Metal hard sealing ball valve

Abstract

The invention provides a metal hard sealing ball valve which is high in stability. The ball valve comprises a valve body and a valve rod, a ball core is installed in the valve body, a connecting section at the bottom of the valve rod is inserted into the top end of the ball core and is a threaded rod, a locking nut and a flat square shaft sleeve are installed on the threaded rod in a threaded mode, and the flat square shaft sleeve is fixedly connected with a flat square through a positioning screw. And a spring with a special structure is pressed between the upstream valve seat and the right valve body cap and is made of an elastic thin plate.

Description

Technical Field

[0001] The present invention relates to the technical field of valves, in particular to a metal hard-sealed ball valve. Background Art

[0002] Metal ball valves are a common industrial valve widely used in fluid control systems. Their principle is to rotate the valve stem to drive the valve core ball, aligning or perpendicular to the pipeline, thereby achieving fluid flow, shutoff, or regulation. Metal hard-seal ball valves are made of a special high-strength alloy steel material with excellent compressive strength and corrosion resistance. They also offer sensitive opening and closing, excellent sealing performance, and resistance to high temperatures, corrosion, and wear. Suitable for piping systems with high-temperature, high-pressure, and corrosive media, they have a long service life, effectively controlling the fluid's operating state and improving system efficiency. They are widely used in various fields, including petrochemicals, electric power, metallurgy, municipal water supply, and pharmaceuticals. In such demanding media environments, metal hard-seal ball valves require a ball valve structure that offers excellent sealing performance, low opening and closing torque, and convenient online seat replacement.

[0003] Existing metal ball valves such as Figure 1 、 Figure 8 As shown, a metal ball valve comprises a valve body 1 and a valve stem 2, wherein the valve stem 2 comprises a handle 201 at the top, a stem 202 in the middle and a connecting section 203 at the bottom; a ball core 3 is installed in the valve body 1, the top of the ball core 3 is connected to the connecting section 203 at the bottom of the valve stem 2, the connecting section 203 is a flat square, and the flat square is inserted into the ball core 3, a left valve body cap 5 and a right valve body cap 6 are respectively installed on both sides of the valve body 1 by bolts 4, a downstream valve seat 7 and an upstream valve seat 8 are respectively installed between the two sides of the ball core 3 and the left valve body cap 5 and the right valve body cap 6, a butterfly spring 9 is pressed between the upstream valve seat 8 and the right valve body cap 6, and a valve seat sealing ring 10 is provided between the downstream valve seat 7 and the left valve body cap 5. The top and bottom ends of the left valve body cap 5 are respectively provided with sealing ring mounting grooves, and rubber O-rings 11 are respectively provided in the two sealing ring mounting grooves; the upstream valve seat 8 and the downstream valve seat 7 are respectively installed on both sides of the ball core 3, and a packing 14 is filled between the top of the valve body 1 and the valve stem 2, and a packing pad 16 is installed at the bottom of the packing 14. A packing pressure plate 15 is installed on the top surface of the valve body 1 through a packing bolt 17. The packing pressure plate 15 is a ring-shaped part with a T-shaped longitudinal section. The bottom of the packing pressure plate 15 extends into between the valve body 1 and the valve stem 2 to tightly press the packing 14; the bottom of the valve stem 2 is provided with a split ring 12; an anti-static combination 13 is also installed between the packing pad 16 and the split ring 12.

[0004] However, the sealing structure of this sealed ball valve requires time for the butterfly spring to stabilize upon reset, affecting the ball valve's sealing effectiveness and operational stability until the butterfly spring stabilizes. The split ring prevents blowout of the valve stem, but during rotation, the stem creates metal-to-metal sliding friction with the split ring. This increased friction increases the torque of the hard-seal ball valve, thus affecting its operational stability. The valve stem and ball are connected by a flat plate at the bottom of the stem, which is subject to significant stress and is prone to breakage, causing the entire stem to fly out, significantly reducing the ball valve's stability. Summary of the Invention

[0005] In view of the shortcoming of low stability of existing metal ball valves, the present invention provides a metal hard-sealed ball valve with high stability.

