularly welded check valves.

Background Art

[0003] A check valve allows fluid flow in only one direction and blocks flow in the opposite direction of that allowed flow.

[0004] The assembly of a check valve is typically performed by arranging internal components and threading together a plurality of pieces that form the outer body of the check valve. Machining of the threads can be costly and there is a possibility of media leakage at the threaded joints of the check valve due to temperature changes.

Summary of the Invention

[0005] This disclosure relates to check valves, particularly to polymer components that are welded together to form a check valve. By welding the polymer components of the check valve together, the manufacturing of the check valve components is simplified and a higher - quality seal is obtained. Further, by eliminating threaded connection parts, the possibility of particle generation caused during the assembly of threaded components is reduced. As a result, welded check valves can provide improved performance with respect to high purity, such as in the control of fluid flow during semiconductor manufacturing. The check valve can be welded using thermal welding techniques. Such thermal welding can be made possible by including a holding mechanism that allows the polymer - made check valve components to be held away from the site of the weld or seam. By holding the check valve components away from the weld site, it is possible to prevent the melt - processable components of the check valve from being damaged or adhesively bonded inappropriately during the welding process.

[0006] The embodiments of the check valve include an internal passage and are configured to control the fluid flow through the internal passage. The check valve includes an internal assembly. The internal assembly includes a poppet assembly, a spring that contacts the poppet assembly at a first end, a disk that includes one or more through holes and contacts the spring, a first outer piece having a first opening and an opening on the opposite side of the first opening, and a second outer piece having a second opening and a second opening on the opposite side of the second opening. The second outer piece is connected to the first outer piece by a weld at the opening on the opposite side of the second opening. The first outer piece and the second outer piece define an internal space for holding the internal assembly. A disk holding mechanism is disposed within the internal space and is configured to selectively hold the disk at a position away from the weld within the first outer piece. During the welding process, the internal components of the check valve are advantageously held away from the heat that could cause damage by this mechanism. The internal assembly is configured to block the fluid flow through the internal passage in one direction and allow the flow through the internal passage in the opposite direction.

[0007] In one embodiment, the check valve includes a poppet assembly holding mechanism. The poppet assembly holding mechanism includes a plurality of holding ribs extending from the first outer piece into the internal space, and the holding ribs of the first plurality of holding ribs are separated from each other by a first plurality of gaps, and each of the plurality of gaps is larger than the thickness of the outermost edge of the poppet assembly.

[0008] In one embodiment, the outermost edge of the poppet assembly defines a diameter that is smaller than the diameter of the internal space and larger than the distance between the opposing holding mechanisms of the plurality of holding ribs.

[0009] In one embodiment, the poppet assembly includes a poppet and a poppet assembly disk, the poppet assembly disk includes one or more through holes, and the poppet assembly disk includes the outer edge of the poppet assembly.

[0010] In one embodiment, the plurality of retaining ribs are an even number of retaining ribs, and the plurality of gaps are an even number of gaps.

[0011] In one embodiment, the disk retaining mechanism includes a plurality of retaining ribs extending from a first outer piece into the internal space. The retaining ribs of the second plurality of retaining ribs are separated from each other by a second plurality of gaps, and each of the second plurality of gaps is longer than the thickness of the outermost edge of the poppet assembly and the thickness of the disk.

[0012] In one embodiment, the disk retaining mechanism includes one or more detents formed on the inner surface of the first outer piece. In one embodiment, the detent does not allow the disk to pass when the outer surface of the first outer piece is compressed, and allows the disk to pass when the outer surface of the first outer piece is not compressed.

[0013] In one embodiment, the first outer piece includes an annular groove formed on the inner surface of the first outer piece. In one embodiment, the disk retaining mechanism is a snap ring configured to be inserted into the annular groove, and when the snap ring is inserted into the annular groove, the snap ring has an inner diameter smaller than the outer diameter of the disk. In one embodiment, the disk is configured to be inserted into the annular groove, and the annular groove is the retaining mechanism.

[0014] In one embodiment, the first outer piece, the second outer piece, the poppet assembly, and the spring each include one or more types of fluoropolymers. The fluoropolymer may be melt processable.

[0015] In one embodiment, a method of assembling a check valve includes inserting a poppet assembly into a first outer portion piece of the check valve, where the first outer portion piece includes an inlet of the check valve; pressing a spring against the poppet assembly; inserting a disk such that the disk contacts the spring; and welding the first outer portion piece to a second outer portion piece at a weld joint. During welding, the disk is held in a position away from the weld joint by one or more mechanisms of the first outer portion piece of the check valve.

[0016] In one embodiment, the disk is held by a holding mechanism including a plurality of holding ribs on an inner surface of the first outer portion piece. During insertion of the disk, the disk is rotated such that an outer edge of the disk passes through gaps between the ribs of the plurality of holding ribs. The method further includes rotating the disk such that the disk contacts the plurality of holding ribs.

[0017] In one embodiment, during insertion of the poppet assembly, the poppet assembly is rotated such that an outer edge of the poppet assembly passes through gaps between the ribs of the plurality of holding ribs.

[0018] In one embodiment, during insertion of the poppet assembly, the poppet assembly passes through a second holding mechanism including a plurality of second holding ribs. The method further includes rotating the poppet assembly such that the poppet assembly can contact the plurality of second holding ribs when the poppet assembly moves away from the inlet of the check valve along the axis of the first outer portion piece.

