A small-caliber top-mounted low-temperature fixed ball valve

Abstract

The present invention belongs to the technical field of ball valves, and relates to a small-diameter top-mounted low-temperature fixed ball valve. A small-diameter top-mounted low-temperature fixed ball valve comprises a valve body, a valve cover, an inlet and outlet valve seat assembly, a ball, and a valve stem. The valve cover is located above the valve body, the ball is located at the center of the valve body channel, the inlet and outlet valve seat assembly comprises a graphite rope and a soft valve seat, the valve seat assembly is connected to the valve body, the soft valve seat in the valve seat assembly is connected to the ball, and the valve stem passes through the valve cover and is connected to the ball. The significant effect of the present invention is that the ball is designed as a whole with the upper and lower cylindrical shafts, which solves the problem that the hole on the ball of a small-diameter fixed ball valve is inserted into the pivot for fixation, which affects the strength of the ball. The design of the upper and lower cylindrical shafts of the one-piece ball is conducive to ensuring the coaxiality on the vertical axis. The ball fixing effect is good under the action of the medium pressure, which can improve the sealing effect of the valve and reduce the valve torque.

Description

Technical Field

[0001] The invention belongs to the technical field of ball valves and relates to a small-caliber top-mounted low-temperature fixed ball valve. Background Art

[0002] A ball valve is a valve whose opening and closing element (the ball) rotates along the vertical axis of the valve body, driven by the valve stem, to achieve opening and closing. In a trunnion-mounted ball valve, the ball is secured by upper and lower bearings. The valve seat floats under the pressure of the medium, sealing the ball tightly against the ball. Ball valves are primarily categorized by mounting method as side-mounted or top-mounted. Top-mounted ball valves offer fewer external leaks and allow for online maintenance of internal seals. Top-mounted trunnion-mounted ball valves for cryogenic media are known as top-mounted, low-temperature trunnion-mounted ball valves.

[0003] At present, top-mounted low-temperature fixed ball valves are widely used in engineering. The existing small-diameter (valve channel less than 49mm) top-mounted fixed ball valves on the market have complex structures and are not easy to disassemble and assemble online. Therefore, a small-diameter top-mounted low-temperature fixed ball valve is needed. Summary of the Invention

[0004] Aiming at the defects of the prior art, the present invention provides a small-caliber top-mounted low-temperature fixed ball valve.

[0005] The present invention is achieved as follows: a small-diameter top-mounted low-temperature fixed ball valve includes a valve body, a valve cover, inlet and outlet valve seat assemblies, a ball, and a valve stem. The valve cover is located above the valve body, the ball is located in the center of the valve body channel, the inlet and outlet valve seat assemblies include graphite ropes and soft valve seats, the valve seat assembly is connected to the valve body, the soft valve seat in the valve seat assembly is connected to the ball, and the valve stem passes through the valve cover and is connected to the ball.

[0006] The disc spring is located between the valve body and the valve seat assembly; the valve body and the valve cover are detachably connected; the valve stem is connected to the ball, driving the ball to rotate around the vertical axis.

[0007] The outer wall of the inlet and outlet valve seat assembly is covered with a lip seal ring, which contacts the valve body. The cylindrical surface of the inlet and outlet valve seat assembly is processed with an annular groove, and a graphite rope is arranged in the groove.

[0008] The inlet and outlet valve seat components are machined with an arc groove along the end surface of the large cylinder around the horizontal axis.

[0009] The sphere is provided with two cylindrical shafts at upper and lower positions along the vertical axis. The lower cylindrical shaft of the sphere is inserted into the valve body, and the upper cylindrical shaft is inserted into the valve stem.

[0010] A bearing is arranged between the lower cylindrical shaft of the sphere and the valve body, and a thrust pad is arranged between the bottom surface of the inner cavity of the valve body and the lower boss of the sphere.

[0011] A bearing is arranged between the cylindrical shaft on the sphere and the valve cover, and a threaded hole is arranged on the top of the sphere.

[0012] A circle of protruding cylinders is processed on the bottom of the valve cover, and a thrust pad is provided between the frustum at the bottom of the valve stem and the valve cover.

