CN105587884B - Low temperature ejection escape valve - Google Patents

Abstract

The application discloses a low-temperature emergency release valve, which includes a valve body, a ball, a valve cover, a valve stem, a packing gland, packing, a link disc, and a support shaft; the ball rotates on the valve stem and the support shaft The shaft is installed in the valve cavity of the valve body, the valve stem passes through the top of the valve body and is fixed on the ball, the support shaft is fixed on the bottom of the valve body, the valve cover is sleeved outside the valve stem and fixed on the valve body, The packing is fixed between the valve stem and the valve cover by the packing gland, and the link disc is fixed on an opening side of the valve body. The spherical surface seal of the new low-temperature emergency release valve adopts a spring energy storage ring, which effectively compensates for the shrinkage of the ball at low temperature, and the valve switching torque is also greatly reduced. The selected electro-hydraulic push rod actuator is also correspondingly reduced, which not only meets the weight limit Requirements, but also reduce the cost, and at the same time, the valve clamping mechanism is set on the valve body, the rigidity of the valve body is high, and the safety can be high.

Description

Low temperature emergency release valve

technical field

The present application relates to a valve, in particular to a low-temperature emergency release valve.

Background technique

With the increasing demand for liquefied natural gas (LNG) in the energy market, LNG has become a high-quality clean fuel with the fastest growth rate in the world. In the domestic coastal areas, several LNG receiving stations have started construction and put into operation one after another. After the LNG tanker arrives at the special wharf of the LNG receiving terminal, it sends the LNG into the storage tank of the receiving terminal through the conveying arm, the unloading pipeline, and the on-board unloading pump. An emergency release device must be installed on the LNG low-temperature delivery arm. The LNG low-temperature emergency release device can automatically and quickly separate the delivery arm from the tanker in the event of an emergency (fire, typhoon or excessive drift, etc.) at the loading and unloading site. It plays an important role in ensuring personal safety and reducing accidents and losses. The emergency release device is composed of an emergency release valve and a hydraulic cylinder drive. When an emergency occurs, the emergency release device will automatically enter the working state, and the release device will send out a release signal. The hydraulic cylinder drives the push rod to close the cut-off valve first, and then push the clamping The locking lever of the mechanism opens the clamping mechanism to separate the two emergency release valves, so as to achieve the purpose of quickly separating the tanker from the conveying arm. After disengagement, the upper emergency disengagement valve is removed with the outer arm, and the lower emergency disengagement valve is taken away with the ship. Therefore, it is one of the key equipment for the emergency release device of the LNG cryogenic delivery arm, and is used in the field of low-temperature delivery of liquid oxygen, liquid nitrogen, liquid argon, and liquefied natural gas.

Existing low-temperature valves generally use PTFE or PCTFE sealing materials, and the shrinkage ratio of metal materials and non-metal materials in low-temperature media is very different, resulting in difficulty in sealing valves at low temperatures. Conventional sealing design, due to the decrease of elasticity of non-metallic materials at low temperature, increase of hardness, and large deformation, the specific pressure of the seal must be increased to meet the sealing requirements, resulting in the valve torque being much larger than that of normal temperature valves, and the volume and weight of the operating mechanism correspondingly increased. In addition, the low-temperature emergency release device is installed on the cantilever arm, and is operated by an electro-hydraulic push rod switch, which has restrictions on the weight and torque of the valve. Conventional low-temperature valves are designed with double valve seats, which cannot meet the requirements of low torque, high sealing, and light weight. Require. The valve clamping mechanism is arranged on the link disc device, and the link disc device not only bears the sealing force of the valve, but also bears the clamping force and the load bending moment of the valve, which will bring reliability and safety problems. Finally, the conventional sphere adopts a solid sphere, which has high rigidity and small deformation, and its weight is much larger than that of the hollow sphere structure. However, hollow balls are difficult to manufacture, have large shrinkage at low temperature, large deformation at low temperature, and difficult sealing. So more improvements are needed.

Contents of the invention

The object of the present invention is to provide a low temperature emergency release valve to overcome the deficiencies in the prior art.

