CN113418033B

CN113418033B - Low temperature check valve and welding frock

Info

Publication number: CN113418033B
Application number: CN202110823535.9A
Authority: CN
Inventors: 王青青
Original assignee: Beijing Zhongke Fu Hai Low Temperature Technology Co ltd
Current assignee: Beijing Zhongke Fu Hai Low Temperature Technology Co ltd
Priority date: 2021-07-21
Filing date: 2021-07-21
Publication date: 2022-10-28
Anticipated expiration: 2041-07-21
Also published as: CN113418033A

Abstract

The invention is suitable for the field of check valves, and discloses a low-temperature check valve and a welding tool for welding the low-temperature check valve and a connecting pipe, wherein the low-temperature check valve comprises a valve body, a valve cover assembled in the valve body, a valve clack assembled in the valve body, a sealing element assembled at one end of the valve clack, and an elastic element assembled at the other end of the valve clack, an inlet is formed in the valve body, an outlet is formed in the valve cover, the sealing element is abutted against the valve body, the elastic element is elastically compressed between the valve clack and the valve cover, an overflowing hole for communicating the inlet and the outlet is formed in the valve clack, a lifting part is further arranged in the valve clack, the valve clack is driven to compress the elastic element and axially move to separate the sealing element from the valve body when tensile force is applied to the lifting part, and then the low-temperature resistant sealing element on the valve clack is separated from the valve body and then welded with the connecting pipe, therefore, heat generated when the valve body is welded with the connecting pipe, the low-temperature resistant sealing element is not easily conducted to the low-temperature resistant sealing element, and the low-temperature sealing element cannot be damaged.

Description

Low temperature check valve and welding frock

Technical Field

The invention relates to the technical field of check valves, in particular to a low-temperature check valve and a welding tool.

Background

Check valves, also known as check valves, are often used in industrial pipelines to prevent media from flowing back and mixing. Common check valves include horizontal check valves, butterfly check valves, lift check valves, spring check valves, etc., wherein the spring check valves can be installed in horizontal and vertical directions without strict installation directions, and thus are widely used in industrial pipelines.

Under low temperature conditions, the sealing mode of the threads or the flanges is easy to leak because of large shrinkage deformation of the valve body or the sealing material. Especially when the fluid medium is hydrogen, leakage through the gap is likely to occur because hydrogen molecules are minimal. The existing check valve is mostly in a threaded or flange connection mode, has poor sealing effect at low temperature and is particularly not suitable for media such as liquid hydrogen and the like. The welding is lower for screw thread or flange joint, and the leak rate is lower, and does not receive low temperature to influence, but, uses low temperature resistant materials such as polytetrafluoroethylene, polymer polyethylene in the seal gasket of valve clack often, and this kind of gasket itself is high temperature resistant, damages easily during the welding. This also results in existing cryogenic valves using less welding processes.

Disclosure of Invention

The first object of the present invention is to provide a low temperature check valve, which can separate a low temperature resistant sealing member on a valve flap from a valve body and then weld the valve flap, so that heat generated when the valve body is welded to a connection pipe is not easily transferred to the low temperature resistant sealing member, and the low temperature resistant sealing member is not damaged.

In order to achieve the purpose, the invention provides the following scheme:

the utility model provides a low temperature check valve, is in including valve body, assembly valve gap, assembly in the valve body are in valve clack, assembly in the valve body are in the sealing member of the one end of valve clack and assembly are in the elastic component of the valve clack other end, be provided with the entry on the valve body, be provided with the export on the valve gap, the sealing member with the valve body butt, elastic component elastic compression is in the valve clack with between the valve gap, be provided with the intercommunication on the valve clack the entry with the discharge orifice of export, still be provided with in the valve clack and carry the portion of drawing, it drives when being exerted pulling force to carry the portion of drawing the valve clack compression elastic component and axial motion so that the sealing member with the valve body separates.

Preferably, the pull-up portion is a crossbar disposed within the valve flap.

Preferably, the valve flap comprises a first step portion and a second step portion, the outer diameter of the first step portion is smaller than that of the second step portion, the inner diameter of the first step portion is smaller than that of the second step portion, the overflowing hole is formed in the first step portion, the sealing member is assembled on the first step portion, the lifting portion is arranged in the first step portion, and the elastic member is assembled in the second step portion.

Preferably, one end, facing the inlet, of the first step portion is provided with a sealing groove for mounting the sealing element, and a groove wall of the sealing groove is internally provided with a limiting protrusion.

Preferably, one end of the first step portion facing the inlet is provided with a conical flow guide portion.