[0019] In one embodiment, the method further includes moving the disk after welding the first outer portion piece to the second outer portion piece such that it is held near the weld by the plurality of holding ribs.

[0020] In one embodiment, welding the first outer portion piece to the second outer portion piece includes thermally welding.

[0021] In one embodiment, thermally welding includes heating the welding surface of the first outer piece using the first surface of the heating paddle, heating the welding surface of the second outer piece using the second surface of the heating paddle, and pressing the welding surface of the first outer piece and the welding surface of the second outer piece together.

[0022] In one embodiment, the method further includes performing a test for flow in a first direction through the first outer piece and a test for flow in a second direction opposite the first direction through the first outer piece after insertion of the disk and before welding.

Brief Description of the Drawings

[0023]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0024] The present disclosure is directed to check valves, particularly welded check valves.

[0025] FIG. 1 shows an exploded view of a welded check valve according to an embodiment. The welded check valve 100 includes a first outer piece 102, a poppet assembly 104, a spring 106, a disk 108, and a second outer piece 110. The first outer piece 102 includes an opening 112 and an aperture 114. The second outer piece 110 includes an opening 116 and an aperture 118. During assembly, the aperture 114 of the first outer piece 102 is welded to the aperture 118 of the second outer piece 110.

[0026] The first outer piece 102 defines a part of the body of the check valve 100. The first outer piece 102 includes an opening 112. In the embodiment shown in FIG. 1, the opening 112 forms the inlet of the check valve 100 and is part of the internal channel through the check valve 100. The first outer piece 102 includes an opening 114. The inner surface of the first outer piece 102 may include a retaining mechanism (not shown) for positioning or restricting the movement of one or more of the poppet assembly 104 or the disk 108.

[0027] The poppet assembly 104 is configured to fit within the first outer piece 104. The poppet assembly 104 includes a poppet 120 and a poppet assembly disk 122.

[0028] In the poppet assembly 104, the poppet 120 is configured to block the flow therethrough when, for example, the poppet 120 is positioned such that it is pressed against the opening 112 by the force from the spring 106 or the pressure brought about by the flow through the check valve 100 towards the opening 112. The poppet 120 is configured to be pushed away when the flow entering through the opening 112 brings about a force greater than the force brought about by the spring 106. The poppet is configured to allow flow in one direction from the opening 112 towards the opening 118 and prevent flow in the opposite direction.

[0029] In the poppet assembly 104, the poppet assembly disk 122 is a circular disk having a diameter such that it can fit inside the first outer piece 102. The poppet assembly disk 122 may have a diameter that allows the poppet assembly 104 to be held within the first outer piece 102 by one or more retaining mechanisms. The poppet assembly disk 122 includes one or more through holes that allow the passage of fluid. The poppet assembly disk may be configured such that the movement of the poppet assembly 104 is restricted by one or more retaining mechanisms provided on the inner surface of the first outer piece 102.

[0030] In one embodiment, the poppet assembly 104 is integrally formed, and the poppet assembly disk is an extension from the poppet. In one embodiment, the poppet assembly 104 includes a poppet assembly disk that is a separate component from the poppet, and the poppet and the poppet assembly disk are fixed to each other via, for example, a mechanical joint, an adhesive, or any suitable connecting method, or a combination thereof.

[0031] Spring 106 can be a spring configured to contact poppet assembly 104 and disk 108. Spring 106 is configured to be compressed between poppet assembly 104 and disk 108. Spring 106 presses poppet assembly 104 against opening 112 when the force acting on poppet assembly 104 is not opposed. The force by which spring 106 presses poppet assembly 104 may be a small force that is easily overcome by the pressure of the flow through opening 112. It is understood that one of ordinary skill in the art can select a spring force appropriate for the operation of the check valve. In one embodiment, spring 106 can be selected such that a flow from opening 112 that provides a pressure of less than about 1 psi compresses spring 106 and moves poppet assembly 104 to allow flow through check valve 102. Spring 106 can be a molded polymer spring.

[0032] Disk 108 holds spring 106 and is used to position spring 106 so that spring 106 presses on poppet assembly 104. Disk 108 includes one or more through holes that allow fluid to pass through disk 108. Disk 108 is configured to fit within first outer portion 102. In one embodiment, disk 108 is configured to be held by a retaining mechanism disposed within first outer portion 102. In one embodiment, disk 108 has an outer diameter that is smaller than the diameter within first outer portion 102 but larger than the distance between two opposing points on one or more retaining mechanisms within first outer portion 102.

[0033] The second outer piece 110 is combined with the first outer piece 102 to form the body of the check valve 100. The second outer piece 110 includes an opening 116 and an opening 118. In certain embodiments, the opening 116 is the outlet of the check valve. The opening 118 is at the end of the second outer piece opposite the opening 116. The opening 118 can be surrounded by a welding surface.