[0006] A metal hard-sealed ball valve comprises a valve body and a valve stem, the valve stem comprising a handle at the top, a stem in the middle and a connecting section at the bottom; a ball core is installed in the valve body, the connecting section at the bottom of the valve stem is inserted into the top of the ball core, a left valve body cap and a right valve body cap are respectively installed on both sides of the valve body by bolts, a downstream valve seat and an upstream valve seat are respectively installed between the two sides of the ball core and the left valve body cap and the right valve body cap, a valve seat sealing ring is provided between the downstream valve seat and the left valve body cap; a packing is filled between the top of the valve body and the stem, a packing pad is installed at the bottom of the packing, a packing pressure plate is installed on the top surface of the valve body by a packing bolt, the packing pressure plate is an annular member with a T-shaped longitudinal section, and the bottom of the packing pressure plate extends into between the valve body and the stem to tightly press the packing; it is characterized in that: The connecting section at the bottom of the valve stem is a threaded rod, on which a locking nut and a flat square sleeve are threadedly installed. The flat square sleeve and the flat square are fixedly connected by a set screw. A special structure spring is press-fitted between the upstream valve seat and the right valve body cap. The material of the special structure spring is an elastic thin plate. The special spring structure is an annular member. The special spring structure includes three sections, namely, from the inside to the outside, a first spring section, a second spring section, and a third spring section. The first spring section is cylindrical; the second spring section is frustoconical, with the diameter of its inner end being the same as that of the first spring section, and the diameter gradually increases from the inside to the outside; the longitudinal cross-section of the third spring section is "Z"-shaped, with the diameter of its inner end being larger than the diameter of the outer end of the second spring section. The outer end of the third spring section extends into the right valve body cap. A clamping angle is provided at the bottom of the outer end of the upstream valve seat. The clamping angle matches the shape of the first and second spring sections of the special structure spring, and the first and second spring sections are clamped to the clamping angle.

[0007] It is further characterized by: A sealing ring is pressed between the ball core and the upstream valve seat and the downstream valve seat. Sealing ring grooves are formed in the upstream valve seat and the downstream valve seat where they are close to the sealing rings. Lip-type metal sealing rings are installed in the sealing ring grooves. A metal O-ring and a valve seat sealing ring are pressed between the downstream valve seat and the left valve body cap. The bottom of the shaft is provided with a thrust ball bearing, and an anti-static assembly is installed between the filler pad and the thrust ball bearing; A packing gland is threadedly mounted on the top end of the rod, and the bottom end of the packing gland extends into the packing pressure plate and presses the packing pressure plate tightly; The third spring segment is provided with a protection hole.

[0008] After adopting the above-mentioned structure of the present invention, a special structure spring is used to seal the upstream valve seat, which can quickly restore performance without requiring a certain recovery and stabilization time. The preload of the special structure spring tends to be balanced, and the speed of valve opening and closing does not affect the preload value recovery performance, which greatly improves the valve preload stability and improves the performance of the ball valve product. The sealing of the downstream valve seat adopts a combination structure of the downstream valve seat, lip-type metal sealing ring, metal O-ring, valve seat sealing ring, and sealing ring, in which the metal O-ring and valve seat sealing ring have a dual sealing effect, which improves the stability of the ball valve from the perspective of improving the sealing effect. A packing gland is added between the valve stem and the packing pressure plate to prevent the valve stem from flying out due to the medium pressure in the valve body when the valve stem breaks, further increasing stability. The setting of the thrust ball bearing changes the sliding friction between the valve stem and the valve body into rolling friction, reducing mechanical wear and ensuring smooth operation of the valve. It mainly bears axial load, reduces the opening and closing torque of the ball valve, and extends the service life, thereby improving the stability of the ball valve. A flat square sleeve is set at the bottom of the valve stem, so that when the valve stem is subjected to excessive stress, only the flat square sleeve is broken instead of the valve stem itself, preventing the valve stem itself from flying out and further improving the stability of the ball valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a structural diagram of the prior art; Figure 2 It is a structural schematic diagram of the present invention; Figure 3 for Figure 2 Enlarged view of point A in the middle; Figure 4 This is a schematic diagram of the main view of the special spring structure; Figure 5 It is a schematic diagram of the side view of the special spring structure; Figure 6 This is a schematic diagram of the valve stem and ball core from the main view; Figure 7 A schematic diagram of a valve stem and a ball core from the side; Figure 8 A schematic diagram of a valve stem in the prior art viewed from above; Figure 9 This is a schematic diagram of the valve stem of the present invention when viewed from above. DETAILED DESCRIPTION

