CN217440831U

CN217440831U - LNG forced sealing switch ball valve

Info

Publication number: CN217440831U
Application number: CN202220503071.3U
Authority: CN
Inventors: 柴平海; 黄才文; 周超; 李世斌
Original assignee: Wuxi Smart Auto Control Engineering Co Ltd
Current assignee: Wuxi Smart Auto Control Engineering Co Ltd
Priority date: 2022-03-08
Filing date: 2022-03-08
Publication date: 2022-09-16
Anticipated expiration: 2032-03-08

Abstract

The utility model relates to a LNG forced seal switch ball valve, including valve body, valve gap, disk seat, valve ball, valve rod and packing subassembly, be provided with the valve ball in the valve body, the valve rod is provided with on the valve ball, the valve gap suit is in the valve rod outside and with valve body fixed connection, be provided with the packing box on the valve gap, be provided with the packing subassembly in the packing box; the method is characterized in that: the valve ball is characterized by also comprising a sealing ring, a first bushing, a second bushing and a plane bearing, wherein the sealing ring is arranged on one side of the valve ball, the first bushing is arranged between the upper end of the valve ball and the valve cover, and the second bushing is arranged between the lower end of the valve ball and the valve body; the lower extreme of valve rod is provided with the step, is provided with the flat bearing between step and the valve gap. The valve ball and the sealing ring of the utility model adopt a detachable combined structure, even if the sealing surface of the valve ball is worn, only the sealing ring needs to be replaced, and the maintenance cost is saved; the running torque of the valve is effectively reduced, the wear resistance is improved, and the service life is prolonged.

Description

LNG forced sealing switch ball valve

Technical Field

The utility model belongs to the technical field of instrument and meter, a LNG forced seal switch ball valve is related to.

Background

Liquefied Natural Gas (LNG) is short, the main component of the LNG is methane, the natural gas is purified and then is cooled to minus 162 ℃ through a cryogenic process to become liquid, and the volume of the LNG is reduced by 600 times. At present, the low-temperature ball valve for the LNG receiving station mainly depends on import from abroad, wherein the valve seat end surface of most low-temperature ball valves is sealed by an inlaid PCTFE sealing ring, and the valve seat is radially sealed by a low-temperature universal plug ring (modified PTFE). However, in the actual use process, since the temperature of LNG in the valve is-162 ℃, the thermal expansion coefficients of a valve ball, a valve seat, a PCTFE sealing ring and a low-temperature universal plug ring are different, so that the end face and the radial direction of the valve seat generate low-temperature leakage; meanwhile, as the PCTFE sealing ring and the valve ball are always contacted in the valve opening and closing process, the surface of the PCTFE sealing ring is abraded to generate leakage due to long-term frequent opening and closing; in addition, the low temperature ball valve of foreign import is mostly double valve seat seal structure, and the valve body intracavity is easy to hold back partial LNG medium, can lead to in it to hold back LNG to be heated and turn into gaseous when the intracavity temperature accident rises to the normal atmospheric temperature, and volume expansion 600 is doubly, and intracavity pressure risees unusually, can lead to the valve gasket to leak outward, the risk of valve explosion can appear even, and the device is forced the shut down operation so that maintain or change the valve, causes unnecessary economic loss and time waste.

Disclosure of Invention

The utility model aims to overcome the defects in the prior art, improve the low temperature resistance and the abrasion resistance of the LNG low-temperature ball valve, and prevent the pressure build-up in the valve cavity; the opening and closing torque of the valve is reduced, and the service life is prolonged; guarantee device safety, stable, high-efficient operation, provide a canned type switch ball valve is forced to LNG.

