Valve with a valve insert containing two cylinders

Abstract

The present invention relates to a valve (10) for regulating flow between first and second ports (16, 18). A valve housing (12) includes a valve chamber (14) connected to the first and second ports (16, 18). A valve insert (26) inserted into the valve chamber (14) includes a first cylinder (28) connected to a second cylinder (32) and a piston (34) movably disposed within the second cylinder (32). The piston (35) acts against a valve seat gasket (30). The first and second cylinders (28, 32) are axially aligned and connected by a releasable connection (44). The valve seat gasket (30) is disposed within a valve seat gasket chamber (62) formed between the first and second cylinders (28, 32) and providing a ring-shaped opening (80) for engagement between the valve seat gasket (30) and the piston (34).

Description

[Technical Field]

[0001] The present invention relates to valves, and more particularly to valves for regulating flow between a first port and a second port. [Background technology]

[0002] Many types and designs of valves are known for various fields of use, particularly in the field of industrial refrigeration, where regulating valves for high operating pressures of 50 bar and above are used.

[0003] The applicant offers a product line of pressure and temperature control valves for industrial refrigeration equipment, particularly ICM-type motor-operated valves, which include a steel valve body, top cover, and functional module. Valve bodies of different sizes and connection types are available, and each body can be fitted with multiple top covers and different functional models to achieve diverse capabilities. The PTFE valve seat provides excellent valve airtightness. When combined with an actuator, a compact assembly is formed. The driving force from the actuator is transmitted via a magnetic coupling through a stainless steel top housing. The rotational motion of the magnetic coupling is transmitted to a spindle, which then moves the piston and valve seat up and down to open and close the valve. Valve inlet pressure acting on the underside of the PTFE valve seat is transmitted through the hollow piston assembly to the top of the piston, where it balances the pressure acting on the piston.

[0004] French Patent No. 2970055 (A1) discloses a valve with an annular abutment seal housed between a cage and a seat carrier.

[0005] U.S. Patent Application Publication No. 2021 / 222785 A1 describes a flow control device including a valve defining an inlet path, an outlet path, and a flow path. The valve seat assembly includes a fitting coupled to the valve body, a seat ring coupled to the fitting and defining a valve seat. The control element is movable relative to the valve body between a closed position in which the control element engages the valve seat and an open position in which the control element is spaced apart from the valve seat.

[0006] U.S. Patent No. 4,834,338(A) discloses a high-pressure fluid valve in which a valve plug moves relative to a cage against a valve seat having a deformable seal disposed in a cavity between a metal seal retainer and a seal ring housing.

[0007] U.S. Pat. No. 3,572,382(A) shows a single-port, dual-seat valve mechanism including a valve plug adapted to engage a first valve seat that terminates fluid flow through a flow passage in a valve body means, and a second valve seat means that cooperates with the valve plug to seal only when the valve plug is in a closed position relative to the first valve seat means.

[0008] U.S. Patent No. 3,272,219(A) discloses a two-way check valve having a body and cartridge formed from two coaxial, threaded main, inner, and outer portions, the inner portion being an open-ended sleeve and the outer portion being a cap that fits over the sleeve. Between the limits imposed by the cap and plug, a central opening in the sleeve provides a cylindrical valve chamber into which a reciprocable shuttle slides.

[0009] WO 2019 / 085141 A1 discloses a valve having a body, a cartridge mounted in the body, and a seat and a cage mating with the cartridge. A sealing ring is provided in an annular gap attached to the outer periphery of the cartridge.