[0010] See Figure 2 、 Figure 3 A metal hard-sealed ball valve includes a valve body 1 and a valve stem 2. The valve stem 2 includes a handle section 201 at the top, a rod body 202 in the middle, and a connecting section 203 at the bottom.

[0011] A ball core 3 is installed in the valve body 1. The connecting section 203 at the bottom of the valve stem 2 is inserted into the top of the ball core 3. A left valve cap 5 and a right valve cap 6 are respectively installed on both sides of the valve body 1 via bolts 4. A downstream valve seat 7 and an upstream valve seat 8 are respectively installed between the left valve cap 5 and the right valve cap 6 on both sides of the ball core 3. A valve seat sealing ring 10 is provided between the downstream valve seat 7 and the left valve cap 5. A packing 14 is filled between the top of the valve body 1 and the stem 202, and a packing pad 16 is installed at the bottom of the packing 14. A packing pressure plate 15 is installed on the top surface of the valve body 1 through a packing bolt 17. The packing pressure plate 15 is a ring-shaped part with a T-shaped longitudinal section. The bottom of the packing pressure plate 15 extends into between the valve body 1 and the stem 202 to tightly press the packing 14.

[0012] See Figure 6 、 Figure 7 、 Figure 9 The connecting section 203 at the bottom of the valve stem 2 is a threaded rod, and a locking nut and a flat square sleeve 19 are threadedly installed on the threaded rod. The flat square sleeve 19 and the flat square are fixedly connected by a positioning screw 21.

[0013] See Figure 4 、 Figure 5 A special spring structure 26 is pressed between the upstream valve seat 8 and the right valve body cap 6. The material of the special spring structure 26 is an elastic thin plate, and the special spring structure 26 is a ring-shaped part. The special spring structure 26 includes three sections, which are, from the inside to the outside, a first spring section 261, a second spring section 262 and a third spring section 263. The first spring section 261 is cylindrical; the second spring section 262 is truncated cone-shaped, and the diameter of its inner end is the same as the diameter of the first spring section 261, and the diameter gradually increases from the inside to the outside; the longitudinal section of the third spring section 263 is a "Z" shape, and the diameter of its inner end is larger than the diameter of the outer end of the second spring section 262. The outer end of the third spring section 263 extends into the right valve body cap 6, and a clamping angle is provided at the bottom of the outer end of the upstream valve seat 8. The clamping angle matches the shape of the first spring section 261 and the second spring section 262 of the special spring structure 26, and the first spring section 261 and the second spring section 262 are clamped with the clamping angle.

[0014] The special spring structure 26 has excellent flexibility and elasticity, absorbing vibration and impact during ball valve operation. It matches the shape of the upstream valve seat 8 and extends into the right valve body cap 6, improving installation stability. The third spring segment 263 is provided with a protective hole 264 to reduce deformation caused by unnecessary stress, ensuring more stable performance.

[0015] A sealing ring 25 is pressed between the ball core 3 and the upstream valve seat 8 and the downstream valve seat 7. The sealing ring 25 is detachable. The sealing rings 25 on the left and right sides of the ball core 3 are symmetrical and interchangeable, making it easy to replace spare parts.