To achieve the above object, the present invention provides the following technical solutions:

The invention discloses a low-temperature emergency release valve, which comprises a valve body, a ball, a valve cover, a valve stem, a packing gland, packing, a link disc and a support shaft; the ball is formed by the valve stem and the support shaft The rotating shaft is installed in the valve cavity of the valve body, the valve stem passes through the top of the valve body and is fixed to the ball, the support shaft is fixed at the bottom of the valve body, and the valve cover is sleeved on the outside of the valve stem and fixed on the valve body , the packing is fixed between the valve stem and the top of the valve cover by the packing gland, the link disc is fixed on an opening side of the valve body, a sealing seat is provided between the link disc and the surface of the sphere, and the sealing seat There is a seal between the surface of the ball and the ball;

Further, a spring and a first energy storage ring are arranged between the link disc and the sealing seat, the inner wall of the link disc is recessed inwardly to form a step, and the first energy storage ring is installed on the step superior;

Further, a second energy storage ring is provided between the link disc and the valve body, a step is provided on the link disc, and the second energy storage ring is installed on the step;

Further, the side of the link plate facing away from the sealing seat is recessed to form a first annular groove and a second groove, and the first graphene groove is respectively installed in the first groove and the second groove. Gasket and third accumulator ring.

Preferably, in the above-mentioned cryogenic emergency release valve, the ball has an axially connected flow channel.

Preferably, in the above-mentioned low-temperature emergency release valve, the valve cover adopts a neck extension structure, the upper part is provided with a stuffing box for filling the stuffing, the bottom of the stuffing box is provided with a raised step, and the bottom of the stuffing box is provided with a stuffing box in turn. Gasket and fourth accumulator ring;

Further, a fifth energy storage ring and a second graphene gasket are provided between the valve cover and the valve body, and a through hole is provided on the top of the valve body, and a ring-shaped third recess is formed in the through hole inwardly. groove and the fourth groove, the fifth energy storage ring and the second graphene gasket are installed in the third groove and the fourth groove respectively.

Preferably, in the above-mentioned low-temperature emergency release valve, the easily broken part of the valve stem is arranged at a visible part above the stuffing box of the valve cover, a circular groove is provided at the bottom of the valve cover, and the lower section of the valve stem A bushing is provided, and the bushing is fixed in the circular groove.

Preferably, in the above low-temperature emergency release valve, the support shaft is composed of a stepped shaft and a shaft seat, the stepped shaft is fixed at the center of the shaft seat, and a third graphene gasket and a third graphene gasket are arranged between the support shaft and the valve body. The sixth energy storage ring, the through hole is recessed to form a fifth annular groove and a sixth groove, and the third graphene gasket and the sixth energy storage ring are respectively installed in the fifth groove and in the sixth groove;

Further, a circular hole is opened at the bottom of the sphere, and a bushing is embedded in the circular hole, the shaft seat part of the support shaft is fixed on the valve seat, and the stepped shaft part of the support shaft passes through the bottom of the valve body The provided through hole is movably fixed in the bush, and an adjusting washer is provided between the support shaft and the sphere.

Preferably, in the above-mentioned low-temperature emergency release valve, the energy storage ring adopts a lip-type flexible energy storage sealing structure in which a polymer material sealing ring and an energy storage spring material are combined together.

Preferably, in the above low temperature emergency release valve, the valve body, the ball, the valve cover, the valve stem, the packing gland, the link disc and the support shaft can conduct electricity.

Compared with the prior art, the present invention has the advantages of:

1. The low temperature emergency release valve uses a spring energy storage ring to effectively compensate the shrinkage of the sealing material at low temperature;

2. The low-temperature emergency release valve adopts a single-seat fixed ball valve design, which reduces the valve switching torque, weight and cost;

3. The low-temperature emergency release valve uses a spring energy storage ring to effectively compensate the shrinkage of the ball at low temperature, and the valve switching torque is also greatly reduced. The selected electro-hydraulic push rod actuator is also correspondingly reduced, which not only meets the weight limit requirements, reduced costs;

4. The clamping mechanism of the low-temperature emergency release valve is set on the valve body, which has high rigidity and high safety;

5. The low-temperature emergency release valve conducts electricity between components to avoid static electricity accumulation.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is a schematic diagram of a low-temperature fixed ball valve in a low-temperature emergency release valve in a specific embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1, the low-temperature emergency release valve includes valve body 1, ball 2, valve cover 3, valve stem 4, packing gland 5, packing 6, link disc 7 and support shaft 8; ball 1 is connected with valve stem 4 and The support shaft 8 is a rotating shaft installed in the valve cavity of the valve body 1, the valve stem 4 passes through the top of the valve body 1 and is fixed on the ball 2, the support shaft 8 is fixed on the bottom of the valve body 1, and the valve cover 301 is set outside the valve stem 4 and fixed On the valve body 1, the packing 601 is fixed between the valve stem 4 and the top of the valve cover 3 by the packing gland 5, the link disc 7 is fixed on the opening side of the valve body 1, and a sealing seat is provided between the link disc 7 and the surface of the sphere 2 702, a seal 703 is provided between the sealing seat 702 and the surface of the sphere 2;

