valve

Abstract

A valve is described that includes a housing (20), a flow path connecting an inlet and an outlet in flow communication, a valve seat (28) positioned within the flow path, and a valve body displaceable between a closed position and an open position. The valve body includes a resiliently deformable elastomeric seal (38) having (i) a contact surface (74) complementary to and abutting the valve seat, and (ii) a protrusion (84) extending radially outward at an upper portion of the protrusion. The valve also has a retainer with an inwardly projecting lip defining a recess for receiving the protrusion therein to assist in lifting the elastomeric seal.

Description

Technical Field

[0001] The present invention relates to a valve. More specifically, it relates to a valve and a pump system using the valve.

Background Art

[0002] One type of valve includes an annular valve seat and a valve body displaceable between an open position that permits flow of a medium through the valve and a closed position that inhibits flow of the medium through the valve. The valve body includes an annular contact surface of complementary shape that abuts against the valve seat when the valve body is in its closed position. In certain applications, the complementary surfaces of the valve seat and the valve body are formed of metal. In some applications, an elastomeric valve ring is installed on the valve body to seal against the valve seat when the valve is in the closed position.

[0003] This arrangement generally operates well, but problems can occur when the valve body has to be opened in the presence of a large pressure differential (which may occur against an operating valve). When the pressure on the side of the valve body having the elastomeric valve ring is significantly higher (e.g., 1 MPa (10 bar) or more) than the pressure on the opposite side of the valve body of the elastomeric valve ring, when the valve body is displaced away from its closed position towards its open position, due to the pressure differential across the elastomeric valve ring, it tends to be biased towards the valve seat and deform (stretch or extrude) so as to remain in contact with the valve seat, giving the impression of being "stuck" to the valve seat. This extrusion can lead to damage to the elastomeric valve ring or, in some cases, to partial or complete detachment from the valve body. This can also have an adverse effect on the operation of the valve and the lifespan of the elastomeric valve ring. The magnitude of the pressure differential that causes problems can depend on the size of the elastomeric valve ring and the tensile force applied to the valve body that operates to open the valve.

[0004] One potential application where this might occur is in pressure exchange chamber ("PEC") pumping systems where a valve must be opened despite a large pressure difference across the valve (e.g., 1 MPa (10 bar) or more). A PEC pump system typically includes one or more pipes, each having a valve arrangement for the medium or fluid being delivered at one end and a valve arrangement for the drive fluid at the other end. Each pipe and its associated valve combination defines the PEC.

[0005] There are numerous other applications where valves are used to regulate the flow of a medium in high-pressure applications where this problem could potentially occur. For example, another application where this could occur is in hydraulically driven positive displacement pumps that use actuating valves. There may also be applications where check valves are used.

[0006] One object of one embodiment of the present invention is to provide a means that may at least improve the problem, or to provide a useful alternative. [Overview of the Initiative] [Means for solving the problem]

[0007] This summary of the invention is provided to introduce a selection of concepts that will be further described below in embodiments for carrying out the invention. This summary of the invention is not intended to identify essential features of the claimed subject matter, nor is it intended to be used as an aid to limit the scope of the claimed subject matter.

[0008] In this application, sequential numbers (first, second, third, etc.) are arbitrarily assigned herein and used to distinguish parts, and do not indicate any particular order, sequence, or importance.

[0009] According to a first aspect of the present invention, a valve is provided comprising: a housing; an inlet connected to the housing; an outlet connected to the housing at a position spaced apart from the inlet; a flow path connecting the inlet and the outlet in a flow-communication manner; a valve seat positioned within the flow path; a valve body displaceable between a closed position that obstructs the flow of a medium through the flow path and an open position that allows the flow of a medium through the flow path, the valve body including an elastomer seal having (i) a contact surface that is complementary to and in contact with the valve seat when the valve body is in its closed position, and (ii) a projection extending radially outward in the upper portion of the projection; and a retainer having an inwardly projecting lip defining a recess for accommodating the projection in order to assist in lifting the elastomer seal, thereby minimizing or preventing sticking or deformation when the valve body is displaced toward its open position away from its closed position.

[0010] The valve may include an actuator, which allows the valve body to be displaced between its open and closed positions. Optionally, the actuator can be moved hydraulically, pneumatically, or electrically. One suitable embodiment is a linear hydraulic actuator.