[0034] During assembly, the opening 114 of the first outer piece 102 is welded to the opening 118 of the second outer piece 110. Prior to welding, the ends 114 and 118 can each include a flat welding surface, and the welding surfaces can have corresponding sizes and shapes. In certain embodiments, the welding surfaces at the ends 114 and 118 are aligned with each other such that they are in complete contact with each other. The weld can be, for example, a thermal weld. The weld can be formed by gripping each of the first outer piece 102 and the second outer piece 104, for example, via a clamp or a vise, heating each of the ends 114 and 118, for example, using a heated paddle, aligning the ends 114 and 118 with each other, and pressing the heated ends 114 and 118 together. In certain embodiments, after welding the ends 114 and 118, the disk 108 can be released from a set of retaining mechanisms within the first outer piece 102. An example of a thermal welding process is disclosed in U.S. Patent No. 4,929,293, which is hereby incorporated by reference in its entirety.

[0035] In some embodiments, all components of the check valve 100 can be made of a polymeric material. In some embodiments, all components of the check valve 100 can be made of the same polymeric material. In some embodiments, at least some of the components of the check valve 100 can be made from different fluoropolymers. In some embodiments, the polymeric material is a fluoropolymer. Examples of fluoropolymers used to form the components include, but are not limited to, perfluoroalkoxy alkane polymers (PFA), ethylene tetrafluoroethylene polymers (ETFE), ethylene tetrafluoroethylene hexafluoropropylene polymers (EFEP), polychlorotrifluoroethylene (PCTFE), and fluorinated ethylene propylene polymers (FEP), all of which are melt processable. In addition to providing a non-corrosive and inert structure, many fluoropolymers, such as PFA, are injection moldable and extrudable. In one preferred embodiment, the fluoropolymer is a perfluoroalkoxy alkane polymer (PFA). In other embodiments, the fluoropolymer can be polytetrafluoroethylene (PTFE) or tetrafluoroethylene polymer (PTFE) or modified tetrafluoroethylene polymer (TFM) which is not melt processable but is compression moldable and machinable.

[0036] Figure 2 shows a cross-sectional view of a check valve 200 according to an embodiment. In the embodiment shown in Figure 2, a first outer piece 202 is connected to a second outer piece 204 at a weld 206. The first outer piece 202 and the second outer piece 204 define an internal space that houses a poppet assembly 208, a spring 210, and a disk 212. The inner surface of the first outer piece 202 includes a poppet assembly retaining mechanism 214, a disk retaining mechanism 216, and a weld disk retaining mechanism 218.

[0037] The first outer piece 202 is part of the body of the check valve 200. The first outer piece 202 includes an opening 220 at one end and an opening 222 at the opposite end. The opening 222 can be surrounded by a welding surface. The first outer piece 202 has an internal space between the opening 220 and the opening 222. This internal space is part of the internal passage through the check valve 200. The internal space is defined by the inner surface 224 of the first outer piece.

[0038] The second outer piece 204 is another part of the body of the check valve 200. The second outer piece 204 includes an opening 226 at one end and an opening 234 at the opposite end.

[0039] The weld 206 connects the first outer piece 202 and the second outer piece 204 such that they define the internal space. An internal assembly including a poppet assembly 208, a spring 210, and a disk 212 is received in the internal space. The weld can be any suitable weld that connects the first outer piece 202 and the second outer piece 204. Suitable welds can include, for example, a thermal weld or an ultrasonic weld. In one embodiment, the weld 206 is a thermal weld.

[0040] The poppet assembly 208 can include a poppet 228 and a poppet assembly disk 230. In one embodiment, the poppet 228 and the poppet assembly disk 230 are separate components that are connected to each other by, for example, a mechanical joint, an adhesive, or one or more of any other suitable methods for fixing components to each other.

[0041] In the embodiment shown in FIG. 2, the poppet 228 may include a lip 232 extending from the outer peripheral portion of the poppet 228 toward the opening 220. The lip 232 may form a sealing surface when the poppet 228 obstructs the flow toward its opening 220. The lip 232 may be flexible to form the sealing surface. The lip 232 may be configured to join with the inner surface of the first outer piece 202 to form a sealing portion that prevents fluid flow through the poppet 228 toward the opening 220. The poppet 228 may have a diameter greater than the diameter of the channel to the opening 220 in the direction in which the poppet 228 restricts the flow. When the flow comes from the opening 220 and is directed toward the opening 226, the flow can apply a pressure to the poppet such that the poppet assembly moves toward the opening 226 and compresses the spring 210. Thereby, the poppet assembly is positioned such that the flow from the opening 220 can pass through the poppet 228. This flow then passes through the through holes formed in the poppet assembly disk 230 and the disk 212, passes through the internal space within the check valve 200, and reaches the opening 226.

[0042] The poppet assembly disk 230 is a circular disk having a diameter such that it can fit inside the first outer piece 202. The poppet assembly disk 230 may have a diameter that allows the poppet assembly 208 to be held by one or more poppet assembly retaining mechanisms 214 when in the operating position. The poppet assembly disk 230 includes one or more through holes that allow fluid passage. The poppet assembly disk 230 may be configured such that the poppet assembly 208 can shift in a direction such that the poppet assembly 208 moves toward or away from the opening 226 as viewed from the opening 220. The direction of movement of the poppet assembly 208 may be the direction of fluid flow through the poppet assembly 208 in the internal space of the check valve 200. The movement of the poppet assembly 208 may be restricted by one or more poppet assembly retaining mechanisms 214 provided on the inner surface 224 of the first outer piece 202.

