CN206361185U - A kind of cryogenic ball valve - Google Patents

Abstract

The utility model relates to a low-temperature ball valve, which is characterized in that it includes a valve body, a connecting body, a valve stem, a valve core, a valve cover, a packing gland, a valve body, a packing cover, and a handle. There is a spring at the bottom of the valve seat at the inlet end of the body, and a through hole connected to the inside of the valve core is opened on the side of the valve core as a pressure balance hole. Placed on the sealing ring of the valve seat, the valve stem is connected with the valve core, a lip sealing ring is installed at the stuffing box of the bonnet, and a stuffing cap is installed above the bonnet. The utility model solves the danger of leakage of dangerous gas or liquid in the existing low-temperature ball valve due to rupture due to overpressure, and the inherent elastic effect of low-temperature-resistant materials will be greatly reduced under low-temperature and ultra-low-temperature working conditions. And affected by low temperature deformation.

Description

A low temperature ball valve

technical field

The utility model relates to a low temperature ball valve.

Background technique

Ball valves are mainly used for fluid or gas pipeline transmission, blocking fluid or gas for maintenance, overhaul or construction, and are widely used in petroleum refining, long-distance pipelines, chemical industry, papermaking, water conservancy, electric power and other industries. Growth, the application of cryogenic valves and ultra-low temperature valves is becoming more and more extensive.

Since the cryogenic ball valve is used in a low-temperature environment, the ball valve is closed from open to closed, and the middle cavity has consistent pressure. After the valve is closed, the cavity in the valve body is a sealed space, and the pressure in the middle cavity will not flow, and the low-temperature liquid will vaporize. The pressure in the cavity rises sharply. Since the cryogenic ball valves in the prior art adopt two-way sealing without pressure relief function, the ball valve will rupture due to overpressure, causing the danger of dangerous gas or liquid leakage in it, and the cryogenic liquid Vaporization will impact the packing seal structure set in the valve stem along the gap between the valve stem and the connecting rod, and will also impact the sealing gasket along the connecting body, causing the packing seal and connection seal to fail , greatly shortening its service life. Moreover, most of the existing technologies simply change the material of the valve into a low-temperature-resistant material, but even if the low-temperature-resistant material is used in low-temperature and ultra-low temperature conditions, its inherent elastic effect will be greatly reduced, and it will be affected by low-temperature deformation. . However, the seat sealing surfaces of ordinary cryogenic ball valves and ultra-low temperature ball valves are flat seals, and the sealing ring material cannot automatically compensate for the impact of low temperature deformation under low temperature and ultra low temperature conditions, thereby affecting the sealing performance of the valve.

Contents of the invention

The utility model provides a low-temperature ball valve, which aims to solve the problem that the ball valve in the prior art will be ruptured due to overpressure, resulting in the danger of dangerous gas or liquid leakage and the sealing ring material cannot automatically compensate for low temperature under low temperature and ultra-low temperature conditions. The influence of deformation in turn affects the sealing performance of the valve.

The utility model scheme is as follows:

A low-temperature ball valve, including a valve body, a connecting body, a valve stem, a valve core, a valve cover, a packing gland, and a handle. , the valve body is equipped with a lip seal ring installation groove and a metal winding pad installation groove, the valve seat in the valve body is provided with a valve seat seal ring, a spring is installed under the valve seat seal ring, the valve core is set on the valve seat seal ring, and the valve core A through hole connected to the inside of the valve core is opened on the side as a pressure balance hole. The valve stem is connected to the valve core. There is a metal wound gasket between the valve body and the valve stem, an electrostatic spring and a steel ball are installed between the valve cover and the valve stem, a lip seal ring is installed at the stuffing box of the valve cover, and a stuffing cover is installed above the valve cover.

Further, the stuffing box of the bonnet also includes a packing group and a packing pad, the packing pad is arranged on the lip sealing ring, and the packing group is arranged on the packing pad;

Further, the valve core is provided with a groove for fixing with the valve stem;

Further, the surface of the valve stem and the surface of the valve core are hardened;

Further, the valve body is also provided with a boss for limiting the position of the valve stem;

Further, the packing gland is provided with screws for restricting the opening and closing of the valve.