[0011] The valve seat may be an integral part of the support (such as the housing) or a removable part that can be replaced when worn.

[0012] The valve seat may be annular or arranged around a flow path, so that the flow path extends through the valve seat. When the valve body is in the closed position, the valve seat may have a higher pressure side and a lower pressure side, and the diameter of the valve seat may decrease from the higher pressure side to the lower pressure side for at least a portion of its length. In one embodiment, the valve seat is frustoconical in shape and has a constant angle of taper from its higher pressure side to its lower pressure side. When the valve is open, both sides of the valve seat may have a higher pressure at any given time.

[0013] When the valve body is in its closed position, the valve body may include an engaging portion having an annular sealing surface (optionally frustoconical in shape) that is complementary to the valve seat and configured to contact the valve seat in a sealing manner.

[0014] The elastomer seal may be installed on the engagement portion.

[0015] The valve body (for example, an elastomer seal) may include a cap portion and a tapered portion extending from the cap portion to the contact surface.

[0016] The retainer may form part of the piston connected to the cap portion. The piston may be connected to the cap portion at the end of the elastomer seal opposite the annular sealing surface.

[0017] The piston may extend laterally beyond the annular sealing surface of the engagement portion.

[0018] The lip may have a radially inward projection extending toward the central bore for at least 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, or 25% of the distance from the outer surface of the piston toward the center of the elastomer seal (e.g., the centerline of the central bore). In some embodiments, the projection may extend for 5% to 30% of the distance from the outer surface of the piston toward the central bore.

[0019] The engaging portion may define a seal support surface on which the internal contact surface of the elastomer seal is mounted. The seal support surface may have a frustoconical shape that widens as it extends toward the annular seal (optionally, the internal contact surface of the elastomer seal is frustoconical and positioned on the opposite side).

[0020] The retainer recess, the engagement portion seal support surface, and the internal contact surface of the elastomer seal may be combined in such a way that they resist deformation of the elastomer seal when the valve body moves from the closed position to the open position.

[0021] The contact surface of the elastomer seal optionally protrudes laterally beyond the annular sealing surface of the engaging portion. This arrangement allows the contact surface of the elastomer seal to contact the valve seat before the valve body reaches its fully closed position where the annular sealing surface contacts the valve seat. Further displacement of the valve body toward the fully closed position results in deformation of the elastomer seal and subsequent contact of the annular sealing surface with the valve seat. Thus, even if solid particles are trapped between the annular sealing surface and the valve seat, thereby preventing the valve body from displacing to its fully closed position, the provision of the elastomer seal (protruding laterally beyond the annular sealing surface) will obstruct the flow of the medium through the valve.

[0022] The end of the cap portion can be optionally extended beyond the contact surface of the elastomer seal.

[0023] The retainer may have any other convenient shape or configuration. For example, it may include an elongated device screwed or otherwise secured within an elastomer seal.

[0024] According to a second aspect of the present invention, a closing device for sealing a valve seat is provided, the closing device comprising: (i) an engaging portion defining (a) a sealing surface that is complementary to the valve seat when the closing device is in a closed position and configured to abut against the valve seat to seal; and (b) a seal support surface; (ii) an elastomer seal mounted on the seal support surface and having a contact surface configured to abut against the valve seat adjacent to the engaging portion sealing surface to seal; and (iii) a piston connected to the engaging portion and having a retainer, wherein the elastomer seal is held by the engaging portion and the retainer to resist displacement of the elastomer seal when the closing device is displaced away from its closed position toward its open position.

[0025] The piston may facilitate the lateral displacement of the elastomer seal when the closing device is displaced from its open position to its closed position.

[0026] The engagement portion and the elastomeric seal may include a valve body.

[0027] The elastomeric seal may define an annular contact surface.

[0028] Optionally, the contact surface of the elastomeric seal projects laterally beyond the sealing surface of the engagement portion, such that when the valve body is displaced towards its closed position, the contact surface contacts the valve seat in front of the sealing surface.

[0029] Optionally, the sealing surface comprises an annular sealing surface.

[0030] Optionally, the annular sealing surface has a frustoconical shape complementary to the frustoconical shape of the valve seat.

