Underwater ball valve rod sealing structure and sealing verification method
Through multiple sets of sealing structures and seal verification methods, the underwater ball valve stem sealing structure achieves long-term maintenance-free and seal reliability under high pressure environments, solving the stability and verification problems of sealing structures in the existing technology, and ensuring the valve stem Sealing performance within 20 years.
Patent Information
- Application Number
- CN202310773616.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-28
- Publication Date
- 2024-12-31
AI Technical Summary
The underwater ball valve stem sealing structure needs to maintain reliability and stability in long-term maintenance-free and high-pressure environments. The existing single-stage sealing structure is difficult to meet this requirement and there is a lack of effective seal verification methods.
Multiple groups of sealing structures are adopted, including filler box, gland, filler assembly and seal verification channel. Through multiple groups of sealing structures such as upper Y-ring, lower Y-ring, filler, lip ring, etc., they independently detect and withstand internal and external pressures, combined with the disc Spring and threaded connections enable seal compensation and verification.
It realizes maintenance-free seal reliability over a 20-year life cycle, avoids leakage, provides an independent seal verification method, and improves the dynamic seal reliability and stability of the valve stem.
Smart Images
Figure CN119222385A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to a valve stem sealing structure and a sealing verification method, and in particular relates to an underwater ball valve stem sealing structure and a sealing verification method. Background Art
[0002] The working condition of conventional ball valves is to bear only the internal pressure of the medium. The valve stem sealing structure only has the function of preventing internal pressure. Conventional ball valves have no special requirements for design life. The valve stem adopts a single-stage seal, that is, a set of packing seals. During the use of the valve, it is necessary to maintain or tighten the packing plate bolts to compensate for the loosening of the packing. The working condition of underwater ball valves is to bear both the internal pressure of the medium and the external pressure of seawater. This requires the valve stem structure to be able to withstand both the internal pressure from the valve cavity medium and the external pressure from deep water; underwater ball valves have special requirements for design life, generally maintenance-free for more than 20 years, and it is strictly forbidden to discharge to the environment. In order to meet the requirements of long-term reliable sealing, it is necessary to improve the reliability and stability of the dynamic seal at the valve stem.
[0003] In order to meet the long-term maintenance-free and reliability requirements of underwater ball valve stem seals, a new ball valve stem seal structure is required, and this seal structure has been verified. Summary of the invention
[0004] In view of the defects of the prior art, the present invention provides a sealing structure of an underwater ball valve stem and a sealing verification method.
[0005] The present invention is implemented as follows: an underwater ball valve stem sealing structure, which includes a stuffing box, a gland is arranged above the stuffing box, the stuffing box and the gland are fixedly connected, the valve stem passes through the stuffing box and the gland, and a filling assembly is arranged between the valve stem and the stuffing box.
[0006] An underwater ball valve stem sealing structure as described above, wherein the filling assembly includes an upper bearing, a press sleeve, a disc spring, an upper Y-shaped ring, a lower Y-shaped ring, a packing, a packing pad, a lip ring, and a lower bearing which are sequentially sleeved along the outer side wall of the valve stem from top to bottom, wherein the press sleeve is a cylindrical structure with a boss in the middle, the outer contour shape of the upper surface of the press sleeve matches the shape of the lower surface of the pressure cover, a disc spring is arranged between the press sleeve and the pressure cover, an upper groove and a lower groove of the press sleeve are opened on the boss of the press sleeve, the upper Y-shaped ring is arranged in the upper groove of the press sleeve, the lower Y-shaped ring is arranged in the lower groove of the press sleeve, and the packing pad is an inverted "convex" shaped part.
[0007] As described above, an underwater ball valve stem sealing structure, wherein the press sleeve is provided with two inner and outer grooves, namely, a press sleeve outer guide groove and a press sleeve inner guide groove, and is provided with a press sleeve guide hole, the press sleeve guide hole connects the press sleeve outer guide groove and the press sleeve inner guide groove, and the press sleeve guide hole is connected with the upper detection hole of the stuffing box to form a sealing verification channel.
[0008] As described above, an underwater ball valve stem sealing structure, wherein the packing pad is provided with two inner and outer grooves, namely, an outer guide groove of the packing pad and an inner guide groove of the packing pad, and a packing pad guide hole is provided, the packing pad guide hole connects the outer guide groove of the packing pad and the inner guide groove of the packing pad, and the packing pad guide hole is connected with the lower detection hole of the stuffing box to form a sealing verification channel.
[0009] As described above, an underwater ball valve stem sealing structure, wherein the stuffing box is a hollow cylindrical part, a plurality of steps are arranged in the hollow part, the shape and size of the steps match the shape of the filling component sleeved on the outer wall of the valve stem, and a lower detection hole and an upper detection hole are respectively opened on the side walls of the stuffing box, the lower detection hole is connected to the packing pad guide hole of the packing pad, and the upper detection hole is connected to the pressure sleeve guide hole.