Preferably, one end of the valve body, which is provided with the inlet, is provided with a flow cavity, the flow cavity is a cylindrical cavity, the edge of the flow cavity is provided with a chamfer, and the diameter of the flow cavity is larger than that of the inlet.

Preferably, a position where the valve body contacts the seal member is provided with a seal projection for abutting against the seal member.

Preferably, the low temperature resistant sealing element is a sealing gasket made of polytetrafluoroethylene materials.

The second object of the present invention is to provide a welding tool for sealing and welding the low temperature check valve and the connection pipe, the welding tool comprising an auxiliary tool and a welding device, the welding device being used for performing welding operation on the valve body and the connection pipe, the auxiliary tool comprising an auxiliary hook, wherein the end of the auxiliary hook is arranged in a hook shape and is adapted to the lifting part to apply a pulling force to the lifting part so as to separate the sealing member from the valve body.

Preferably, the auxiliary tool further comprises a positioning pin for fixing the auxiliary hook, and the auxiliary hook is provided with a positioning hole matched with the positioning pin.

According to the low-temperature check valve provided by the invention, the lifting part is arranged in the valve clack, when the low-temperature check valve and the connecting pipe are welded, the valve clack can be driven to move towards the outlet direction by applying pulling force to the lifting part, so that the low-temperature-resistant sealing element on the valve clack is separated from the valve body and then welded, therefore, heat generated when the valve body is welded with the connecting pipe is not easily conducted to the low-temperature-resistant sealing element, and the low-temperature-resistant sealing element cannot be damaged.

According to the welding tool, when the low-temperature check valve and the connecting pipe are welded through the auxiliary tool, the low-temperature-resistant sealing element on the valve clack can be separated from the valve body by applying pulling force to the valve clack, and then the valve body and the connecting pipe are welded through the welding equipment, so that heat generated when the valve body and the connecting pipe are welded is not easily transmitted to the low-temperature-resistant sealing element, and the low-temperature-resistant sealing element cannot be damaged.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the structures shown in the drawings without creative efforts.

FIG. 1 is an exploded view of a cryogenic check valve provided by an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the low temperature check valve shown in FIG. 1, with the valve body sealed to the valve flap;

FIG. 3 is a cross-sectional view of the low temperature check valve shown in FIG. 1, with the media flowing into the valve body;

FIG. 4 is a cross-sectional view of a valve body provided by an embodiment of the present invention;

FIG. 5 is a schematic diagram of a valve flap according to an embodiment of the present invention;

FIG. 6 is a cross-sectional view of the valve flap shown in FIG. 5;

FIG. 7 is an enlarged view of A in FIG. 6;

FIG. 8 is a schematic view of a combination of an auxiliary tool, a cryogenic check valve and a nozzle provided by an embodiment of the present invention;

fig. 9 is a schematic structural diagram of an auxiliary hook provided in an embodiment of the present invention.

Description of the drawing reference numbers:

1. a low temperature check valve; 10. a valve body; 11. an inlet; 12. a flow chamber; 13. sealing the protrusion; 14. a step; 20. a valve cover; 21. an outlet; 30. a valve clack; 31. a pulling section; 32. an overflowing hole; 33. a first step portion; 331. a sealing groove; 332. a limiting bulge; 333. a conical flow guide part; 34. a second step section; 40. a seal member; 50. an elastic member;

2. taking over the pipe;

3. an auxiliary tool; 301. an auxiliary hook; 3011. positioning holes; 302. and a positioning pin.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that all directional indicators (such as up, down, left, right, front, back \8230;) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the motion situation, etc. in a specific posture (as shown in the attached drawings), and if the specific posture is changed, the directional indicator is changed accordingly.

It will also be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present.

In addition, the descriptions related to "first", "second", etc. in the present invention are for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between the embodiments may be combined with each other, but must be based on the realization of the technical solutions by a person skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

As shown in fig. 1 to 7, a low temperature check valve 1 according to an embodiment of the present invention is applied to an industrial pipeline to prevent media from flowing back and mixing, when the low temperature check valve 1 is applied to an industrial pipeline, the low temperature check valve 1 is often connected to the industrial pipeline in a sealing manner, in order to improve the sealing performance between the low temperature check valve 1 and the industrial pipeline at a low temperature, the low temperature check valve 1 is welded to the industrial pipeline, and in order to avoid the performance of a sealing member 40 of the low temperature check valve 1 from being affected when the low temperature check valve 1 is welded to the industrial pipeline, a lifting portion 31 is provided in the valve flap 30, so that when the low temperature check valve 1 is welded to a connection pipe 2, the lifting portion 31 can pull the valve flap 30 toward an outlet 21, thereby separating the low temperature resistant sealing member 40 on the valve flap 30 from the valve body 10, and thus, heat generated when the low temperature check valve 1 is welded to the connection pipe 2 is not easily conducted to the low temperature resistant sealing member 40, and the low temperature resistant sealing member 40 is not damaged.