[0031] The piston may define a body portion and an outer side wall projecting beyond the body portion, and the retainer may extend laterally inwards from the outer side wall towards the engagement portion and may define a recess between the inner surface of the retainer and the body portion.

[0032] The elastomeric seal may define an annular tongue (or projection) extending laterally (or radially) beyond the side portion of the elastomeric seal. The side portion of the elastomeric seal may extend to the contact surface from under the annular projection.

[0033] According to a third aspect of the present invention, there is provided an elastomeric seal for use in a valve, the elastomeric seal comprising: an annular body having a valve seat end, an operating end, and a central hole extending through the body between the ends; an annular contact surface at the valve seat end configured to abut the valve seat for sealing; and a retaining formation defined at or towards the operating end of the body for engagement with a retainer.

[0034] The retaining formation may comprise an annular projection (such as a tongue).

[0035] The elastomer seal may be formed as a single, non-degradable molded product of an elastomer material such as polyurethane rubber. Depending on the liquid and temperature used, any other suitable elastomer material may be used, such as styrene-butadiene rubber (SBR), polyurethane rubber (PUR), ethylene propylene diene monomer (EPDM) rubber, fluoroelastomer (FKM) rubber, nitrile butadiene rubber (NBR), or hydrogenated acrylonitrile butadiene rubber (HNBR).

[0036] The annular contact surface may be in the shape of a frustocone, and the diameter of the contact surface increases as it moves away from the valve seat end.

[0037] A fourth aspect of the present invention provides a PEC pumping system comprising at least one PEC and a medium valve arrangement at one end of the PEC and a drive fluid valve arrangement at the end of the PEC opposite to the medium valve arrangement, wherein at least one of the valve arrangements comprises at least one valve of the above-described type.

[0038] According to a fifth aspect of the present invention, an elastomer seal for use in a valve is provided, the elastomer seal comprising: an annular body having a valve seat end, an operating end, and a centrally located hole extending through the body between the ends; an annular contact surface at the valve seat end configured to abut against the valve seat to seal; and a retaining formation defined at or toward the operating end of the body to engage with a retainer.

[0039] One of the features of the above embodiments may be combined with other embodiments.

[0040] Herein, these and other embodiments of the present invention will be described with reference to the attached schematic drawings as examples. [Brief explanation of the drawing]

[0041] [Figure 1] Figure 1 shows an axial cross-sectional view of a portion of a valve according to one embodiment of the present invention. [Figure 2]Figure 2 shows a cross-sectional view of a part of the valve (elastomer seal) of Figure 1 according to another embodiment of the present invention. [Figure 3A] Figure 3A shows an enlarged portion of the valve in Figure 1. [Figure 3B] Figure 3B shows a more detailed view of Figure 3A. [Figure 3C] Figure 3C shows a more detailed view of Figure 3B, but a portion (the elastomer seal) has been removed for clarity. [Figure 4] Figures 4 to 8 show cross-sectional views of the valve in Figure 1, illustrating sequentially the displacement of the valve body from the partially open position shown in Figure 1 to the closed position shown in Figure 6. [Figure 5] Figures 4 to 8 show cross-sectional views of the valve in Figure 1, illustrating sequentially the displacement of the valve body from the partially open position shown in Figure 1 to the closed position shown in Figure 6. [Figure 6] Figures 4 to 8 show cross-sectional views of the valve in Figure 1, illustrating sequentially the displacement of the valve body from the partially open position shown in Figure 1 to the closed position shown in Figure 6. [Figure 7] Figures 4 to 8 show cross-sectional views of the valve in Figure 1, illustrating sequentially the displacement of the valve body from the partially open position shown in Figure 1 to the closed position shown in Figure 6. [Figure 8] Figures 4 to 8 show cross-sectional views of the valve in Figure 1, illustrating sequentially the displacement of the valve body from the partially open position shown in Figure 1 to the closed position shown in Figure 6. [Figure 9A] Figure 9A shows an enlarged cross-sectional view of a portion of the valve body of the valves shown in Figures 1 to 8, with the elastomer seal in the appropriate location. [Figure 9B] Figure 9B shows an enlarged cross-sectional view of a portion of the valve body of the valves shown in Figures 1 to 8, with the elastomer seal removed. [Figure 10] Figure 10 schematically illustrates the pressure difference across the elastomer seal when the valve body of the valve is in its closed position. [Modes for carrying out the invention]

[0042] Here, reference numeral 10 refers to a drawing showing a valve according to one embodiment of the present invention. The valve 10 includes a housing, a portion of which is shown in the drawing and generally indicated by reference numeral 20. A first fluid port 22 (in this embodiment, an inlet) and a second fluid port 24 (in this embodiment, an outlet) are each defined by the housing 20, and a flow path generally indicated by reference numeral 26 extends through the housing 20 and connects the fluid ports 22 and 24 in flow communication, as will be described in more detail below. However, in other embodiments, the first fluid port 22 may be used as an outlet, and the second fluid port 24 may be used as an inlet.