[0010] Chinese Patent No. 113757399 discloses a sealing structure for a valve, which includes a first valve seat and a cage sleeve. The first valve seat is fixed to the valve body, and the second valve seat is connected to the first valve seat by a sleeve. The end face of the first valve seat facing the second valve seat has a V-shaped annular groove with an opening facing the second valve seat. The valve element / core is movable within the cage sleeve. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] French Patent Invention No. 2970055(A1) [Patent Document 2] US Patent Application Publication No. 2021 / 222785(A1) [Patent Document 3] U.S. Patent No. 4,834,338(A) [Patent Document 4] U.S. Patent No. 3,572,382(A) [Patent Document 5] U.S. Patent No. 3,272,219(A) [Patent Document 6] International Publication No. 2019 / 085141(A1) [Patent Document 7] Chinese Patent No. 113757399 Summary of the Invention [Problem to be solved by the invention]

[0012] Particularly at high pressures, sealing at the actual valve seat is particularly important. It may be considered an object to provide a valve of simple construction that allows a reliable attachment of the valve seat gasket. [Means for solving the problem]

[0013] This object is solved by a valve according to claim 1. The dependent claims refer to preferred embodiments.

[0014] The valve according to the present invention is suitable for regulating the flow of a fluid between a first port and a second port. The fluid may be, for example, a liquid, a gas, or a mixture thereof. The regulating function of the valve preferably includes a closed state in which the first and second ports are sealed from each other, and a variable valve open state for regulating the amount of fluid passing between the ports in response to a pressure differential.

[0015] The valve includes at least a valve housing having a valve chamber and a valve insert inserted into the valve chamber.

[0016] The valve housing can be shaped differently, depending for example on the angular arrangement of the first and second ports relative to each other and the valve chamber; the ports may be arranged at an angle relative to each other, although it is preferred that the ports are arranged in a straight line with the valve chamber interposed therebetween.

[0017] The valve insert comprises at least two cylinders, referred to herein as first and second cylinders, connected to one another and arranged, for example, axially aligned along a common central longitudinal axis, preferably arranged one on top of the other, with the top portion of the first cylinder being connected to the end portion of the second cylinder being particularly preferred. The cylinders preferably have an at least substantially hollow cylindrical shape, particularly preferably with circular outer and inner cross sections. The inner and / or outer diameter of the cylinder elements gradually changes along their axial length, forming a cone (e.g., having an inclined and / or curved shape in the axial longitudinal cross section), preferably a ring shape of different diameters (having steps in the axial longitudinal cross section). The term "at least substantially hollow cylindrical shape" may be understood to indicate that the cylinder elements may have additional elements, such as radial protrusions and / or radial openings, for example forming one or more radial windows.

[0018] The valve insert preferably further includes a movable piston that is axially movable. The first and / or second cylinder may define or provide a valve seat including a valve seat gasket. The piston is arranged for movement within the second cylinder and acts against the valve seat gasket to open and close the valve.

[0019] According to the present invention, the first and second cylinders are connected by a releasable connection, which is a threaded connection formed between a male thread and a female thread. The female thread can be located on the first cylinder and the male thread can be located on the second cylinder, or vice versa. As opposed to the cylinders being formed as a common, integral body or permanently connected, for example, by welding or gluing, the releasable connection of the first and second cylinders has the advantage that the valve seat gasket can be easily positioned and replaced if necessary.

[0020] The valve seat includes a valve seat gasket disposed in a valve seat gasket chamber formed between the first cylinder and the second cylinder and including at least one ring-shaped opening disposed and positioned to allow engagement between the piston and a valve seat gasket disposed in the valve seat gasket chamber.

[0021] Thus, when viewed in axial longitudinal section, the valve seat gasket chamber only partially surrounds the valve seat gasket, leaving at least one ring-shaped opening free. Preferably, the inner surface of the valve seat gasket chamber, formed by a portion thereof between the first and second cylinders, surrounds the valve seat gasket from at least two opposing sides, preferably from sides spaced apart axially or radially, thereby positioning and / or fixing the valve seat gasket. It is even more preferred that the inner surface surrounds the valve seat gasket from at least three sides, most preferably from four sides, and particularly preferably from two pairs of opposing sides, such as radial and axial, thereby accurately fixing the valve seat gasket in place.