[0013] A lip seal ring is provided between the valve stem and the valve cover, and the bearing is located at the lower part of the lip seal ring.

[0014] A packing is arranged between the valve stem and the valve cover, the upper part of the packing is compressed by a pressing sleeve 8, and a packing pad is arranged at the lower part of the packing.

[0015] The valve is equipped with an online disassembly and assembly tool, the bottom of the tool pin is conical, and four pins are fixed in the tool plate.

[0016] The significant benefit of this invention is that the ball and upper and lower cylindrical shafts are integrated, resolving the issue of small-diameter fixed ball valves requiring a pivot for insertion into the ball through a hole in the ball. The integrated upper and lower cylindrical shafts ensure vertical coaxiality, effectively securing the ball under medium pressure, improving valve sealing and reducing valve torque.

[0017] The valve is equipped with an online disassembly tooling that facilitates in-line maintenance of the valve body. The tooling pin is inserted into the inner cavity of the valve body. The outer diameter of the pin contacts a circular groove on the valve seat assembly, pushing the valve seat assembly toward the ends of the valve, freeing the soft valve seat from the spherical surface. This creates a gap between the valve seat assembly and the ball, facilitating ball removal and making online disassembly and assembly simple and convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a structural diagram of a small-diameter top-mounted low-temperature fixed ball valve.

[0019] Figure 2 Schematic diagram of the valve seat assembly.

[0020] Figure 3 Schematic diagram of the sphere structure.

[0021] Figure 4 This is a schematic diagram of online disassembly and assembly tooling.

[0022] Figure 5 This is a schematic diagram for online disassembly and assembly.

[0023] In the figure: 1 valve body; 2 valve cover; 3 nut; 4 stud; 5 insulation board; 6 bearing; 7 lip seal; 8 packing gland; 9 graphite packing; 10 packing pad; 11 valve stem; 12 thrust pad; 13 bearing; 14 seal pad; 15 lip seal; 16 fireproof pad; 17 disc spring; 18 valve seat assembly; 19 bearing; 20 thrust pad; 22 outer wall; 23 arc groove; 24 soft valve seat; 25 upper cylindrical shaft; 26 lower cylindrical shaft; 27 lower boss; 28 threaded hole; 29 grounding spring; 30 grounding steel ball; 31 latch; 32 tooling plate. DETAILED DESCRIPTION

[0024] The present invention will be further described with reference to the figures and embodiments.

[0025] like Figure 1 As shown, the fixed ball valve includes a valve body 1, an inlet valve seat assembly 18 is installed at the inlet of the valve body 1 channel, an outlet valve seat assembly 18 is installed at the outlet of the valve body 1 channel, and a ball 21 is installed between the two valve seat assemblies. The ball 21 is located at the center of the valve body channel.

[0026] The disc spring 17 is located between the valve body 1 and the valve seat assembly 18. The disc spring 17 provides a pre-tightening force to push the valve seat assembly 18 to press the ball 21 to form an initial seal.

[0027] A sealing gasket 14 is provided between the valve body 1 and the valve cover 2, and a detachable connection is formed by the stud 4 and the nut 3.

[0028] The valve stem 11 passes through the center hole of the valve cover 2 and is connected to the ball 21, driving the ball 21 to rotate around the vertical axis to complete the switching action.

[0029] like Figure 2 As shown, the lip seals 15 are inserted into the outer walls 22 of the inlet and outlet valve seat assemblies 18. The lip seals 15 contact the valve body 1, forming a seal between the valve body 1 and the valve seat assembly 18. The inlet and outlet valve seat assemblies 18 have an annular groove machined into the cylindrical surface. Graphite ropes 16 are installed in the grooves. Soft valve seats 24 are inserted into the barbed valve seat grooves.

[0030] like Figure 3 As shown, the sphere 21 is provided with two cylindrical shafts, one above and one below, along its vertical axis. The lower cylindrical shaft 26 of the sphere 21 is inserted into the valve body 1, while the upper cylindrical shaft 25 is flattened and inserted into the valve stem 11. A bearing is provided between the lower cylindrical shaft 26 and the valve body 1, and a thrust pad 20 is provided between the bottom surface of the inner cavity of the valve body 1 and the lower boss of the sphere 21. A bearing 19 is provided between the upper cylindrical shaft 25 of the sphere 21 and the valve cover 2. A threaded hole 28 is provided on the top of the sphere 21.