[0043] Spring 210 is a spring configured to contact poppet assembly 208 and disk 212. Spring 210 is configured to push poppet assembly 208 to block opening 220 when there is no opposing force. The force by which spring 210 pushes poppet assembly 208 may be a small force that can be easily overcome by the pressure of the flow passing through opening 220. Spring 210 may be a molded polymer spring.

[0044] Disk 212 secures spring 210 so that spring 210 can apply a force to poppet assembly 208. Disk 212 is maintained in a predetermined position by disk retaining mechanism 216. Disk 212 includes one or more through holes configured to allow fluid to pass through disk 212. In some embodiments, disk 212 is configured to be retained by disk retaining mechanism 216. In some embodiments, disk 212 has an outer diameter that is smaller than the diameter of the internal space within first outer portion 202, but larger than the distance between two points of disk retaining mechanism 216 that face each other with respect to the center line of the internal space within first outer portion piece 202.

[0045] The inner surface 224 of the first outer piece 202 includes a poppet assembly retaining mechanism 214. In the embodiment shown in FIG. 2, the poppet assembly retaining mechanism is integrally formed with the inner surface 224 of the first outer piece 202 and extends inwardly from that surface. In this embodiment, the poppet assembly retaining mechanism may be two or more ribs, and the ribs are separated by two or more gaps therebetween. The ribs may project inwardly such that the distance between points on the ribs that face each other with respect to the center of the internal space within the first outer piece 202 is less than the outer diameter of the poppet assembly disk 230. In certain embodiments, the poppet assembly retaining mechanism 214 may be a snap ring or may be included on a snap ring that is inserted into a groove formed in the inner surface 224 of the first outer piece 202. The poppet assembly retaining mechanism 214 may be closer to the opening 220 and farther from the opening 226 of the first outer piece 202 than other retaining mechanisms such as the disk retaining mechanism 216 or the welded disk retaining mechanism 218.

[0046] In the embodiment shown in FIG. 2, the disk retaining mechanism 216 is included in the inner surface 224 of the first outer piece 220. The disk retaining mechanism 216 may be integrally formed with the first outer piece 202. In this embodiment, the disk retaining mechanism may be two or more ribs, and the ribs are separated by two or more gaps therebetween. The ribs may project inwardly such that the distance between points on the ribs that face each other with respect to the center of the internal space within the first outer piece 202 is less than the outer diameter of the disk 212. In certain embodiments, the disk retaining mechanism 216 may be a snap ring or may be included on a snap ring that is inserted into a groove formed in the inner surface 224 of the first outer piece 202. The disk retaining mechanism 216 may be closer to the opening 226 and farther from the opening 220 of the first outer piece 202 than other retaining mechanisms such as the poppet assembly retaining mechanism 214 or the welded disk retaining mechanism 218.

[0047] FIG. 2 shows an optional welding disk holding mechanism 218. In the embodiment shown in FIG. 2, the welding disk holding mechanism 218 is an annular ridge protruding from the inner surface 224 of the first outer part piece 202, which is disposed between the poppet assembly holding mechanism 214 and the disk holding mechanism 216 in the longitudinal direction of the first outer part piece 202. In certain embodiments, the welding disk holding mechanism 218 is a detent. In certain embodiments, the welding disk holding mechanism 218 is sized to provide an interference fit, in which case, when a force is applied to the disk 212, the disk 212 can be pushed to the opposite side of the welding disk holding mechanism 218. In this embodiment, when an external force exceeding the spring 210 is not applied to the disk 212, the interference fit prevents the disk 212 from passing through the welding disk holding mechanism 218. In certain embodiments, the welding disk holding mechanism 218 is sized such that the disk 212 can pass through the welding disk holding mechanism 218 when no pressure is applied to the outer part of the first outer part piece 202, but when pressure is applied to the outer part of the first outer part piece 202, the welding disk holding mechanism 218 provides sufficient frictional force to maintain the disk 212 in a predetermined position or to prevent the passage of the disk 212 toward the opening 222. The welding disk holding mechanism 218 can be used to secure the disk 212 at a position farther from the weld during welding, and then, when the check valve 200 is assembled and ready for use, release the disk 212 to enable movement of the disk 212 to the disk holding mechanism 216.

[0048] The internal assembly, including the poppet assembly 208, spring 210, and disk 212, is configured to block fluid flow through the internal passage in one direction and allow flow through the internal passage in the opposite direction. In one embodiment, when fluid is flowing from the opening 220 of the first outer piece 202 towards the opening 226 of the second outer piece 204, a pressure is applied by the fluid flow that overcomes the spring force provided by the spring 210, as a result of which the poppet assembly 208 is moved away from the opening 220 and towards the opening 226. Thereby the poppet 228 is positioned so as not to block the flow from the opening 220, and the flow passes through the poppet 228, through the through holes formed in the poppet assembly disk 230 and the disk 212, and reaches the opening 226. When the flow is in the opposite direction, from the opening 226 towards the opening 220, the spring 210 acts on the poppet assembly 208 to position the poppet 228 to block the flow to the opening 220. The pressure of the flow from the opening 226 towards the opening 220 also presses the poppet 228, sealing the poppet 228 in place and preventing flow to the opening 220. The embodiment shown in Figure 2 thus results in flow in only one direction through the internal space within the check valve 200 and blocks flow in the opposite direction.