[0022] Preferably, the first and second cylinders are made of a hard, durable material, preferably metal, and particularly preferably steel, while the valve seat gasket may be made entirely or partially of a softer material than the first and second cylinders, particularly a flexible material, such as elastomer, PTFE, or other gasket material. Thus, the valve seat gasket chamber, which partially encloses and surrounds the valve seat gasket, provides accurate positioning, mechanical support, and protection against the mechanical effects of fluid passing through the open valve, while the ring-shaped opening allows engagement between the piston and the valve seat gasket for sealing the valve in the closed position. Therefore, the ring-shaped opening is preferably provided to connect the valve seat gasket chamber to the internal space of the first and / or second cylinders.

[0023] A releasable, particularly threaded, connection serves to provide a well-defined, rigid and mechanically stable method for securing the first and second cylinders together.

[0024] According to a preferred embodiment, the first and / or second cylinder may include a step forming two inner surfaces, i.e., side walls, of the valve seat gasket chamber, where step is understood to mean an abrupt change in the inner or outer diameter of the respective cylinder such that, in an axial longitudinal section, two surfaces appear obliquely, preferably at right angles to each other.

[0025] In one preferred embodiment, the top portion of the first cylinder can be received within the end portion of the second cylinder, i.e., the outer diameter of the top portion of the first cylinder is less than the inner diameter of the end portion of the second cylinder. The "top portion" of the first cylinder and the "end portion" of the second cylinder refer to the axial ends of each cylinder oriented toward the other cylinder. The first cylinder may include a step that forms an outer ring space, and the second cylinder may include a step that forms an inner ring space. A valve seat gasket chamber can be formed between these steps, i.e., within both the inner ring space and the outer ring space. It should be understood that this structure can be reversed, i.e., the outer diameter of the end portion of the second cylinder can alternatively be smaller than the top portion of the first cylinder and received within it.

[0026] According to a further preferred embodiment, the valve seat gasket chamber can be formed between two pairs of radial and axial ring surfaces. Specifically, the top portion of the first cylinder can include a first axially opposed ring surface and a first radially opposed ring surface facing outward. The end portion of the second cylinder can include a second axially opposed ring surface and a second radially opposed ring surface facing inward. The first and second axially opposed ring surfaces are spaced apart from each other, and the first and second radially opposed ring surfaces are also spaced apart from each other, forming a valve seat gasket chamber therebetween.

[0027] To form the ring opening, one of the first and second axially opposed ring surfaces can be shorter than the other, and / or one of the first and second radial ring surfaces can be shorter than the other. This refers to the apparent length in an axial longitudinal cross section, and it should be understood that the length of each surface is measured in its direction of extension, i.e., radially or axially. Preferably, the longer axial surface and the radial surface together form one corner (in the axial longitudinal cross section) of the valve seat gasket chamber, so that the ring opening is formed in the opposite corner between the ends of the shorter axial surface and the shorter radial surface.

[0028] The piston, which is movably arranged relative to the valve seat gasket, is preferably at least substantially cylindrical. Its front face, which is oriented, for example, towards the first cylinder and / or towards the valve seat gasket, may be flat but preferably has at least one raised portion projecting in the axial direction. In a preferred embodiment, the cylinder may include an axially projecting central portion forming a tip, which, in an axial longitudinal cross section, preferably has a smooth arc-shaped connection with the remainder of the front face.

[0029] According to a further preferred embodiment, the piston may include an axially protruding outer ring that may be positioned to engage a valve seal gasket and seal the valve in the closed position, the raised feature providing a defined sealing position and seal.