[0031] like Figure 1 As shown, a circle of protruding cylinders is processed on the bottom of the valve cover 2, and a thrust pad 12 is provided between the frustum at the bottom of the valve stem 11 and the valve cover 2.

[0032] like Figure 2 、 4 As shown in Figures 5 and 6, the inlet and outlet valve seat assemblies 18 are machined with an arc groove 23 along the end face of the large cylinder around the horizontal axis. Four pins 31 are fixed in the tooling plate 32. During online maintenance, the pins 31 are knocked into the valve cavity. The outer circle of the pins 31 contacts the arc groove 23 on the valve seat assembly 18, pushing the valve seat assembly 18 to move toward the two ends of the valve, so that the soft valve seat 24 is separated from the spherical surface, forming a gap between the valve seat assembly 18 and the ball 21, making it easier to remove the ball 21.

[0033] A lip seal 7 is installed between the valve stem 11 and the valve cover 2, and the bearing 6 is located below the lip seal 7. A packing 9 is installed between the valve stem 11 and the valve cover 2. The upper part of the packing 9 is compressed by a compression sleeve 8, and a packing pad 10 is installed below the packing 9. The lip seal 7 and the packing 9 form a double stem seal to prevent leakage at the valve stem 11.

Claims

1. A small-caliber top-mounted low-temperature fixed ball valve, comprising a valve body (1), a valve cover (2), an inlet and outlet valve seat assembly (18), a ball (21), and a valve stem (11), wherein the valve cover (2) is located above the valve body (1), the ball (21) is located at the center of the valve body (1) channel, the inlet and outlet valve seat assembly (18) comprises a graphite rope (16) and a soft valve seat (24), the valve seat assembly (18) and the valve body (1) are connected, the soft valve seat (24) in the valve seat assembly (18) is connected to the ball, and the valve stem (11) passes through the valve cover (2) and is connected to the ball (21); The disc spring (17) is located between the valve body (1) and the valve seat assembly (18); the valve body (1) and the valve cover (2) are detachably connected; the valve stem (11) is connected to the ball (21), driving the ball (21) to rotate around the vertical axis; A lip seal ring (15) is inserted into the outer wall (22) of the inlet and outlet valve seat assembly (18), and the lip seal ring (15) contacts the valve body; an annular groove is machined on the cylindrical surface of the inlet and outlet valve seat assembly (18), and a graphite rope (16) is arranged in the groove; The inlet and outlet valve seat components (18) are machined with a circular arc groove (23) along the end surface of the large cylinder around the horizontal axis; The sphere (21) is provided with two cylindrical shafts at upper and lower positions along the vertical axis. The lower cylindrical shaft (26) of the sphere (21) is inserted into the valve body (1), and the upper cylindrical shaft (25) is flattened and inserted into the valve stem (11). A bearing (19) is provided between the lower cylindrical shaft (26) of the sphere (21) and the valve body (1), and a thrust pad (20) is provided between the bottom surface of the inner cavity of the valve body and the lower boss (27) of the sphere; A bearing (13) is provided between the cylindrical shaft (25) on the sphere (21) and the valve cover (2), and a threaded hole (28) is provided on the top of the sphere (21); A circle of protruding cylinders is processed on the bottom of the valve cover (2), and a thrust pad (12) is provided between the frustum at the bottom of the valve stem (11) and the valve cover; A lip seal ring (7) is provided between the valve stem (11) and the valve cover (2), and the bearing (6) is located below the lip seal ring (7); A packing (9) is provided between the valve stem (11) and the valve cover (2), the upper portion of the packing (9) is compressed by a compression sleeve (8), and a packing pad (10) is provided at the lower portion of the packing (9); The valve is equipped with an online disassembly tool. The bottom of the tool pin (31) is conical. Four pins (31) are fixed in the tool plate (32).

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