[0049] In some embodiments, all components of the check valve 200 can be made of a polymeric material. In some embodiments, all components of the check valve 200 can be made of the same polymeric material. In some embodiments, at least some of the components of the check valve 200 can be made from different fluoropolymers from each other. In some embodiments, the polymeric material is a fluoropolymer. Examples of fluoropolymers used to form the components include, but are not limited to, perfluoroalkoxy alkane polymers (PFA), ethylene tetrafluoroethylene polymers (ETFE), ethylene tetrafluoroethylene hexafluoropropylene polymers (EFEP), polychlorotrifluoroethylene (PCTFE), and fluorinated ethylene propylene polymers (FEP), all of which are melt processable. In addition to providing a non-corrosive and inert structure, many fluoropolymers, such as PFA, are injection moldable and extrudable. In one preferred embodiment, the fluoropolymer is a perfluoroalkoxy alkane polymer (PFA). In other embodiments, the fluoropolymer can be polytetrafluoroethylene (PTFE), or tetrafluoroethylene polymer (PTFE), or modified tetrafluoroethylene polymer (TFM), which is not melt processable but is compression moldable and machinable.

[0050] Figures 3A-3H illustrate the steps of an example of inserting a poppet assembly 302, a spring 304, and a disk 306 into a first outer portion piece 300 of a check valve according to an embodiment.

[0051] Figure 3A shows a first outer portion piece 300 of a check valve provided in a method of assembling a valve according to an embodiment. Within the first outer portion piece 300, a poppet assembly retaining mechanism 308, a disk retaining mechanism 310, and a weld disk retaining mechanism 312 can be seen.

[0052] In the embodiment shown in FIG. 3A, the poppet assembly retaining mechanism 308 includes a plurality of ribs formed in the first outer piece 300 and disposed toward an opening that is farther from the open end. The plurality of ribs includes a plurality of gaps extending inwardly from the inner surface of the first outer piece 300. In certain embodiments, the poppet assembly retaining mechanism 308 may be at least two ribs, and at least two gaps are formed between the at least two ribs. The ribs may be integrally formed with the first outer piece 300. Each of the plurality of gaps is sized such that the poppet assembly 302 can pass through the poppet assembly retaining mechanism 308 when the poppet assembly 302 is rotated relative to its operating position. In certain embodiments, the ribs may be included on a snap ring inserted into a groove formed in the first outer piece 300. In certain embodiments, the poppet assembly retaining mechanism 308 is replaced with a groove configured to receive the snap ring, and the inner diameter of the snap ring is smaller than the inner diameter of the internal space within the first outer piece 300.

[0053] In the embodiment shown in FIG. 3A, the disk retaining mechanism 310 includes a plurality of ribs disposed toward the open end and farther from an opening formed in the first outer piece 300. The plurality of ribs are separated by a plurality of gaps extending inwardly from the inner surface of the first outer piece 300. In certain embodiments, the disk retaining mechanism 310 may be at least two ribs, and at least two gaps are formed between the at least two ribs. Each of the plurality of gaps is sized such that the poppet assembly 302 and the disk 306 can each pass through the disk retaining mechanism 310 when the poppet assembly 302 and the disk 306 are rotated relative to their operating positions. The ribs may be integrally formed with the first outer piece 300. In certain embodiments, the ribs may be included on a snap ring inserted into a groove formed in the first outer piece 300. In certain embodiments, the disk retaining mechanism 310 is replaced with a groove configured to receive the snap ring, and the inner diameter of the snap ring is smaller than the inner diameter of the internal space within the first outer piece 300.

[0054] The embodiment shown in FIG. 3A further includes an optional welding disk holding mechanism 312. In the embodiment shown in FIG. 3A, the welding disk holding mechanism 312 is a small protrusion from the inner surface of the first outer piece 300 that is disposed between the poppet assembly holding mechanism 308 and the disk holding mechanism 310. The welding disk holding mechanism 312 allows the disk 308 to pass through the welding disk holding mechanism 312 when no pressure is applied to the outer portion of the first outer piece 300, but when pressure is applied to the outer portion of the first outer piece 300, the welding disk holding mechanism 312 provides sufficient frictional force to maintain the disk 308 in a predetermined position or to prevent the disk 308 from passing toward the open end of the first outer piece 300. The welding disk holding mechanism 312 is used to fix the disk 308 at a position farther from the weld during welding, and then, when the check valve is assembled and ready for use, it is possible to allow the disk 308 to advance to the disk holding mechanism 310. The position of the disk when maintained by the welding disk holding mechanism 312 can be seen in FIG. 3H.

[0055] FIG. 3B shows the insertion of the poppet assembly 302 into the first outer piece 300. The poppet assembly is rotated so that the poppet assembly disk can pass through the gap between the disk holding mechanisms 310 and the gap between the poppet assembly holding mechanisms 308. As a result, the poppet assembly can be positioned facing the opening formed in the first outer piece 300 on the opposite side of the open end of the first outer piece 300.

[0056] Figures 3C and 3D show the rotation of the poppet assembly 302 to the operating position. The poppet assembly 302 is in the process of rotation in Figure 3C and is fully rotated in Figure 3D. The poppet assembly in Figure 3D is in the operating position, in which case the plane of the disk included in the poppet assembly 302 is perpendicular to the direction in which fluid will enter through the opening formed in the first outer piece 300. In the operating position, the poppet assembly 302 can be slidable between a closed position where the poppet covers the fluid path to the opening of the first outer piece 300 and a fully open position where the poppet assembly contacts the poppet assembly retaining mechanism 308.