[0030] Preferably, one of the ports (herein sometimes referred to as the first port, preferably the inlet) has a direct fluid connection with the interior space of the first cylinder and / or the second cylinder, while the other, second port (preferably the outlet) is connected to the interior of the first cylinder and / or the second cylinder only via the valve seat, so that the connection can be sealed when the piston engages the valve seat gasket. More preferably, the first cylinder can be sealingly received within the valve housing such that an axial opening of the first cylinder is connected to the first port. The second port may be connected to the interior of the first cylinder and / or the second cylinder by one or more radial openings provided in the first cylinder and / or the second cylinder. Preferably, at least one radial opening (sometimes referred to as a window) is provided in the second cylinder. A plurality of windows may be distributed around the circumference of the second cylinder.

[0031] According to a preferred embodiment, the second cylinder may include an outer valve seat ring portion axially disposed between the radial opening and the valve seat gasket. In the valve closed position, the front of the piston penetrates and is received within, i.e., surrounded by, the outer valve seat ring portion, while in the valve open position, the piston is axially spaced from the outer valve seat ring portion, thus providing an opening between the piston and the outer valve seat ring portion. The outer diameter of the piston and the inner diameter of the outer valve seat ring portion are preferably closely matched so that the two components are in sliding contact or have minimal radial clearance, such that in the valve closed position, the two components leave no or only minimal opening between them, thereby effectively closing the valve seat, which is sealed by the engagement of the piston and the valve seat gasket. Preferably, the outer valve seat ring portion provides a portion of the enclosure for the valve seat gasket chamber. More preferably, the annular opening of the valve seat gasket chamber is formed directly adjacent to the outer valve seat ring portion.

[0032] In a particularly preferred embodiment, the axially extending opening area of ​​the second cylinder can be defined by the position and axial extension of the window, i.e., the radial opening. The axially extending opening area can be defined as the axial height of the window. The valve chamber surrounding the first and / or second cylinder preferably includes an enlarged ring-shaped space portion, i.e., a portion with an enlarged inner diameter. According to a preferred embodiment, the enlarged ring-shaped space portion is at least partially axially arranged to overlap with the axially extending opening area. This increases the space for the medium to flow through the window, thereby enabling higher flow performance. More preferably, the axially extending opening area of ​​the second cylinder completely overlaps with the enlarged ring-shaped space portion surrounding the second cylinder. Particularly preferably, the axially extending opening area of ​​the second cylinder is located at the center of the enlarged ring-shaped space portion surrounding the second cylinder.

[0033] The piston may be solid, but is preferably provided with a pressure equalization chamber and a fluid-conducting passageway that traverses the piston and is connected to it. The pressure equalization chamber may be formed behind the piston (optionally partially within the piston) so that at least a front portion of the piston, particularly preferably the entire piston, is axially positioned between the valve seat and the pressure equalization chamber. The fluid-conducting passageway that traverses the piston includes an inlet formed in the front surface of the piston, i.e., the surface facing toward the first cylinder and / or the valve seat gasket. Preferably, the inlet is located on the radially outer portion of the piston, preferably at a distance (measured at the center of the inlet) of more than 50% of the radius from the center of the piston, more preferably more than 75% of the radius, particularly preferably more than 80% of the radius.

[0034] As mentioned above, the second cylinder preferably includes one or more radial openings (windows). Preferably, the position of the inlet of the fluid-conducting passage formed in the front face of the piston is aligned with the position of one of the windows. The windows can be arranged over an angular range around the circumference of the second cylinder, and the inlet can preferably be arranged within the angular range. The range of the angular range can be determined in a cross section perpendicular to the longitudinal axis of the first / second cylinder, and the position of the inlet can be determined by its center.

[0035] In a preferred embodiment, the piston may include at least first and second guide ring surfaces on its circumference. The diameter of the piston at the first and second guide ring surfaces may be larger than the diameter of the piston between the first and second guide ring surfaces. The first and second guide ring surfaces may be arranged to contact the second cylinder and may be axially spaced apart from each other, for example, by more than 50% of the axial length of the piston. This arrangement provides good guidance for the piston's axial movement within the second cylinder, guided by the guide ring surfaces sliding against the inner surface of the second cylinder.