The beneficial effects of the utility model:

1. By setting the pressure balance hole on the valve core, the inlet end of the valve is connected with the valve core, the valve core and the valve cavity to form a medium circulation channel, which ensures that the gas and the pressure of the entire pipeline form a whole, preventing the middle The cavity pressure is too high, causing the problem of dangerous gas or liquid leakage.

2. By setting the lip sealing ring at the sealing part of the valve stem and the connecting part of the valve body, when the pressure in the middle cavity rises abnormally, the two lips of the lip sealing ring will expand, and it will be close to the valve stem and the bonnet Wall, valve body and connecting body wall, the advantage of the lip seal ring is that the higher the pressure, the tighter the affixation, so it ensures that there is no leakage at the two places, and the two places are equipped with packing groups and metal wound gaskets, not only It can realize the secondary sealing and also play the function of safety and fire prevention.

Description of drawings

Fig. 1 is the utility model schematic diagram;

Fig. 2 is a schematic diagram of part A in Fig. 1;

Fig. 3 is a schematic diagram of part B in Fig. 1;

Figure 4 is a schematic diagram of the valve core.

Figure 1: 1. Valve body; 2. Connecting body; 3. Valve stem; 4. Valve core; 5. Seat sealing ring; 6. Spring; 7. Bonnet; 8. Packing gland; 9. Handle; 10 .Screw; 11. Nut; 12. Bolt; 13. Elastic washer; 14. Hexagon socket head cap screw; 15. Washer; 16. Nut; 17. Screw.

Figure 2: 18. Packing pad; 19. Lip seal ring one; 20. Packing group.

Figure 3: 21. Lip seal ring 2; 22. Metal winding pad 1; 23. Metal winding pad 2; 24. Sliding bearing; 25. Thrust washer; 26. Electrostatic spring; 27. Steel ball.

Figure 4: 28. Pressure equalization hole.

detailed description

The utility model is described now in conjunction with accompanying drawing:

As shown in Figure 1, Figure 2, and Figure 3, a low-temperature ball valve includes a valve body 1, a connecting body 2, a valve stem 3, a valve core 4, a valve cover 7, a packing gland 8, and a handle 9. The valve body 1 is fixedly connected with connecting body 2 through screw rod 10 and nut 11. There is spring 6 at the bottom of the valve seat at the inlet end of valve body 1. When fixing, install lip seal ring 2 21 and metal wound gasket 1 22. In addition to the lip seal ring installation groove and the metal wound gasket installation groove, there is also a boss used to limit the position of the valve stem 3, and the valve body 1 valve seat is set There is a valve seat sealing ring 5, a spring 6 is installed under the valve seat sealing ring 5, the valve core 4 is placed on the valve seat sealing ring 5, a through hole connected to the inside of the valve core is opened on the side of the valve core 4 as a pressure balance hole 28, The upper part of the valve core 4 has a groove, the cross section of the lower end of the valve stem 3 is square, the lower end of the valve stem 3 is embedded in the upper groove of the valve core 4 and connected with the valve core 4, the valve stem 3 is sleeved with a sliding bearing 24, and the upper part of the valve stem 3 is set There is a thrust washer 25, and the valve cover 7 passes through the valve stem 3 and is fixed to the valve body 1 with bolts 12 and elastic gaskets 13. An electrostatic spring 26 and a steel ball 27 are arranged between the valve stem 3 and the valve cover 7, and the valve cover 7 and the valve body 1 are provided with a metal wound gasket 2 23, a lip seal ring 1 19 is installed at the stuffing box of the bonnet 7, and the stuffing box of the bonnet 7 also includes a packing group 20, a packing pad 18, and a packing pad 18 is set On the lip seal ring 19, the packing group 20 is set on the packing pad 18, the packing gland 8 is installed on the top of the valve cover 7, the packing gland 8 is compressed and fixed with the hexagon socket head screw 14, and the handle is installed on the top of the valve stem 3 9. Compress and fix with nut 16 and washer 15; the surfaces of valve core 4 and valve stem 3 are hardened.