Further, a spring 704 and a first energy storage ring 705 are arranged between the link disc 7 and the sealing seat 702, the inner wall of the link disc 7 is recessed inwardly to form a step, and the first energy storage ring 705 is installed on the step;

Further, a second energy storage ring 709 is provided between the link disc 7 and the valve body 1, a step is provided on the link disc 7, and the second energy storage ring 709 is installed on the step;

Further, the side of the link disk 7 facing away from the sealing seat 702 is concavely formed with a first annular groove 7012 and a second groove 7013, and the first graphene groove 7012 and the second groove 7013 are installed respectively. Washer 708 and third accumulator ring 706 .

The sphere 2 has an axially connected flow channel, and the surface is hardened to reduce the amount of deformation and the erosion damage of the spherical surface by the medium.

The valve cover 3 adopts a neck extension structure, and the upper part is provided with a stuffing box 305 for filling the stuffing 601. The bottom of the stuffing box 305 is provided with a raised step 304, and the bottom of the stuffing is provided with a stuffing gasket 602 and a fourth energy storage ring 603 in sequence. It adopts the combination structure of elastic sealing ring and flexible graphite, which has low maintenance design, small friction coefficient and good wear resistance, and has material toughness and ductility under the condition of -196°C, which meets the low leakage requirements stipulated in the liquefied natural gas valve test. Requirements: The bonnet 3 is designed as a neck extension structure for cold preservation, the neck extension structure is integrally forged with the bonnet, and the extension length meets the steam space requirements, so that the working temperature of the packing 601 is kept within its allowable operating temperature range . The wall thickness of the extended part of the neck of the bonnet 3 considers the operating pressure of the valve, the operating force of the actuator, the self-weight of the actuator and the comprehensive stress generated under special installation conditions. The radial clearance between the valve stem 4 and the extended bonnet 3 is minimized to reduce heat convective losses.

Further, a fifth energy storage ring 303 and a second graphene gasket 302 are provided between the valve cover 3 and the valve body 1, and a through hole is provided on the top of the valve body 1, and a third ring-shaped groove is formed in the through hole inwardly. 102 and the fourth groove 101, the fifth energy storage ring 303 and the second graphene gasket 302 are installed in the third groove 102 and the fourth groove 101 respectively.

The easily broken part of the valve stem 4 is arranged on the visible part above the stuffing box 305 of the valve cover. Groove; Stem 4 adopts anti-blowout design, the integral bushing is fixed, and double packing seals have the characteristics of flexible stem rotation, reliable sealing, no frosting on the packing, and maintenance-free.

The support shaft 8 is composed of a stepped shaft 801 and a shaft seat 802. The stepped shaft 801 is fixed at the center of the shaft seat 802. A third graphene gasket 804 and a sixth energy storage ring 803 are arranged between the support shaft 8 and the valve body 1. The valve The bottom of the body 1 is provided with a through hole, and the through hole is recessed inward to form an annular fifth groove 103 and a sixth groove 104, and the third graphene gasket 804 and the sixth energy storage ring 803 are respectively installed in the fifth groove 103 and the sixth groove 104;

Further, a round hole 203 is opened at the bottom of the ball 2, and a bushing 204 is embedded in the round hole 203. The shaft seat 802 of the supporting shaft is fixed on the valve body 1, and the stepped shaft 801 moves through the through hole provided at the bottom of the valve body 1. Fixed in the bushing 204 , an adjusting washer 805 is provided between the support shaft 8 and the sphere 2 .

A sealing ring 707 and a graphite gasket 709 are provided on the outer side of the link disk device 7 , and a sealing ring 7012 is provided on the outlet side of the valve body 1 .

Furthermore, all the energy storage rings mentioned above adopt a lip-type flexible energy storage sealing structure that combines polymer material sealing rings and energy storage spring materials, carefully designed a two-way sealing structure, and fully paid attention to the use of sealing materials and auxiliary metal elastic materials It has the characteristics of elasticity and energy storage. At the same time, the first contact between the energy storage ring and the sphere 2 creates conditions for the energy storage of the sealing seat 702. When the pressure, temperature changes or even wears out, the first contact between the energy storage ring and the sphere 2 Some parts can be compensated for bending or deflection, relying on elastic surface compression deformation to achieve sealing, and compensating for changes in temperature and pressure, greatly improving sealing performance, especially low-pressure sealing, prolonging service life. The geometric shape of the curved surface is complex, and the dimensional accuracy is very high, so special technological means must be used to meet the design requirements. In order to ensure the reliability of the seal, a spring 704 is provided on the back of the seal seat 702, which can automatically adjust the specific pressure of the seal with the change of the medium pressure, reducing the operating torque of the valve.