[0043] The valve 10 further includes a valve seat, generally indicated by reference numeral 28, which is positioned between two fluid ports 22, 24. In one embodiment, the valve seat 28 may be formed by a hardened surface within the housing. In another embodiment shown in the drawings, the valve seat 28 is formed by an insert mounted on the housing 20, which facilitates the replacement of the valve seat 28 when it wears out.

[0044] The housing sleeve 29 is provided above the valve seat 28 and includes an opening that defines the first fluid port 22. The housing sleeve 29 holds the valve seat 28 in place by biasing the valve seat 28 into the housing 20. The housing sleeve 29 is a replaceable wear part when it is worn down by solid particles in the medium conveyed through the valve 10.

[0045] The valve seat 28 is an annular valve seat and defines a portion of the flow path 26. The valve seat 28 has a frustoconical shape and, as is typical for valve seats, has a narrow end 30 and a wider end 32. In other embodiments, the valve seat 28 may have an unconventional shape.

[0046] The closing device 34 is provided to open away from the valve seat 28 and close relative to the valve seat 28, thereby opening and closing the flow path 26. The closing device 34 comprises an engaging portion 36, an elastomer seal 38 mounted on the engaging portion 36, and a piston 40 connected to both the engaging portion 36 and the elastomer seal 38. The combination of the engaging portion 36 and the elastomer seal 38 may be called the valve body 42.

[0047] The engaging portion 36 defines a frustoconical annular sealing (or sealing) surface 44 that is complementary to the valve seat 28 and is configured to contact the valve seat 28 in a sealing manner when the valve body 42 is in its closed position. The sealing surface 44 may have any convenient shape, but is preferably complementary to the shape of the valve seat 28. In this embodiment, the sealing surface 44 is frustoconical. In this embodiment, the engaging portion 36 has a metal (or alloy) composition, but in other embodiments it may have a different composition (e.g., including ceramic).

[0048] The engaging portion 36 also defines a seal support surface 46 to which the elastomer seal 38 is fitted (for example, by adhesive or as a press fit). The seal support surface 46 has a frustoconical shape that widens as it extends toward the annular seal surface 44 (opposite to the frustoconical shape of the seal surface 44). The narrow end of the seal support surface 46 merges with a circular flange 48, from which a cylindrical sleeve 50 extends axially. The engaging portion 36 also defines a central bore 52 that extends axially through it and leads to an enlarged cavity 53 (also defined by the engaging portion 36) having an opening at the opposite end of the piston 40.

[0049] The piston 40 is generally cylindrical and defines a narrow central bore 54 (with the same or very similar diameter as the central bore 52 of the engagement portion) and a wider central bore 56 that accommodates the cylindrical sleeve 50 of the engagement portion 36.

[0050] As best seen in Figure 2, the elastomer seal 38 includes an annular body 60 having a generally planar piston end 62 for connecting to the piston 40 and a valve seat end 64 for connecting to the valve seat 28. The body 60 defines a contoured central opening 66 that extends through it and defines (i) a cylindrical piston portion 68, dimensioned to fit around the cylindrical sleeve 50 and to provide a relatively small expansion gap 69 (best seen in Figure 9A) between them to allow deformation of the elastomer seal 38 into the expansion gap during operation, and (ii) a frustoconical valve seat portion 70 (below the cylindrical piston portion 68), dimensioned to fit around the seal support surface 46 of the engaging portion 36 and optionally fixed thereto by adhesive, having an internal frustoconical contact surface 72. The annular body 60 also includes an external frustoconical contact surface 74 (which is tapered in the opposite direction to the internal frustoconical contact surface 72) and is sized to abut against the valve seat 28 in a sealing manner when the valve body 42 is in the closed position.