In order to realize the purpose, the following technical scheme is adopted:

an LNG forced sealing switch ball valve comprises a valve body, a valve cover, a valve seat, a valve ball, a valve rod and a packing assembly, wherein the valve ball is arranged in the valve body, the upper end of the valve ball is provided with the valve rod, the valve cover is sleeved on the outer side of the valve rod and is fixedly connected with the valve body, the valve cover is provided with a packing box, and the packing assembly is arranged in the packing box; the method is characterized in that: the valve ball is provided with a sealing ring and a first Luo Di firm gasket, the valve seat, the pressing ring and the second Luo Di firm gasket are sequentially fastened in a seat cavity of the valve body, the valve ball and the second bushing are arranged in a shaft hole at the bottom of the valve body, the valve rod is sleeved in a tenon groove of the valve ball and is screwed into the valve seat, the first bushing is arranged between the upper end of the valve ball and the valve cover, and the second bushing is positioned between the lower end of the valve ball and the valve body; the lower end of the valve rod is provided with a step, a plane bearing is arranged between the step and the valve cover, and the plane bearing is sleeved on the step of the valve rod.

Preferably, the sealing ring is mounted on the valve ball by using a hexagon socket head cap screw and a Luo Di's gasket, and a winding gasket is arranged between the sealing ring and the valve ball.

Preferably, the valve cover and the valve body are fixedly connected through bolts, and a winding gasket is arranged between the valve cover and the valve body.

Preferably, the packing assembly comprises a universal plug ring, a retainer ring, packing, a packing spacer ring, a packing pressing sleeve and a packing pressing plate which are sequentially arranged in the packing box, the packing pressing plate is fixed with the valve cover through bolt connection, and the bolt connection is fastened through a disc spring.

Preferably, the rotation center of the valve ball and the geometric center of the sealing ring are eccentrically arranged, and the rotation center of the valve ball and the center of the valve body flow passage are eccentrically arranged.

Preferably, the sealing ring is of a spherical crown shape.

Preferably, the contact surface of the valve seat and the valve body is a conical surface.

Preferably, a water dropping plate is arranged on the valve cover.

Preferably, the valve cover is provided with a pressure relief hole.

Compared with the prior art, the utility model, have following advantage:

1. the utility model discloses a valve ball, sealing ring adopt detachable integrated configuration, even if the sealed face of valve ball takes place wearing and tearing, only need change the sealing ring, practice thrift cost of maintenance.

2. The utility model discloses a valve ball adopts two eccentric designs, and the valve ball does "rotation + translation" dual vector cam motion around the centre of rotation, and the in-process valve ball that the valve opened, closed promptly and disk seat zero contact improve the wear resistance with the operation moment of torsion of effectual reduction valve, especially are fit for needing the LNG operating mode of frequent switch.

3. The utility model discloses a disk seat installation and maintenance, maintenance convenience need not the installation of making the disk seat very much and dismantles the frock for conventional LNG ball valve.

4. The utility model discloses a valve rod drive valve ball produces the mechanical forced seal of cam wedging with the disk seat, need not rely on fluid pressure just can realize two-way tight cutting off, is particularly suitable for the LNG operating mode that needs the two-way sealed requirement.

5. The utility model discloses a ball valve structure has single disk seat, and open valve pocket can not hold back the LNG medium among the switching process, stops the risk of suppressing pressure in the valve pocket of LNG low temperature ball valve from the root, ensures that the valve is safe, reliable of essence.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

Fig. 2 is a schematic diagram of the valve cover structure of the present invention.

Fig. 3 is a schematic view of the installation of the valve ball and the sealing ring of the present invention.

In the figure: 1. a valve body; 2. a valve cover; 3. a valve seat; 4. a valve ball; 5. a valve stem; 6. a stuffing box; 7. a first bushing; 8. a second bushing; 9. a flat bearing; 10. a step; 11. a socket head cap screw; 12. a first Luo Di firmly pad; 13. a first winding shim; 14. a stopper ring; 15. a retainer ring; 16. a filler; 17. a packing spacer ring; 18. pressing and sleeving the filler; 19. a packing press plate; 20. a fastening screw; 21. 22, a second winding gasket; 23. a seal ring; 24. a weep board; 25. a pressure relief vent; 26. a seal ring; 27. pressing a ring; 28. a disc spring.

The specific implementation mode is as follows:

in order to make the technical solutions of the present invention better understood by those skilled in the art, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall belong to the protection scope of the present invention.