[0036] Hereinafter, embodiments of the present invention will be described with reference to the drawings. [Brief explanation of the drawings]

[0037] [Figure 1] 1 shows a first embodiment of a valve in a perspective view; [Figure 2] The valve of Figure 1 is shown in an exploded view. [Figure 3] The axial longitudinal section of the valve of Figs. [Figure 4a-4b] 4 shows an axial longitudinal section of the inner part of the valve of FIGS. 1 to 3 in the closed position (4a) and in the open position (4b). [Figure 5] 3. The enlarged portion B of FIG. [Figure 6] A cross-sectional view along C...C in Figure 4a is shown. [Figure 7]4 shows a second preferred embodiment of the valve in an axial longitudinal section comparable to FIG. 3. DETAILED DESCRIPTION OF THE INVENTION

[0038] 1 shows a first embodiment of a valve 10 comprising a valve housing 12 including a valve chamber 14, a first port (inlet) 16, and a second port (outlet) 18. In the illustrated embodiment, the valve 10 is a regulating valve for industrial refrigeration and can be used with low and high pressure refrigerants having different refrigerant phases, including two phases of refrigerant, for example, a liquid refrigerant at the inlet and a two-phase refrigerant at the outlet.

[0039] Valve 10 includes a top portion 20 having a top cover 22 and a cup 24 containing a magnet to which an actuator can be magnetically coupled to control the valve opening, i.e., to regulate fluid flow between first port 16 and second port 18.

[0040] 2 shows an exploded view of valve 10. As shown therein, valve insert 26 is inserted into valve chamber 14. Valve insert 26 includes first cylinder 28, valve seat gasket 30, second cylinder 32, piston 34, and spindle 36 with spindle nut 38.

[0041] The top portion 20 and valve insert 26 together may be referred to as the functional module 21. Different types of functional modules 21 may be attached to the valve housing 12, for example, for different flow capabilities.

[0042] The first and second cylinders 28, 32 of the valve insert 26 are hollow cylinders with different inner and outer diameters, thus defining an interior space. The inner and outer diameters of the first cylinder decrease toward its top portion 40, thus forming a cone. The inner diameter of the second cylinder 32 is constant except for an enlarged end 42.

[0043] FIG. 3 shows the assembled valve 10 in an axial longitudinal cross section parallel to the longitudinal axis X.

[0044] As shown, the elements of the valve insert 26 are sealingly disposed within the valve chamber 14 such that the bottom opening of the first cylinder 28 is directly connected to the first port 16 and the radially outwardly of the first and second cylinders 28, 32 and surrounding the valve chamber 14 are directly connected to the second port 18.

[0045] The first and second cylinders 28, 32 are coaxially disposed one above the other, with a top portion 40 of the first cylinder 28 connected to an end portion 42 of the second cylinder 32 by a releasable connection, in the preferred example shown by a threaded connection 44 formed between an internal thread on the end portion 42 of the second cylinder 32 that engages with an external thread formed around the periphery of the top portion 40 of the first cylinder 28. A piston 34 is received within the second cylinder 32 and is axially movable relative thereto by rotation of a spindle 36 relative to a spindle nut 38.

[0046] The piston 34 has a radially projecting first guide ring 50 disposed toward its top and a radially projecting second guide ring portion 52 spaced axially therefrom. The outer surfaces of the guide ring portions 50, 52 contact the inner surface of the second cylinder 32 and serve to guide the piston 34 therein. Axial movement of the piston 34 is further guided, and rotational movement is prevented, by a guide screw 47 fixed to the second cylinder 32 and received in an axial guide groove 49 in the piston 34.

[0047] As can be seen in the longitudinal cross section of Figure 3, the piston 34 has a forward face 46 with a central axially protruding tip 48, and an outer raised ring portion 78 (visible in the enlarged view of Figure 5). As will be explained, the outer ring 78 serves to seal the valve 10 by engaging the valve seat gasket 30.