[0010] A method for verifying the seal of an underwater ball valve stem includes the following steps: respectively testing the pressure bearing capacity of an upper Y-shaped ring, a lower Y-shaped ring, a packing, and a lip ring.
[0011] A method for verifying the seal of an underwater ball valve stem as described above includes the following contents: A method for verifying that the lower Y-ring can withstand the internal pressure alone is achieved by applying 1.1 times the valve design pressure through the detection hole on the upper side of the stuffing box, maintaining the pressure for 15 minutes, and checking the leakage of the gland stem hole. No visible leakage is considered acceptable.
[0012] A method for verifying the seal of an underwater ball valve stem as described above includes the following contents: a method for verifying that the upper Y-ring can withstand external pressure alone is achieved by applying a pressure 1.5 times the design water depth of the valve through the gland valve stem hole, maintaining the pressure for 15 minutes, and checking the leakage of the detection hole on the upper side of the stuffing box. No visible leakage is considered acceptable.
[0013] A method for verifying the seal of an underwater ball valve stem as described above includes the following contents: a method for verifying that the packing can withstand internal pressure alone is implemented as follows: a pressure 1.1 times the design pressure of the valve is applied through the detection hole on the lower side of the stuffing box, the pressure is maintained for 15 minutes, and the leakage of the detection hole on the upper side of the stuffing box is checked. The test is qualified if there is no visible leakage; a method for verifying that the packing can withstand external pressure alone is implemented as follows: a pressure 1.5 times the design water depth of the valve is applied through the detection hole on the upper side of the stuffing box, the pressure is maintained for 15 minutes, and the leakage of the detection hole on the lower side of the stuffing box is checked. The test is qualified if there is no visible leakage.
[0014] A method for verifying the seal of an underwater ball valve stem as described above includes the following contents: a method for verifying that the lip ring can withstand the internal pressure alone is implemented as follows: the valve is half-open and 1.1 times the valve design pressure is applied to the channel, the pressure is maintained for 15 minutes, and the leakage of the detection hole on the lower side of the stuffing box is checked. No visible leakage is considered acceptable.
[0015] The significant effects of the present invention are: a single-group sealing valve stem structure requires frequent maintenance, while the present invention adopts a multi-group sealing structure, which is maintenance-free within the 20-year life cycle of the valve; compared with the single-group sealing valve stem structure, which is prone to leakage, the multi-group sealing solves this problem and achieves sealing reliability throughout the entire life cycle. A method for independent detection of multiple-group sealing of valve stems is also provided. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 A schematic diagram of an underwater ball valve stem sealing structure and a sealing verification method.
[0017] Figure 2 Schematic diagram of the gland.
[0018] Figure 3 Schematic diagram of packing pad.
[0019] Figure 4 Schematic diagram of the compression sleeve.
[0020] Figure 5 Schematic diagram of valve body stuffing box.
[0021] In the figure: 1, valve stem, 2, gland, 3, upper bearing, 4, gland, 5, disc spring, 6, external pressure Y-ring, 7, internal pressure Y-ring, 8, packing, 9, packing pad, 10, lip ring, 11, lower bearing, 12, stuffing box, 13, hexagon socket screw, 21, inner side of gland, 22, gland step surface, 41, upper groove of gland, 42, outer guide groove of gland, 43, inner guide groove of gland, 44, guide hole of gland, 45, lower groove of gland, 91, guide hole of packing pad, 92, outer guide groove of packing pad, 93, inner guide groove of packing pad, 121, threaded hole, 122, upper step surface of stuffing box, 123, lower step surface of stuffing box, 124, inner side of stuffing box, 125, lower detection hole, 126, upper detection hole. DETAILED DESCRIPTION
[0022] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.
[0023] A underwater ball valve stem sealing structure and sealing verification method, such as Figure 1 As shown, it includes a valve stem 1, a gland 2, an upper bearing 3, a compression sleeve 4, a disc spring 5, an upper Y-shaped ring 6, a lower Y-shaped ring 7, a packing 8, a packing gasket 9, a lip ring 10, a lower bearing 11, a stuffing box 12, and a hexagon socket screw 13. Among them, the multiple sets of seals include a lip ring seal 10, a packing seal 8, a lower Y-shaped ring 7 and an upper Y-shaped ring 6 seal.
[0024] The underwater ball valve stem sealing structure and sealing verification method, wherein: Figure 1 , Figure 2 , Figure 5As shown, a disc spring is provided between the gland 2 and the pressing sleeve 4; the pressing sleeve 4 is clamped on the gland step surface 22 to ensure that the height of the disc spring 5 is within the pre-compression design range after assembly, thereby realizing the anti-loosening of the packing 8, that is, the compensation function; the stuffing box 12 is provided with a threaded hole 121, which is connected to the gland 2 by a hexagon socket screw 13 to realize the pre-tightening of the packing 8.