[0051] The generally planar annular flange engagement surface 76 extends between the cylindrical piston portion 68 and the frustoconical valve seat portion 70. The flange engagement surface 76 is positioned on the circular flange 48 of the engagement portion 36.

[0052] The annular body 60 further includes a tapered side wall 80 extending from the upper part of the outer frustoconical contact surface 74 to the lower side of the cap portion 82 at the piston end 62, such that the cap portion 82 forms a projection 84 that extends laterally beyond the tapered side wall 80. In this embodiment, the cap portion 82 is generally disc-shaped.

[0053] The distance from the periphery of the contoured central opening 66 to the outer edge of the cap portion 82 is labeled Dc in Figures 2 and 9A. As is best seen in Figures 3A–3C (which are enlarged views of parts of Figure 1) and 9B, the piston 40 further comprises a body 90 having an outer surface 92 and a generally planar elastomer engagement surface 94 on the lower part of the body 90, and extending substantially over the entire diameter of the body 90. The lower part of the outer surface 92 extends axially beyond the engagement surface 94 to form a collar 95, which then projects radially inward toward the central bore 54 to form a lip 96, which terminates to form an annular portion 98.

[0054] The recess 99 is defined between the engagement surface 94, the collar 95, and the inwardly projecting lip 96.

[0055] In this embodiment, the lip 96 extends by approximately 10% of the radius of the cylindrical body 90. In other embodiments, the lip 96 may extend by 5% to 30% of the distance from the outer surface 92 to the central bore 54. The lip 96 grips the cap portion 82 and thereby acts as a retainer to hold the elastomer seal 38 in place.

[0056] In this embodiment, the inwardly projecting lip 96 is generally parallel to the engagement surface 94 and transverse (or perpendicular in some embodiments) to the longitudinal axis 100 of the central bore 54.

[0057] In this embodiment, the recess 99 is generally C-shaped and has an opening that faces (i.e., opens toward) the longitudinal axis 100, and the collar 95 surrounds the cap portion projection 84 in the circumferential direction.

[0058] As best seen in Figure 9B (where the elastomer seal 38 is not shown), the circular flange 48 and the lip annular portion 98 are separated by a distance Dg less than the distance Dc. The combination of the circular flange 48 and the lip 96 provides support to the elastomer seal 38, preventing or reducing its extrusion during valve opening and thereby preventing (or at least significantly reducing) the elastomer seal 38 from being pulled out from the lip 96 when the valve is opened.

[0059] In some embodiments, Dg is less than 90% of Dc, in other embodiments, Dg is less than 85% of Dc, and in other embodiments, Dg is less than 80% of Dc.

[0060] The radius of the cap projection 84 and the height of the cap portion 82 are selected to be slightly smaller than the length and height of the recess 99 (best seen in Figure 9A), so preferably the cap portion 82 fits easily into the recess 99 when positioned within it, and also defines a lip expansion cavity 102 (best seen in Figure 9A) between the cap portion 82 and the collar 95. This allows the cap portion 82 to deform into the recess 99. Fluid communication channels (not shown) may be provided within the piston 40 (e.g., as an external groove and as an internal opening) to allow fluid to fill any space between the cap portion 82 and the recess 99, and to allow fluid to pass from the lip expansion cavity 102 or expansion gap 69 to the external groove.

[0061] The closing device 34 is assembled as follows: The cap portion 82 of the elastomer seal 38 is inserted into the recess 99 of the piston 40 until it is firmly gripped in place (this may involve temporary deformation of the cap portion 82). The engaging portion 36 is then inserted into the combination of the elastomer seal 38 and the piston 40. This brings the seal support surface 46 into contact with the internal frustoconical contact surface 72, and the planar elastomer engaging surface 94 into full contact with the upper surface of the cap portion 82. The circular flange 48 is also typically brought into contact with the flange engaging surface 76. The threaded rod (or stud bolt) 110 is positioned through the aligned bore 52 of the engaging portion 36 and the aligned bore 54 of the piston 40, and is secured in place by one or more nuts (or other fastening elements) 112 mounted on the end portion of the threaded rod 110 in the enlarged cavity 53, thereby biasing the combination of the engaging portion 36 and the elastomer seal 38 and the piston 40 toward each other, thereby sandwiching the elastomer seal 38 between the engaging portion 36 and the piston 40.