[0048] Located behind the piston 34 is a pressure equalization chamber 54 which, in the presently shown embodiment, comprises a cavity 55 disposed within the piston. The pressure equalization chamber 54 is connected to the front face 46 of the piston 34 by a passage 56 which leads to an inlet 58 disposed in the front face 46. The passage 56 and the pressure equalization chamber 54 serve to counterbalance the piston 34 against high pressure from the inlet side (first port 16).

[0049] The second cylinder 32 includes radial windows 60 that connect the interior spaces of the first cylinder 28 and the second cylinder 32 to the surrounding valve chamber 14. In different embodiments, the number of windows 60 may be different, such as only one, only two, or more. In this embodiment, as shown in FIG. 6, two windows 60 are disposed opposite each other, each covering an angular range α of approximately 45°.

[0050] The axial height of the window 60 is shown in FIG. 3 as defining an axially extending opening region 82. It should be noted that the valve chamber 14 includes sections of different diameters, narrower at the top section surrounding the top portion of the second cylinder 32 and larger at the annular space section 84 surrounding the valve seat. The inner diameter of the valve chamber 14 varies across two conical sections 86a, 86b. The enlarged annular space section 84 completely overlaps the axially extending opening region 82, as shown in FIG. 3.

[0051] The first and second cylinders 28, 32 define a valve seat gasket chamber 62 between the top portion 40 of the first cylinder 28 and the end portion 42 of the second cylinder 32. As can be seen particularly in the enlarged view of Figure 5, the valve seat gasket chamber 62 is defined between a first outer step 64 on the top portion 40 of the first cylinder 28 and a second inner step 66 on the end portion 42 of the second cylinder 32.

[0052] The first outer step 64 presents an outwardly facing first axial ring surface 68 and a first radial ring surface 70. The second inner step 62, located in the end portion 42 of the second cylinder 32, defines an inwardly facing second radial ring surface 72 and a second axial ring surface 74. Thus, the valve seat gasket chamber 62 and the valve seat gasket 30 contained therein are bounded on all sides by a pair of axially facing ring surfaces 68, 74 and a pair of radially facing ring surfaces 70, 72.

[0053] The first radial ring surface 70 is shorter than the second radial ring surface 72, and the second axial ring surface 74 is shorter than the first axial ring surface 68. The first axial ring surface 68 and the second radial ring surface 72 meet and form a corner portion of the valve seat gasket chamber 62. The opposite corner portion defines a ring opening 80 that exposes the valve seat gasket 30 to the interior spaces of the first and second cylinders 28, 32. As will become apparent, the ring opening 80 allows the piston 34 to engage the valve seat gasket 30 therethrough.

[0054] The second inner step 66 in the end portion 62 of the second cylinder 32 forms a portion of the second cylinder 32 referred to herein as the outer valve seat ring portion 76. The outer valve seat ring portion 76 abuts the valve seat gasket chamber 62. It extends radially inward and provides sliding contact (or minimum clearance) with the circumferential surface of the piston 34.

[0055] 5 and 6, inlet 58 of passage 56 traversing piston 34 to cavity 55, which is part of pressure equalization chamber 54, is located radially outward within front face 46 of piston 34. FIG. 6 shows that the distance R1 between central longitudinal axis X and the center of inlet 58 is close to radius R of piston 34.

[0056] Furthermore, FIG. 6 shows that the inlet 58 is positioned within one angular range α of the window 60 .

[0057] In operation of valve 10, an actuator (not shown) can be attached to magnetic cup 24 to impart rotation to spindle 36, which in turn actuates valve nut 38 to adjust the axial position of the piston in second cylinder 32, thereby closing valve 10 or providing a variable opening of valve 10. The modulation function of valve 10 will now be described with reference to Figures 4a and 4b.