[0025] The underwater ball valve stem sealing structure and sealing verification method, wherein: Figure 1 , Figure 2 , Figure 5 As shown, an upper bearing 3 matching the valve stem 1 is provided on the inner side 21 of the gland, and a lower bearing 11 matching the valve stem 1 is provided on the inner side 124 of the stuffing box; and the upper and lower bearings are arranged at the same diameter position of the valve stem to achieve precise guiding and positioning of the valve stem sealing position.
[0026] The underwater ball valve stem sealing structure and sealing verification method, wherein: Figure 1 , Figure 4 , Figure 5 As shown, the pressing sleeve 4 is arranged on the upper step surface 122 of the stuffing box to transfer the bolt preload force acting on the stuffing box 8; the pressing sleeve 4 is provided with space for installing the lower Y-shaped ring 7 and the upper Y-shaped ring 6 respectively, namely the upper groove 41 of the pressing sleeve and the lower groove 45 of the pressing sleeve, wherein the lower Y-shaped ring 7 bears the internal pressure alone, and the upper Y-shaped ring 6 bears the external pressure alone; the pressing sleeve 4 is provided with two inner and outer grooves, namely the pressing sleeve outer guide groove 42 and the pressing sleeve inner guide groove 43, and is provided with a pressing sleeve guide hole 44, which is connected with the upper detection hole 126 of the stuffing box to form a sealing verification channel.
[0027] The underwater ball valve stem sealing structure and sealing verification method, wherein: Figure 1 As shown, the packing 8 is located below the compression sleeve 4 and above the packing pad 9 in the space of the stuffing box 12, and can withstand the internal pressure and the external pressure independently.
[0028] The underwater ball valve stem sealing structure and sealing verification method, wherein: Figure 1 , Figure 3 , Figure 5 As shown, the stuffing pad 9 is arranged on the lower step surface 123 of the stuffing box; the stuffing pad 9 is provided with two inner and outer grooves, namely a stuffing pad outer guide groove 92 and a stuffing pad inner guide groove 93, and a stuffing pad guide hole 91 is provided, which is connected with the lower detection hole 125 of the stuffing box to form a sealing verification channel.
[0029] The underwater ball valve stem sealing structure and sealing verification method, wherein: Figure 1 As shown, a lip ring 10 is provided in the space between the stuffing box 12 and the stuffing pad 9, which can withstand the internal pressure independently.
[0030] The underwater ball valve stem sealing structure and sealing verification method, wherein the Y-ring sealing verification method. The verification method that the lower Y-ring 7 bears the internal pressure alone is implemented as follows: 1.1 times the valve design pressure is applied through the detection hole 126 on the upper side of the stuffing box, the pressure is maintained for 15 minutes, and the leakage of the valve stem hole of the gland 2 is checked. If there is no visible leakage, it is qualified. The verification method that the upper Y-ring 6 bears the external pressure alone is implemented as follows: 1.5 times the valve design water depth pressure is applied through the valve stem hole of the gland 2, the pressure is maintained for 15 minutes, and the leakage of the detection hole 126 on the upper side of the stuffing box is checked. If there is no visible leakage, it is qualified.
[0031] The underwater ball valve stem sealing structure and sealing verification method, wherein the packing sealing verification method. The verification method for packing 8 to withstand internal pressure alone is implemented as follows: 1.1 times the valve design pressure is applied through the lower detection hole 125 of the stuffing box, the pressure is maintained for 15 minutes, and the leakage of the upper detection hole 126 of the stuffing box is checked. If there is no visible leakage, it is qualified. The verification method for packing 8 to withstand external pressure alone is implemented as follows: 1.5 times the valve design water depth pressure is applied through the upper detection hole 126 of the stuffing box, the pressure is maintained for 15 minutes, and the leakage of the lower detection hole 125 of the stuffing box is checked. If there is no visible leakage, it is qualified.
[0032] The lip ring sealing verification method is as follows: the valve is half-opened and the passage is subjected to 1.1 times the valve design pressure, the pressure is maintained for 15 minutes, and the leakage of the detection hole 125 on the lower side of the stuffing box is checked. If there is no visible leakage, it is qualified.
Claims
1. An underwater ball valve stem sealing structure, characterized in that: The invention comprises a stuffing box (12), a gland (2) is arranged above the stuffing box (12), the stuffing box (12) and the gland (2) are fixedly connected, a valve stem (1) passes through the stuffing box (12) and the gland (2), and a stuffing assembly is arranged between the valve stem (1) and the stuffing box (12).