As shown in Figure 1, the direction of the arrow on the figure is the normal flow direction of the medium, and the medium flows from left to right. When the valve body flow channel, the ball flow channel and the connection body flow channel are fully opened, a fully open medium channel is formed. When fully closed, since the valve core 4 is provided with a pressure balance hole 28, the inlet end and the middle cavity of the valve body are integrated through the pressure balance hole 28 to form a medium circulation, which ensures that the gas and the gas pressure of the entire pipeline form a whole. Prevent the pressure in the middle cavity from being too high and ensure the safety of the valve. At the same time, the valve seat seal ring 5 at the inlet end pushes the valve core 4 to the valve seat seal ring 5 at the outlet end under the joint action of the medium pressure at the inlet end and the spring 6 to realize The outlet of the valve seat is sealed. This design increases the sealing specific pressure of the valve seat at the outlet end, greatly improves the sealing performance of the outlet end of the valve, and achieves zero leakage.

As shown in Figure 2: the medium in the middle cavity acts on the lip seal ring one 19 through the gap between the valve stem 3 and the valve cover 7, and when the pressure in the middle cavity rises, it will promote the two lips seal ring one 19 The lips expand outward under the action of the medium pressure, and the two expanded lips are close to the valve stem 3 and the valve cover 7, forming a first-level seal between the valve stem 3 and the valve cover 7, and at the same time on the upper part of the lip seal ring 19 A packing pad 18 and a packing group 20 are provided, and the screw 17 is pressed to the packing gland 8 to act on the packing group 20, and the packing group 20 forms a second-level seal under the upward action of the medium and the downward action of the packing gland 8 , The valve stem 3 and the valve cover 7 are double-sealed to make the seal more reliable and greatly reduce the leakage between the valve stem and the valve cover. The packing group 20 not only plays the role of secondary sealing but also has the function of safety and fire prevention.

As shown in Figure 3: the medium in the middle cavity acts on the lip seal 21 through the gap between the valve body 1 and the connecting body 2. When the pressure in the middle cavity rises, it will promote the two lips of the lip seal Under the action of the medium pressure, it expands outward, and the two expanded lips are close to the two walls of the valve body 1 and the connecting body 2, forming a primary seal between the valve body 1 and the connecting body 2, and at the same time in the ring groove of the valve body 1 A metal wound gasket 22 is provided, and the valve body 1 and the connecting body 2 are pressed by the screw rod 10 and the nut 11. The pressing force promotes the deformation of the metal wound gasket 1 22 to form a secondary seal. Under the action of the seal, the seal is more reliable, and the phenomenon of leakage between the valve body and the connecting body is greatly reduced. At the same time, the metal wound gasket-22 not only plays the role of secondary sealing, but also has the function of safety and fire prevention.

Claims (6)

1. a kind of cryogenic ball valve, including valve body, connector, valve rod, valve element, bonnet, gland, handle, it is characterised in that：Institute Valve body is stated with connector to be connected, the seat bottom portion at valve body import end be provided with spring, valve body provided with lip-type packing mounting groove and Metal wound gasket mounting groove, valve body inner seat is provided with below valve seat insert, valve seat insert and is provided with spring, and valve element is arranged at On valve seat insert, valve element side is provided with one and is communicated to the through hole of valve core inside as pressure compensation opening, and valve rod is connected with valve element, Stem exterior is arranged sliding bearing, and valve rod top is provided with thrust washer, and bonnet is fixed with valve body, provided with gold between bonnet and valve body Belong to wound gasket, be provided with electrostatic spring and steel ball, bonnet stuffing-box and be provided with lip-type packing, bonnet between bonnet and valve rod Side is provided with follower.

2. a kind of cryogenic ball valve as described in the appended claim 1, it is characterised in that：Also include filler group at the bonnet stuffing-box, In Packing seat, Packing seat setting and lip-type packing, filler group is arranged on Packing seat.

3. a kind of cryogenic ball valve as described in the appended claim 1, it is characterised in that：The valve element portion is provided with groove, is used for and valve rod It is fixed.

4. a kind of cryogenic ball valve as described in the appended claim 1, it is characterised in that：The stem surface is with spool face through overcure Processing.

5. a kind of cryogenic ball valve as described in the appended claim 1, it is characterised in that：The valve body, which is additionally provided with a boss, to be used to limit valve Bar position.

6. a kind of cryogenic ball valve as described in the appended claim 1, it is characterised in that：The gland is provided with screw, for limiting Valve switch processed.