[0058] Figure 4a shows the valve 10 in a closed position, and Figure 4b shows the valve 10 in an open position.

[0059] In the open position of the valve, shown in Figure 4b, the piston 34 is in a retracted, upward position within the second cylinder 32 such that the front face 46 of the piston 34, and in particular its raised outer ring 78 (see Figure 5), is spaced apart from the valve seat gasket 30 and outer valve seat ring portion 76. Thus, a valve opening is provided that allows fluid from the inlet side (first port 16) to pass through the valve seat, through the window 30, into the valve chamber 14, and out to the outlet side (second port 18).

[0060] It should be noted that only a small portion of the valve seat gasket 30 is exposed to fluid flow through the valve opening, i.e., only the portion of the valve seat gasket 30 exposed by the ring opening 80 is exposed to fluid flow through the valve opening.

[0061] It should further be noted that due to the location of the inlet 58 of the passage 56, the pressure within the pressure equalizing chamber 54 is equalized to the pressure at the valve seat, i.e., the pressure between the valve seat gasket 30 and the circumference of the front face 46 of the piston 34.

[0062] To close the valve 10, the piston 34 is moved axially until the front face 46 of the piston 34, and more particularly its raised outer ring 78, penetrates and is thereby received by the outer valve seat ring portion 76 and engages the flexible valve seat gasket 30, thereby closing and sealing the valve 10.

[0063] 7 shows a second preferred embodiment of a valve 110, which in many respects corresponds to the valve 10 according to the first embodiment. Parts common to both embodiments are designated by the same reference numerals. In the following, only the differences between the embodiments will be considered in detail.

[0064] Similar to the first embodiment valve 10, the valve 110 has a valve insert including coaxial first and second cylinders 128, 132 that are releasably connected to secure the valve seat gasket 30 within the valve seat gasket chamber 62 formed therebetween. A piston 34 actuated by a spindle 36 is movably disposed within the second cylinder 132.

[0065] The second embodiment valve 110 has a differently shaped valve chamber 112 compared to the first embodiment valve 10, with the inlet 16 and outlet 18 positioned at right angles to each other. Like the first embodiment valve chamber 12, the valve chamber 112 has an enlarged diameter ring-shaped space section 84 surrounding the valve seat. The axially extending opening area 82, defined by the axial height of the window 60, is centered within the ring-shaped space section 84, further promoting flow.

[0066] In the second embodiment valve 110, the axial movement of the piston 34 is fixed by the top cover 22 and guided by a guide pin 147 received in the axial guide groove 49 of the piston 34, and rotational movement is prevented.

Claims

1. A valve (10) for regulating flow between first and second ports (16, 18), comprising at least: a valve housing (12) including a valve chamber (14) connected to said first and second ports (16, 18); a valve insert (26) inserted into said valve chamber (14), said valve insert (26) comprising at least a first cylinder (28) connected to a second cylinder (32) and a piston (34) movably arranged in said second cylinder (32), said piston (35) acting against a valve seat gasket (30); Including, - said first cylinder (28) is formed as a cone with a circular cross section and gradually varying inner and outer diameters, said inner and outer diameters decreasing towards said second cylinder (32); - the first and second cylinders (28, 32) are arranged in axial alignment and are connected by a releasable threaded connection (44) by an internal thread on the first cylinder (28) engaging with an external thread on the second cylinder (32) or by an external thread on the first cylinder (28) engaging with an internal thread on the second cylinder (32); the valve seat gasket (30) is disposed within a valve seat gasket chamber (62), the valve seat gasket chamber (62) being formed between the first and second cylinders (28, 32), the valve seat gasket chamber (62) providing a ring-shaped opening (80) for engagement between the valve seat gasket (30) and the piston (34); Valve (10).

2. - said releasable threaded connection (44) comprises the external thread of said first cylinder (28) engaging with the internal thread of said second cylinder (32); The valve (10) of claim 1.