2. The underwater ball valve stem sealing structure according to claim 1, characterized in that: The filling assembly comprises an upper bearing (3), a pressing sleeve (4), a disc spring (5), an upper Y-shaped ring (6), a lower Y-shaped ring (7), a filler (8), a filler pad (9), a lip ring (10), and a lower bearing (11) which are sequentially sleeved along the outer wall of the valve stem (1) from top to bottom, wherein the pressing sleeve (4) is a cylindrical structure with a boss in the middle, the outer contour shape of the upper surface of the pressing sleeve (4) matches the shape of the lower surface of the pressure cover (2), a disc spring (5) is arranged between the pressing sleeve (4) and the pressure cover (2), the boss of the pressing sleeve (4) is provided with a pressing sleeve upper groove (41) and a pressing sleeve lower groove (45), the upper Y-shaped ring (6) is arranged in the pressing sleeve upper groove (41), the lower Y-shaped ring (7) is arranged in the pressing sleeve lower groove (45), and the filler pad (9) is an inverted "convex" shaped part.
3. The underwater ball valve stem sealing structure according to claim 2, characterized in that: The pressing sleeve (4) is provided with two inner and outer grooves, namely, an outer guide groove (42) of the pressing sleeve and an inner guide groove (43) of the pressing sleeve, and is provided with a pressing sleeve guide hole (44). The pressing sleeve guide hole (44) is connected with the outer guide groove (42) of the pressing sleeve and the inner guide groove (43). The pressing sleeve guide hole (44) is connected with the upper detection hole (126) of the stuffing box (12) to form a sealing verification channel.
4. The underwater ball valve stem sealing structure according to claim 3, characterized in that: The packing pad (9) is provided with two inner and outer grooves, namely, an outer packing pad flow guide groove (92) and an inner packing pad flow guide groove (93), and is provided with a packing pad flow guide hole (91). The packing pad flow guide hole (91) is connected with the outer packing pad flow guide groove (92) and the inner packing pad flow guide groove (93). The packing pad flow guide hole (91) is connected with the lower detection hole (125) of the stuffing box (12) to form a sealing verification channel.
5. The underwater ball valve stem sealing structure according to claim 4, characterized in that: The stuffing box (12) is a hollow cylindrical part, and a plurality of steps are arranged in the hollow part. The shape and size of the steps match the shape of the filling component sleeved on the outer wall of the valve stem (1). The side wall of the stuffing box (12) is respectively provided with a lower detection hole (125) and an upper detection hole (126). The lower detection hole (125) is connected to the packing pad guide hole (91) of the packing pad (9), and the upper detection hole (126) is connected to the compression sleeve guide hole (44).
6. A method for verifying the seal of an underwater ball valve stem, characterized in that: The method comprises the following contents: respectively carrying out pressure bearing tests on the upper Y-shaped ring (6), the lower Y-shaped ring (7), the filler (8) and the lip ring (10).
7. A method for verifying the seal of an underwater ball valve stem as claimed in claim 6, characterized in that: The following contents are included: the verification method of the lower Y-ring (7) independently bearing the internal pressure is realized as follows: 1.1 times the valve design pressure is applied through the detection hole (126) on the upper side of the stuffing box, the pressure is maintained for 15 minutes, and the leakage of the valve stem hole of the gland (2) is checked. If there is no visible leakage, it is qualified.
8. A method for verifying the seal of an underwater ball valve stem as claimed in claim 6, characterized in that: The following contents are included: the verification method of whether the upper Y-ring (6) can withstand external pressure alone is realized as follows: 1.5 times the designed water depth pressure of the valve is applied through the valve stem hole of the gland (2), the pressure is maintained for 15 minutes, and the leakage of the detection hole (126) on the upper side of the stuffing box is checked. If there is no visible leakage, it is qualified.
9. A method for verifying the seal of an underwater ball valve stem as claimed in claim 6, characterized in that: The invention comprises the following contents: a verification method for the packing (8) to withstand internal pressure alone is implemented as follows: 1.1 times the valve design pressure is applied through the detection hole (126) on the lower side of the packing box, the pressure is maintained for 15 minutes, and the leakage of the detection hole (126) on the upper side of the packing box is checked. If there is no visible leakage, it is qualified; a verification method for the packing (8) to withstand external pressure alone is implemented as follows: 1.5 times the valve design water depth pressure is applied through the detection hole (126) on the upper side of the packing box, the pressure is maintained for 15 minutes, and the leakage of the detection hole (125) on the lower side of the packing box is checked. If there is no visible leakage, it is qualified.
10. A method for verifying the seal of an underwater ball valve stem as claimed in claim 6, characterized in that: The invention comprises the following contents: the verification method of the lip ring (10) independently bearing the internal pressure is realized as follows: the valve is half-opened and 1.1 times of the valve design pressure is applied to the passage, the pressure is maintained for 15 minutes, and the leakage of the detection hole (125) on the lower side of the stuffing box is checked. If there is no visible leakage, it is qualified.