The valve body, ball, valve cover, valve stem, packing gland, link disc and support shaft can conduct electricity to avoid static electricity accumulation.

The low temperature emergency release valve adopts the spring energy storage ring to effectively compensate the shrinkage of the sealing material at low temperature; the single seat fixed ball valve design reduces the valve switching torque, reduces the weight, and reduces the cost; the spring energy storage ring is effective The shrinkage of the sphere at low temperature is fully compensated, the valve switching torque is also greatly reduced, and the selected electro-hydraulic push rod actuator is also correspondingly reduced, which not only meets the weight limit requirements, but also reduces the cost; at the same time, the clamping mechanism is set at On the valve body, the rigidity of the valve body is high, and the safety can be high; finally, the components of the low-temperature emergency release valve conduct electricity to avoid static electricity accumulation.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above description is only the specific implementation of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present application, some improvements and modifications can also be made. It should be regarded as the protection scope of this application.

Claims (5)

1. a kind of low temperature ejection escape valve, which is characterized in that including a valve body, sphere, valve deck, valve rod, gland, filler, Link disk and support shaft；The sphere is installed on as rotation axis in the valve body valve chamber using the valve rod and the support shaft, institute It states valve rod and is fixed on sphere through body top, the support shaft is fixed on body base, and it is outer and solid that the valve deck is sleeved on valve rod Due on valve body, the filler is fixed on by the gland between valve rod and valve deck top, and the link disk is fixed on valve body One open side is equipped with seal receptacle between the link disk and spherome surface, sealing is equipped between the seal receptacle and spherome surface Part,

Spring and the first accumulation of energy circle are equipped between the link disk and seal receptacle, the inner wall of the link disk sets to the concave to form platform Rank portion, the first accumulation of energy circle are installed in the stage portion；

The second accumulation of energy circle is equipped between the link disk and valve body, the link disk is equipped with step, the second accumulation of energy circle peace Loaded on the step；

Recessed the first groove and the second groove for being formed with annular in one side that the link disk deviates from the seal receptacle, described first The first graphene washer and the 3rd accumulation of energy circle are separately installed in groove and the second groove；

The valve deck uses neck extension structure, and top is equipped with stuffing-box for filling the filler, and the filler is using elasticity Sealing ring and soft graphite combining structure, stuffing-box bottom are equipped with raised step, are equipped with filler washer and the below filler successively Four accumulation of energy circles；The 5th accumulation of energy circle and the second graphene washer are equipped between the valve deck and valve body, the body top is equipped with through hole, The through hole, which sets to the concave, is formed with the 3rd groove and the 4th groove of annular, the 5th accumulation of energy circle and the second graphene washer It is respectively arranged in the 3rd groove and the 4th groove；

The valve rod frangible portions are arranged on visible the position more than stuffing-box of the valve deck, and the valve deck bottom is equipped with circle Groove, the valve rod hypomere are equipped with bushing, and the bushing is fixed on the circular groove.

2. low temperature ejection escape valve according to claim 1, it is characterised in that：The sphere has the stream axially communicated Road.

3. low temperature ejection escape valve according to claim 1, which is characterized in that the support shaft is by multi-diameter shaft and axle bed group Into, the multi-diameter shaft is fixed on axle bed center, and the 3rd graphene washer and the 6th accumulation of energy circle are equipped between the support shaft and valve body, The through hole, which sets to the concave, is formed with the 5th groove and the 6th groove of annular, the 3rd graphene washer and the 6th accumulation of energy circle It is respectively arranged in the 5th groove and the 6th groove；

The sphere bottom is provided with circular hole, and the circular hole is embedded with bushing, and the axle seat portion of the support shaft is fixed on valve seat, institute The multi-diameter shaft for stating support shaft partially passes through the through hole activity that the body base is equipped with and is fixed in the bushing, the support shaft Adjusting washer (disk) is equipped between the sphere.

4. low temperature ejection escape valve according to any one of claims 1 to 3, which is characterized in that the accumulation of energy circle uses high score Sub- material sealing ring and the combined lip type flexibility accumulation of energy sealing structure of energy-storaging spring material.

5. low temperature ejection escape valve according to claim 1, which is characterized in that the valve body, sphere, valve rod, are filled out valve deck Expect that gland, link disk and support between centers can be conductive.