3. the top portion (40) of said first cylinder (28) is received within the end portion (42) of said second cylinder (32); - said first cylinder (28) comprises a step (64) forming an outer annular space; - said second cylinder (32) comprises a step (66) forming an inner annular space; - the valve seat gasket chamber (62) is formed between the stages (64, 66); A valve (10) according to claim 1 or 2.

4. the top portion (40) of said first cylinder (28) includes a first axially opposed ring surface (68) and a first radial ring surface (70), said first radial ring surface (70) facing outward; - said end portion (42) of said second cylinder (32) includes a second axially opposed ring surface (74) and a second radial ring surface (72), said second radial ring surface (72) facing inward; - said first and second axially opposed ring surfaces (68, 74) are arranged opposite each other at a distance, and said first and second radially opposed ring surfaces (70, 72) are arranged opposite each other at a distance, forming said valve seat gasket chamber (62); A valve (10) according to claim 3.

5. one of said first and second axially opposing ring surfaces (68, 74) is shorter than the other, measured radially in the axial longitudinal section, and / or one of said first and second radial ring surfaces (70, 72) is shorter than the other, measured axially in the axial longitudinal section, - thereby forming said ring-shaped opening (80), A valve (10) according to claim 4.

6. - the piston (34) includes an axially projecting outer ring (78) arranged to engage the valve seal gasket (30); A valve (10) according to claim 1 or 2.

7. - the first cylinder (28) is sealingly received within the valve housing (14), the first cylinder (28) including an interior space connected to the first port (16); - said second cylinder (32) comprises at least one radial opening (60) connected to said second port (16); A valve (10) according to claim 1 or 2.

8. - said second cylinder (32) comprises one or more radial openings (60); the second cylinder (32) includes an outer valve seat ring portion (76) axially disposed between at least one of the radial openings (30) and the valve seat gasket (30); in the closed position of the valve (10), a portion of the piston (34) is received within the outer valve seat ring portion (76); in the open position of the valve (10), the piston (34) is spaced axially from the outer valve seat ring portion (76), thus providing an opening between the piston (34) and the outer valve seat ring portion (76); A valve (10) according to claim 1 or 2.

9. - said outer valve seat ring portion (76) is part of the enclosure of said valve seat gasket chamber (62); the annular opening (80) of the valve seat gasket chamber (62) is formed directly adjacent to the outer valve seat ring portion (76); A valve (10) according to claim 8.

10. - the radial opening (60) of the second cylinder (32) extends over an axially extending opening area (82); the valve chamber (14) comprises an enlarged ring-shaped space portion (84) surrounding the first and / or second cylinder (28, 32), the enlarged ring-shaped space portion (84) being arranged so as to at least partially overlap the axially extending opening area (82); A valve (10) according to claim 7.

11. - said piston (34) comprises a front face (46); a fluid conducting passage (56) arranged at least partially across said piston (34), said fluid conducting passage (56) connecting a pressure equalization chamber (54) to an inlet (58) formed in said front face (46); - said inlets (58) are arranged in the radially outer part of said front face (46); A valve (10) according to claim 1 or 2.

12. - said piston (34) comprises a front face (46); the angular extent (α) of said second cylinder (32) is defined by the width of at least one of said radial openings (60) determined in a cross section perpendicular to the longitudinal axis of said second cylinder (32), the inlets (58) formed in said front face (46) are located within said angular range (α); A valve (10) according to claim 7.

13. - said piston (34) comprises, on its circumference, at least a first guide ring surface (50) in contact with said second cylinder (32) and a second guide ring portion (52) in contact with said second cylinder (32); - said first and second guide ring surfaces (50, 52) are axially spaced apart from one another; the diameter of the piston (34) at the first and second guide ring surfaces (50, 52) is greater than between the first and second guide ring surfaces (50, 52); A valve (10) according to claim 1 or 2.

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