As shown in fig. 1-3, an LNG forced sealing switch ball valve comprises a valve body 1, a valve cover 2, a valve seat 3, a valve ball 4, a valve rod 5 and a packing assembly, wherein the valve ball 4 is arranged in the valve body 1, the valve rod 5 is arranged at the upper end of the valve ball 4, the valve cover 2 is sleeved outside the valve rod 5 and is fixedly connected with the valve body 1, a packing box 6 is arranged in the valve cover 2, and the packing assembly is arranged in the packing box 6; the method is characterized in that: the valve ball 4 is provided with the sealing ring 23 and a first Luodi gasket 12, the valve seat 3, a pressing ring 27 and a second Luodi gasket 21 are sequentially fastened in a seat cavity of the valve body 1, the pressing ring 27 is used for fastening the valve seat 3, the valve seat 3 cannot fall off in the seat cavity, the fastening screw 20 is used for fixing the pressing ring 27, and the second Luodi gasket 21 prevents the fastening screw 20 from loosening; the valve ball 4 and the second bushing 8 are arranged in a shaft hole at the bottom of the valve body 1, the valve rod 5 is sleeved in a tenon groove of the valve ball 4, and the valve ball 4 is screwed into the valve seat;

a first bushing 7 is arranged between the upper end of the valve ball 4 and the valve cover 2, and a second bushing 8 is positioned between the lower end of the valve ball 4 and the valve body 1; the outer sides of the first bushing 7 and the second bushing 8 are respectively provided with a bushing seat, the bushing seats are sleeved on the valve ball, the lower end of the valve rod 5 is provided with a step 10, a plane bearing 9 is arranged between the step 10 and the valve cover 2, and the plane bearing 9 is sleeved on the step of the valve rod 5; the flat bearing 9 reduces the friction when the valve stem 5 is rotated.

Further, the sealing ring 23 is installed on the valve ball 4 by using the socket head cap screw 11 and the first luodi gasket 12, the first luodi gasket 12 is used for preventing the socket head cap screw 11 from loosening, so that the connection is more tight, the second winding gasket 22 is arranged between the sealing ring 23 and the valve ball 4, and the second winding gasket 13 is used for sealing between the sealing ring 23 and the valve ball 4. A sealing ring 26 is arranged between the valve seat 3 and the sealing ring 23 for sealing.

Further, the valve cover 2 and the valve body 1 are fixedly connected through bolts, a first winding gasket 13 is arranged between the valve cover 2 and the valve body 1, and the first winding gasket 13 is used for sealing between the valve cover 2 and the valve body 1.

Further, the packing assembly comprises a universal plug ring 14, a retainer ring 15, packing 16, a packing spacer ring 17, a packing pressing sleeve 18 and a packing pressing plate 19 which are sequentially arranged in the packing box 6, the packing pressing plate 19 is fixedly connected with the valve cover 2 through bolts and a disc spring 28, and the packing assembly is used for sealing between the valve cover 2 and the valve rod 5.

Furthermore, the rotation center of the valve ball 4 and the geometric center of the sealing ring 23 are eccentrically arranged, the rotation center of the valve ball 4 and the center of the flow channel of the valve body 1 are eccentrically arranged, and the double-eccentric design of the valve ball 4 ensures that the valve ball 4 is not in contact with a valve seat in the opening and closing process, the sealing surface is almost zero in abrasion, and the service life of the valve is prolonged.

Further, the sealing ring 23 is of a spherical crown shape.

Furthermore, the contact surface of the valve seat 3 and the valve body 1 is a conical surface.

Furthermore, the valve cover 2 is provided with a water dropping plate 24, and the water dropping plate 24 is used for preventing the moisture in the air from being liquefied into water at low temperature and dropping on the gasket of the valve body flange, so that the gasket is prevented from being damaged by freezing water drops.

Further, a pressure relief hole 25 is formed in the valve cover 2.

The working principle is as follows: because the valve ball adopts a double-eccentric design, when the valve rod is rotated anticlockwise to open the valve ball, the valve ball makes cam motion and is separated from the valve seat immediately after being opened, the whole opening process is not in contact with the valve seat, and the running torque of the valve is effectively reduced; when the valve rod is rotated clockwise to close the valve ball, the valve ball does cam motion in the same way, the whole closing process is not in contact with the valve seat, and mechanical forced sealing is realized by means of the torque of the actuating mechanism until the closing end point, so that the bidirectional sealing performance of the valve is ensured.