[0062] The outer frustoconical contact surface 74 of the elastomer seal 38 is sized to protrude beyond a line extrapolated from the sealing surface 44 (best seen in Figure 9), so that when the valve body 42 is displaced toward its closed position, the outer frustoconical contact surface 74 contacts the surface of the valve seat 28 before the sealing surface 44 of the engaging portion 36 contacts the valve seat 28.

[0063] The closing device 32 is movable along the central bore axis 100 to move the valve body 42 between the fully open position (see Figure 1) and the fully closed position (see Figure 8), and is precisely fitted with the low-friction housing sleeve 29. The movement of the closing device 32 is carried out by the linear displacement of a threaded rod 110, which is typically connected to a linear hydraulic actuator (not shown), although other displacement mechanisms are also possible.

[0064] As can be best seen in Figure 10 of the drawings, when the valve body 42 is in its closed position, the closing force indicated by arrow 122, i.e., the pressure applied to the valve body 42 by the medium (such as slurry), is substantially higher than the pressure applied to the other side (i.e., the opening force) applied to the valve body 42 by the medium on the side of the valve body, generally indicated by reference numeral 124, thanks to the pressure difference across the valve body 42.

[0065] An opening load is applied by the actuator to the threaded rod 110 in the direction of arrow 126 to displace the closing device 32 (and therefore the valve body 42, which is a part thereof) from its closed position to its open position. However, due to the pressure difference across the valve body 42, the outer frustoconical contact surface 74 of the elastomer seal 38 typically remains in contact with the valve seat 28, and the annular body 60 of the elastomer seal extends as the valve body 42 moves to the open position (upward in this embodiment). Thus, in practice, the elastomer seal 38 "sticks" to the valve seat 28. In extreme cases, deformation of the elastomer seal 38 could lead to damage to it, or partial or complete detachment of the elastomer seal from the engaging portion 36.

[0066] However, in this embodiment of the present invention, the piston 40 provides support to a portion of the elastomer seal 38 (the cap portion projection 84) at the end of the elastomer seal 38 opposite to the outer frustoconical contact surface 74, preventing, or at least significantly reducing, the outer frustoconical contact surface 74 from sticking to the valve seat 28. In addition, the circular flange 48 provides further support to another portion of the elastomer seal 38 (the flange engagement surface 76), further reducing the possibility of such sticking and the cap portion projection 84 “disengaging” from the recess 99.

[0067] The support function of this elastomer is provided by a lip 96 that projects radially inward toward the central bore 54. The lip 96 engages with a projection 84 of the cap portion 82, thereby assisting in lifting the entire annular body 60 of the elastomer seal 38 by applying an upward force (in this embodiment) in the direction of arrow 126 to the underside of the cap portion 82 (thanks to the lifting piston 40), thereby minimizing or preventing sticking. This upward force on the underside of the projection 84 resists deformation of the elastomer seal 38 in the opposite direction.

[0068] In addition, the projection 84 is sandwiched between the elastomer engagement surface 94 and the lip 96, which serves to hold the projection 84 in place until it reaches the outer radial edge of the recess 99 (or fills the lip expansion cavity 102) and to allow for any radial outward deformation thereof.

[0069] Furthermore, the complementary frustoconical surface 72 on the elastomer seal 38 and the complementary frustoconical surface 46 on the engaging portion 36 further function to resist displacement of the elastomer seal 38 in the direction opposite to that of arrow 126. Naturally, thanks to the complementary internal frustoconical contact surface 72 of the elastomer seal 38 and the seal support surface 46 of the engaging portion 36, any displacement of the elastomer seal 38 relative to the engaging portion 36 in the direction opposite to that of arrow 126 tends to expand the elastomer seal 38 radially, which biases the lip 96 more firmly into the recess 99 to hold the elastomer seal 38 in place.

[0070] As a result, when the valve body 42 is initially displaced away from its closed position during use, thanks to the natural elasticity of the elastomer seal 38 material, the outer frustoconical contact surface 74 of the elastomer seal 38 remains in contact with the valve seat 28 for a while, even after the annular sealing surface 44 (of the engaging portion 36) is no longer in contact with the valve seat 28. However, further displacement of the valve body 42 away from its closed position causes the elastomer seal 38 to displace to its open position along with the rest of the valve body 42, in a state where the lip 96 functions to hold the elastomer seal 38 in place and resist deformation that could lead to damage to the elastomer seal 38.