[0057] In embodiments where the poppet assembly retaining mechanism 308 includes or is a snap ring, the poppet assembly 302 can be installed in the first outer piece 300 in the operating position shown in Figure 3D without rotating it as shown in Figures 3B and 3C, and then the snap ring can be inserted into the first outer piece 300 and snap - engaged into the groove.

[0058] Figure 3E shows the state of installing a spring so as to contact the poppet assembly. The spring is directly inserted into the first outer piece 300, and the end of the spring 304 contacts the poppet assembly 302.

[0059] Figure 3F shows the insertion of the disk 306 into the check valve. The insertion of the disk 306 shown in Figure 3F is performed while the spring 304 is in contact with the poppet assembly 302. The disk is rotated so that the outermost edge of the disk can pass through the gap of the disk retaining mechanism 310 during insertion.

[0060] Figure 3G shows the disk 306 in the operating position held by the disk retaining mechanism 310. The disk is rotated so that the outermost edge of the disk 306 can contact the disk retaining mechanism 310. In the operating position, the spring 304 presses the disk 306 against the disk retaining mechanism 310. As a result, the disk 306 is pressed against and positioned by the disk retaining mechanism 310, and the spring 304 can exert a force on the poppet assembly 302.

[0061] In embodiments where the disk retaining mechanism 310 is or includes a snap ring, the disk 306 can be placed pressed against the spring 304 in the operating position shown in FIG. 3, and then the snap ring can be inserted into the groove at the position of the disk retaining mechanism 310.

[0062] FIG. 3H shows the disk 306 moved to an optional position for welding, farther from the welding surface on the end of the first outer piece 300. The first outer piece 300 and the components held therein can then be welded to a second outer piece (not shown) to form a check valve. To achieve the position of the disk 306 shown in FIG. 3H, the disk 306 in the operating position shown in FIG. 3G is pushed toward the poppet assembly 304 and maintained in that position with the spring compressed. An optional welded disk retaining mechanism 312 can provide an interference fit with the disk 306. In some embodiments, by applying a force to the disk 306, the disk 306 can be pushed beyond the optional welded disk retaining mechanism 312. In some embodiments, when the disk 306 is not subject to forces other than those provided by the spring 304, the interference fit of the retaining mechanism 312 can hold the disk 306. In some embodiments, the interference fit between the optional welded disk retaining mechanism 312 and the disk 306 may be affected by an external force on the first outer piece 300. In this embodiment, while the disk 306 is in this position, pressure is applied to the outer surface of the first outer piece 300 via a clamp, such as a clamp used to secure the piece for welding, for example. In that case, while pressure is applied to the outer surface with the spring 304 applying a force to move the disk 306 toward the welded disk retaining mechanism 312, the disk 306 may be released, but in that case, the disk 306 is held by friction or mechanical interference while pressure is applied to the outer surface. The disk 306 may be able to pass through the welded disk retaining mechanism 312 when the pressure is removed and may instead be held by the disk retaining mechanism 310.

[0063] Figure 4 shows a flowchart of a method 400 according to an embodiment. The method 400 includes inserting a poppet assembly into a first outer piece of a check valve at 402, installing a spring by pressing it against the poppet assembly at 404, and inserting a disk at 406. Optionally, the method 400 includes moving the disk so that the disk is held farther from its operating position than from the weld at 408. The method 400 further includes welding the first outer piece to a second outer piece at a welded joint at 410. In some embodiments, the method 400 optionally includes performing a flow test in a first direction through the first outer piece at 412 and a flow test in a second direction opposite the first through the first outer piece at 414 after insertion of the disk and before welding.

[0064] Inserting a poppet assembly into a first outer piece of a check valve at 402 includes placing the poppet assembly within the first outer piece. In some embodiments, the poppet assembly can be rotated such that the outermost edge of the poppet assembly passes, such as by passing through a gap between ribs included in a poppet assembly retaining mechanism. In this embodiment, the poppet assembly can further pass through a disk retaining mechanism in the same manner. In this embodiment, the poppet assembly can then be rotated to its operating position before installing the spring by pressing it against the poppet assembly at 404. The operating position can include the plane of the disk of the poppet assembly that is perpendicular to the direction of flow through the check valve. In some embodiments, the poppet assembly is oriented at its operating position upon insertion, and a snap ring is inserted into a groove to hold the poppet assembly during use before installing the spring by pressing it against the poppet assembly at 404.

[0065] The spring is installed by pressing it against the poppet assembly at 404. The ends of the spring can be configured to engage a mechanism on the poppet assembly. The spring can be inserted into the first outer piece through an open end of the first outer piece. The spring then also contacts the disk that is inserted at 406.

[0066] A disk is inserted at 406. The disk inserted at 406 contacts a spring inserted at 404. In some embodiments, inserting the disk at 406 includes rotating the disk so that the outermost edge of the disk can pass through the disk holding mechanism, such as by passing through a gap between ribs included in the disk holding mechanism. In this embodiment, the disk can be rotated to an operating position where the disk is maintained by the disk holding mechanism. In embodiments where the disk holding mechanism includes or is a snap ring, the disk can be inserted in the operating position and maintained within a first outer piece, and then the snap ring can be inserted and positioned within a groove such that the disk holding mechanism contacts the disk when the snap ring is in the groove and the disk is released.