Because the valve ball adopts the double eccentric design, the valve ball and the valve seat are not contacted in the opening and closing processes of the valve, the sealing surface is almost zero abraded, and the valve seat and the sealing ring are subjected to surface hardening treatment, so that the valve is particularly suitable for occasions requiring frequent opening and closing of LNG, and the service life of the valve is effectively prolonged.

Because the valve adopts a single valve seat structure and an open valve cavity, the low-temperature medium cannot be intercepted by the cavity in the valve body in the opening and closing processes of the valve, and the safe and reliable operation of the LNG device is ensured.

It is to be understood that the above embodiments are merely exemplary embodiments that have been employed to illustrate the principles of the present invention, and that the present invention is not limited thereto. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit and substance of the invention, and these modifications and improvements are also considered to be within the scope of the invention.

Claims

1. An LNG forced sealing switch ball valve comprises a valve body (1), a valve cover (2), a valve seat (3), a valve ball (4), a valve rod (5) and a packing assembly, wherein the valve ball (4) is arranged in the valve body (1), the valve cover (2) is sleeved on the outer side of the valve rod (5) and fixedly connected with the valve body (1), a packing box (6) is arranged in the valve cover (2), and the packing assembly is arranged in the packing box (6); the method is characterized in that: the valve ball is characterized by further comprising a sealing ring (23), a first bushing (7), a second bushing (8) and a plane bearing (9), wherein the sealing ring (23) and a first Luodi firm gasket (12) are arranged on the valve ball (4), the valve seat (3), the pressing ring (27) and the second Luodi firm gasket (21) are sequentially fastened in a seat cavity of the valve body (1), the valve ball (4) and the second bushing (8) are installed in a shaft hole at the bottom of the valve body (1), the valve rod (5) is sleeved in a tenon groove of the valve ball (4) and is screwed into the valve seat, the first bushing (7) is arranged between the upper end of the valve ball (4) and the valve cover (2), and the second bushing (8) is located between the lower end of the valve ball (4) and the valve body (1); the lower end of the valve rod (5) is provided with a step (10), a plane bearing (9) is arranged between the step (10) and the valve cover (2), and the plane bearing (9) is sleeved on the step of the valve rod (5).

2. An LNG forced sealing on-off ball valve as claimed in claim 1, wherein: the sealing ring (23) is arranged on the valve ball (4) through a hexagon socket head cap screw (11) and a first Luo Di's gasket (12), and a second winding gasket (22) is arranged between the sealing ring (23) and the valve ball (4).

3. An LNG forced-sealing on-off ball valve as claimed in claim 1, wherein: the valve cover (2) and the valve body (1) are fixedly connected through bolts; and a first winding gasket (13) is arranged between the valve cover (2) and the valve body (1).

4. An LNG forced-sealing on-off ball valve as claimed in claim 1, wherein: the packing assembly comprises a universal plug ring (14), a retainer ring (15), packing (16), a packing spacer ring (17), a packing pressing sleeve (18) and a packing pressing plate (19) which are sequentially arranged in a packing box (6), and the packing pressing plate (19) is fixed with the valve cover (2) by bolts and disk springs (28).

5. An LNG forced-sealing on-off ball valve as claimed in claim 1, wherein: the rotary center of the valve ball (4) and the center of the sealing ring (23) are eccentrically arranged, and the rotary center of the valve ball (4) and the center of the flow channel of the valve body (1) are eccentrically arranged.

6. An LNG forced sealing on-off ball valve as claimed in claim 1, wherein: the sealing ring (23) is in a spherical crown shape.

7. An LNG forced sealing on-off ball valve as claimed in claim 1, wherein: the contact surface of the valve seat (3) and the valve body (1) is a conical surface.

8. An LNG forced-sealing on-off ball valve as claimed in claim 1, wherein: the valve cover (2) is provided with a water dropping plate (24).

9. An LNG forced-sealing on-off ball valve as claimed in claim 1, wherein: the valve cover (2) is provided with a pressure relief hole (25).