[0071] The valve 10 described above can be used in any convenient application, for example, in a positive displacement pump. The valve 10 may be used as an inlet valve or an outlet valve in any convenient orientation.

[0072] Naturally, the PEC pumping system can be constructed with a number of valves 10. The components of the PEC pumping system can be transported in a prefabricated or kit form for on-site assembly. Alternatively, an existing PEC pumping system can be modified by replacing one or more of the valves with valves 10 according to one embodiment of the present invention. [Explanation of symbols]

[0073] List of reference symbols Valve 10 Housing 20 First fluid port (inlet) 22 Second fluid port (outlet) 24 Flow path 26 Valve seat 28 Housing sleeve 29 Narrow end of valve seat 30 Wider end of valve seat 32 Closure device 34 Engagement part 36 Elastomer Seal 38 Piston 40 Valve body 42 44 Annular seal (or sealing) surface (engaging portion) 46 seal support surface (engaging portion) Circular flange (engaging portion) 48 Cylindrical sleeve (engaging portion) 50 Central hole (engaging portion) 52 Enlarged cavity (engaging portion) 53 Narrow central hole (of the piston) 54 Wider central hole (of the piston) 56 Ring-shaped body 60 Piston end 62 Valve seat end 64 Contoured central opening 66 Cylindrical piston portion 68 Extension interval 69 Truncated cone valve seat portion 70 Internal frustoconical contact surface 72 External frustoconical contact surface 74 Flange engagement surface 76 Tapered side wall 80 Cap portion 82 Projection 84 Cylindrical body 90 outer surface 92 Elastomer engagement surface (of piston) 94 Color 95 Lip 96 Ring section 98 Recess 99 Center bore shaft 100 Lip expansion cavity 102 Threaded rod 110 Fixing nut 112 Closing force 122 Opening force 124 Open load 126

Claims

1. It is an operating valve, Housing and An entrance leading into the aforementioned housing, An outlet connected to the housing at a position separated from the aforementioned inlet, A flow path connecting the aforementioned inlet and outlet in a state of continuous flow, A valve seat located within the aforementioned flow path and having a frustoconical shape, A valve body that is displaceable between a closed position that obstructs the flow of a medium through the channel and an open position that allows the flow of a medium through the channel, An engaging portion having a frustoconical annular sealing surface that is complementary to the valve seat and configured to contact the valve seat to seal when the valve body is in its closed position, and a sealing support surface that is frustoconical in shape and widens as it extends toward the annular sealing surface, A valve body comprising an elastomer seal mounted on the seal support surface, and having (i) a contact surface that protrudes laterally beyond the annular seal surface of the engaging portion, is complementary to the valve seat and abuts against the valve seat when the valve body is in its closed position, and therefore contacts the valve seat in front of the annular seal surface when the valve body is displaced toward its closed position, and (ii) a cap portion having a radius and height and forming a projection that extends radially outward in the upper portion of the projection, A retainer comprising an inwardly projecting lip defining a recess having length and height, wherein the radius and height of the cap portion are slightly smaller than the length and height of the recess to accommodate the projection within the cap portion in order to help lift the elastomer seal, and the lip expansion cavity is defined to allow some radially outward deformation of the cap portion into the recess, A valve comprising a retainer, which thereby minimizes or prevents the sticking or deformation of the elastomer seal when the valve body is displaced toward the open position away from its closed position.

2. The valve according to claim 1, wherein the elastomer seal includes a tapered side wall extending from below the cap portion to the contact surface, and the tapered side wall is tapered radially inward from the contact surface to below the cap portion.

3. The valve according to claim 2, further comprising a piston connected to the valve body and defining the retainer.

4. The valve according to claim 3, wherein the piston is connected to the cap portion.

5. The valve according to claim 3 or 4, wherein the lip extends for at least 5% of the distance from the outer surface of the piston toward its center.

6. The valve according to claim 1, wherein the internal contact surface of the elastomer seal defines a seal support surface on which the seal support surface is mounted.

7. The valve according to claim 2, wherein the end of the cap portion protrudes beyond the contact surface of the elastomer seal.

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