[0016] Sealing ring grooves are provided on the upstream valve seat 8 and the downstream valve seat 7 close to the sealing ring 25, and a lip-type metal sealing ring 20 is installed in the sealing ring groove; a metal O-ring 23 and a valve seat sealing ring 10 are pressed between the downstream valve seat 7 and the left valve body cap 5; the metal O-ring 23 and the valve seat sealing ring 10 have a double sealing effect, further improving the sealing effect and stability of the ball valve.

[0017] The bottom of the rod body 202 is provided with a thrust ball bearing 18. The setting of the thrust ball bearing 18 changes the sliding friction between the valve stem 2 and the valve body 1 into rolling friction, reducing mechanical wear and ensuring smooth operation of the valve. It mainly bears axial loads, reduces the opening and closing torque of the ball valve, and extends its service life.

[0018] An anti-static assembly 13 is also installed between the packing pad 16 and the thrust ball bearing 18 to prevent static electricity from being generated by friction of the ball valve.

[0019] A packing gland 27 is also threadedly installed on the top of the rod body 202, and the bottom end of the packing gland 27 extends into the packing pressure plate 15 and presses the packing pressure plate 15; the packing gland 27 is used to prevent the valve stem 2 from flying out due to the medium pressure in the valve body 1 when the valve stem 2 breaks, causing a safety accident.

[0020] 24 is the middle flange gasket in the figure.

Claims

1. A metal hard-sealed ball valve, comprising a valve body and a valve stem, wherein the valve stem comprises a handle at the top, a stem in the middle and a connecting section at the bottom; a ball core is installed in the valve body, and the connecting section at the bottom of the valve stem is inserted into the top of the ball core, a left valve body cap and a right valve body cap are respectively installed on both sides of the valve body by bolts, a downstream valve seat and an upstream valve seat are respectively installed between the two sides of the ball core and the left valve body cap and the right valve body cap, and a valve seat sealing ring is provided between the downstream valve seat and the left valve body cap; a packing is filled between the top of the valve body and the stem, a packing pad is padded at the bottom of the packing, a packing pressure plate is installed on the top surface of the valve body by a packing bolt, the packing pressure plate is an annular member with a T-shaped longitudinal section, and the bottom of the packing pressure plate extends into between the valve body and the stem to tightly press the packing; it is characterized in that: The connecting section at the bottom of the valve stem is a threaded rod, on which a locking nut and a flat square sleeve are threadedly installed. The flat square sleeve and the flat square are fixedly connected by a set screw. A special structure spring is press-fitted between the upstream valve seat and the right valve body cap. The material of the special structure spring is an elastic thin plate. The special spring structure is an annular member. The special spring structure includes three sections, namely, from the inside to the outside, a first spring section, a second spring section, and a third spring section. The first spring section is cylindrical; the second spring section is frustum-shaped, with the diameter of its inner end being the same as that of the first spring section, and the diameter gradually increases from the inside to the outside; the longitudinal cross-section of the third spring section is "Z"-shaped, with the diameter of its inner end being larger than the diameter of the outer end of the second spring section. The outer end of the third spring section extends into the right valve body cap. A clamping angle is provided at the bottom of the outer end of the upstream valve seat. The clamping angle matches the shape of the first and second spring sections of the special structure spring, and the first and second spring sections are clamped to the clamping angle.

2. A metal hard seal ball valve according to claim 1, characterized in that: A sealing ring is pressed between the ball core and the upstream valve seat and the downstream valve seat. Sealing ring grooves are provided on the upstream valve seat and the downstream valve seat close to the sealing rings, and a lip-type metal sealing ring is installed in the sealing ring groove; a metal O-ring and a valve seat sealing ring are pressed between the downstream valve seat and the left valve body cap.

3. A metal hard seal ball valve according to claim 2, characterized in that The bottom of the rod body is sleeved with a thrust ball bearing, and an anti-static assembly is installed between the filler pad and the thrust ball bearing.

4. A metal hard seal ball valve according to claim 3, characterized in that A packing gland is threadedly mounted on the top end of the rod body, and the bottom end of the packing gland extends into the packing pressure plate and presses the packing pressure plate.

5. The metal hard seal ball valve according to claim 1, characterized in that The third spring segment is provided with a protection hole.

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