[0067] Optionally, method 400 includes moving the disk such that the disk is held farther from the operating position of the disk than from the weld at 408. In this optional step, the disk is moved toward a poppet assembly and can pass through a weld disk holding mechanism. The disk is maintained in that position while pressure is applied. In some embodiments, pressure is applied via a clamp that holds a first outer portion of a check valve during welding 410. This pressure causes the weld disk holding mechanism to move into place, resulting in the application of a frictional force or mechanical interference that holds the disk at a position farther from the weld than from the disk holding mechanism.

[0068] Method 400 includes welding a first outer piece to a second outer piece at a weld joint 410 to form a check valve. The weld may be a thermal weld. The thermal weld may be a thermal welding technique suitable for joining polymer materials such as, for example, fluoropolymers. In some embodiments, the thermal weld may be performed by heating a weld surface surrounding an opening at an end of the first outer piece and the second outer piece, positioning the heated weld surfaces to face each other, and pressing the weld surfaces against each other to form a weld joint. In some embodiments, the weld surfaces are heated on both sides of a paddle that has been heated prior to welding. The temperature at which the weld surfaces are heated may be a suitable welding temperature for one or more of the materials used at the weld surface. By welding the first outer piece to the second outer piece 410, an internal space is defined within the welded first and second outer pieces, which houses an internal assembly including a poppet assembly, a spring, and a disk. In some embodiments, welding the first outer piece to the second outer piece includes heating the weld surfaces to a temperature above the melting point of the material of the weld surfaces. In some embodiments, the temperature applied to the weld surfaces may be between 1250°F and 2000°F. In some embodiments, welding the first outer piece to the second outer piece can be automated by a machine that holds the assembled first and second outer pieces, heats the weld surfaces with a paddle for a predetermined time, removes the paddle, and presses the weld surfaces together.

[0069] In one embodiment, method 400 optionally includes performing a test 412 of flow in a first direction through a first outer piece and a test 414 of flow in a second, opposite direction through the first outer piece, after inserting the disk 406 and before welding 410. The first direction can be a direction from an opening included in the first outer piece toward an opening at an end of the first outer piece opposite the opening. The test of flow in the first direction can be tested by providing such flow in the first direction 412. The check valve is functioning properly when flow in the first direction is allowed to pass through the poppet assembly, spring, and disk. The test of flow in the second direction 414 can be tested by providing flow in the opposite direction. The check valve

[0070] Aspect It is understood that any one of aspects 1 to X can be combined with any one of aspects Y to Z.

[0071] Aspect 1. A check valve including an internal passage, the check valve being configured to control fluid flow through the internal passage, the check valve (a) an internal assembly, (i) a poppet assembly, (ii) a spring contacting the poppet assembly at a first end, and (iii) a disk including one or more through-holes contacting the spring, the internal assembly having, (b) a first outer piece having a first opening and a first opening opposite the first opening, and (c) a second outer piece having a second opening and a second opening opposite the second opening, the first outer piece and the second outer piece being connected by a weld at the first opening and the second opening to define an internal space for holding the internal assembly, the check valve further (d) including a disk holding mechanism disposed within the internal space and configured to selectively hold the disk at a position away from the weld within the internal space. The internal assembly is a check valve configured to block a fluid flow passing through the internal passage in one direction and allow a flow passing through the internal passage in the opposite direction.

[0072] Aspect 2. Comprising a poppet assembly retaining mechanism, the poppet assembly retaining mechanism Comprises a plurality of retaining ribs extending from a first outer part piece into the internal space, and the retaining ribs of the first plurality of retaining ribs are separated from each other by a first plurality of gaps, Each of the plurality of gaps is larger than the thickness of the outermost edge of the poppet assembly, the check valve according to Aspect 1.

[0073] Aspect 3. The outermost edge of the poppet assembly defines a diameter that is smaller than the diameter of the internal space and larger than the distance between the opposing retaining mechanisms of the plurality of retaining ribs, the check valve according to Aspect 2.

[0074] Aspect 4. The poppet assembly comprises a poppet and a poppet assembly disk, the poppet assembly disk includes one or more through holes, and the poppet assembly disk includes the outer edge of the poppet assembly, the check valve according to Aspect 2 or 3.

[0075] Aspect 5. The plurality of retaining ribs are an even number of retaining ribs, and the plurality of gaps are an even number of gaps, the check valve according to any one of Aspects 2 to 4.

[0076] Aspect 6. The disk retaining mechanism comprises a plurality of retaining ribs extending from a first outer part piece into the internal space, and the retaining ribs of the second plurality of retaining ribs are separated from each other by a second plurality of gaps, and each of the second plurality of gaps is longer than the thickness of the outermost edge of the poppet assembly and the thickness of the disk, the check valve according to any one of Aspects 1 to 5.

[0077] Aspect 7. The check valve according to any one of Aspects 1 to 6, wherein the disk holding mechanism includes one or more detents formed on the inner surface of the first outer piece.

[0078] Aspect 8. The check valve according to Aspect 7, wherein the detent does not allow the disk to pass when the outer surface of the first outer piece is compressed, and allows the disk to pass when the outer surface of the first outer piece is not compressed.

[0079] Aspect 9. The check valve according to any one of Aspects 1 to 8, wherein the first outer piece includes an annular groove formed on the inner surface of the first outer piece.

[0080] Aspect 10. The check valve according to Aspect 9, wherein the disk holding mechanism is a snap ring configured to be inserted into the annular groove, and when the snap ring is inserted into the annular groove, the snap ring has an inner diameter smaller than the outer diameter of the disk.

[0081] Aspect 11. The check valve according to Aspect 9, wherein the disk is configured to be inserted into the annular groove, and the annular groove is a holding mechanism.

[0082] Aspect 12. The check valve according to any one of Aspects 1 to 11, wherein the first outer piece, the second outer piece, the poppet assembly, and the spring each include one or more fluoropolymers.

[0083] Aspect 13. A method of assembling a check valve, inserting a poppet assembly into a first outer piece of the check valve, wherein the first outer piece includes an inlet of the check valve; installing a spring by pressing it against the poppet assembly; inserting a disk so that the disk contacts the spring; welding the first outer piece to a second outer piece at a welded joint. A method in which, during welding of the disk, the disk is held at a position away from the welded joint by one or more mechanisms of the first outer piece of the check valve.

[0084] Aspect 14. The disk is held by a holding mechanism including a plurality of holding ribs on the inner surface of the first outer piece. During insertion of the disk, the disk is rotated such that the outer edge of the disk passes through the gaps between the ribs of the plurality of holding ribs. The method further includes rotating the disk such that the disk contacts the plurality of holding ribs, the method according to aspect 13.

[0085] Aspect 15. During insertion of the poppet assembly, the poppet assembly is rotated such that the outer edge of the poppet assembly passes through the gaps between the ribs of the plurality of holding ribs, the method according to aspect 14.

[0086] Aspect 16. During insertion of the poppet assembly, the poppet assembly passes through a second holding mechanism. The second holding mechanism includes a plurality of second holding ribs. The method further includes rotating the poppet assembly such that the poppet assembly can contact the plurality of second holding ribs when the poppet assembly moves away from the inlet of the check valve along the axis of the first outer piece, the method according to aspect 15.

[0087] Aspect 17. After welding the first outer piece to the second outer piece, the method further includes moving the disk such that it is held near the welded joint by the plurality of holding ribs, the method according to any one of aspects 13 to 16.

[0088] Aspect 18. Welding the first outer piece to the second outer piece includes thermally welding, the method according to any one of aspects 13 to 17.

[0089] Aspect 19. Thermally welding includes: heating the welding surface of the first outer piece using the first surface of the heating paddle; heating the welding surface of the second outer piece using the second face of the heating paddle; and pressing the welding surface of the first outer piece and the welding surface of the second outer piece together, the method according to aspect 18.

[0090] Aspect 20. further comprising performing a test of flow in a first direction through the first outer piece and a test of flow in a second direction opposite the first through the first outer piece after insertion of the disc and before welding, the method according to any one of aspects 13 to 19.

[0091] The examples disclosed in this application should be considered illustrative and not restrictive in any way. The scope of the present invention is shown not by the above description but by the appended claims, and it is intended that all modifications made within the equivalent meaning and scope of the claims be included therein.

Claims

1. A check valve including an internal passage, the check valve being configured to control fluid flow through the internal passage, the check valve comprising: (a) an internal assembly, (i) a poppet assembly, (ii) a spring contacting the poppet assembly at a first end, and (iii) a disk including one or more through holes contacting the spring, the internal assembly having; and (b) a first outer piece having a first opening and a first aperture opposite the first opening; and (c) a second outer piece having a second opening and a second aperture opposite the second opening, the first outer piece and the second outer piece being connected by a weld at the first aperture and the second aperture to define an internal space for holding the internal assembly, the check valve further comprising: (d) a disk holding mechanism disposed within the internal space and configured to selectively hold the disk at a position away from the weld within the internal space; and (e) a poppet assembly holding mechanism, the poppet assembly holding mechanism comprising: a plurality of holding ribs extending from the first outer piece into the internal space, the holding ribs of the plurality of holding ribs being separated from each other by a plurality of gaps, each of the plurality of gaps being larger than the thickness of the outermost edge of the poppet assembly, the internal assembly being configured to block fluid flow through the internal passage in one direction and allow flow through the internal passage in the opposite direction, a check valve.

2. The check valve according to claim 1, wherein the disk holding mechanism comprises a second plurality of holding ribs extending from the first outer piece into the internal space, the holding ribs of the second plurality of holding ribs being separated from each other by a second plurality of gaps, each of the second plurality of gaps being longer than the thickness of the outermost edge of the poppet assembly and the thickness of the disk.

3. The check valve according to claim 1, wherein the disk holding mechanism comprises one or more ribs formed on an inner surface of the first outer piece.

4. The check valve according to claim 1, wherein the first outer piece includes an annular groove formed on an inner surface of the first outer piece.

5. The check valve according to claim 4, wherein the disk holding mechanism includes one or more snap rings configured to be inserted into the annular groove formed on the inner surface of the first outer partial piece.

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