Referring to fig. 1 to 7, a low temperature check valve 1 according to an embodiment of the present invention includes a valve body 10, a valve cover 20 assembled in the valve body 10, a valve flap 30 assembled in the valve body 10, a sealing member 40 assembled at one end of the valve flap 30, and an elastic member 50 assembled at the other end of the valve flap 30, the valve body 10 is provided with an inlet 11, the valve cover 20 is provided with an outlet 21, the sealing member 40 abuts against the valve body 10, the elastic member 50 is elastically compressed between the valve flap 30 and the valve cover 20, the valve flap 30 is provided with a through-flow hole 32 so that the inlet 11 and the outlet 21 are communicated through the through-flow hole 32 when the valve flap 30 moves toward the outlet 21, the valve flap 30 is further provided with a pulling portion 31, the pulling portion 31 is applied with a tensile force to drive the valve flap 30 to compress the elastic member 50 and move axially to separate the sealing member 40 from the valve body 10, and when the low temperature check valve 1 and the adapter 2 are welded, the low temperature sealing member 40 on the valve flap 30 is separated from the valve body 10, so that heat generated when the check valve 1 and the adapter 2 are welded, the check valve 40 is not easily conducted to the adapter 2, and the sealing member 40 is not damaged.

It can be understood that the lifting portion 31 can be a cross bar disposed in the valve flap 30, the cross bar can be a long cross bar or a short cross bar, if the cross bar is a short cross bar, a hook hole can be disposed at a free end of the short cross bar, or the free end of the short cross bar can be set to be hook-shaped, as long as during welding, an operator can extend the auxiliary tool 3 into the valve flap 30 from the outlet 21 to hook the lifting portion 31 and pull the valve flap 30 to move toward the outlet 21.

Further, the auxiliary tool 3 includes an auxiliary hook 301, and the tip of the auxiliary hook 301 is provided in a hook shape and is fitted to the pulling part 31.

Furthermore, the auxiliary tool 3 further comprises a positioning pin 302, a plurality of positioning holes 3011 are formed in the auxiliary hook 301, and the auxiliary hook 301 is fixed on the welding platform through the matching of the positioning pin 302 and the positioning holes 3011, so that an operator is not required to apply a pulling force to the auxiliary hook 301 all the time during welding, and the valve flap 30 is prevented from being automatically reset by the operator due to hand loss.

Alternatively, the elastic member 50 may be a spring or an elastic pad.

The working principle of the low-temperature check valve 1 of the embodiment of the invention is as follows;

when the medium flows in, the pressure of the inlet 11 side is larger than that of the outlet 21 side, when the differential pressure acting force is larger than the elastic force of the spring, the valve clack 30 compresses the spring under the action of the differential pressure, the valve is opened, and the medium flows in; when the pressure difference is small, the pressure difference acting force is smaller than the elastic force of the elastic piece 50, the valve clack 30 compresses the valve body 10, and the sealing piece 40 is compressed between the valve clack 30 and the valve body 10, so that sealing is realized. When the pressure of the outlet 21 is larger than that of the inlet 11, the valve clack 30 presses the valve body 10 under the action of the pressure difference, and the non-return function is realized.

According to the low-temperature check valve 1, the lifting part 31 is arranged in the valve clack 30, when the low-temperature check valve 1 and the connecting pipe 2 are welded, the valve clack 30 can be driven to move towards the outlet 21 by applying pulling force to the lifting part 31, and the low-temperature-resistant sealing element 40 on the valve clack 30 is separated from the valve body 10 and then welded, so that heat generated when the valve body 10 and the connecting pipe 2 are welded is not easily conducted to the low-temperature-resistant sealing element 40, and the low-temperature-resistant sealing element 40 cannot be damaged.

Referring to fig. 2 and 3, the valve body 10 and the valve cover 20 are welded together to form a valve, and the valve body 10 and the valve cover 20 are hermetically connected by welding, so that the sealing performance of the valve body 10 and the valve cover 20 at a low temperature can be improved.

Referring to fig. 1-5, the valve body 10 has an inlet 11 at one end thereof, a flow chamber 12 is provided, and the medium flows into the flow chamber 12 from the inlet 11 and flows out of the outlet 21 through a flow hole 32 of the valve flap 30. The flow cavity 12 is a cylindrical cavity, the edge of the flow cavity is chamfered, the diameter of the flow cavity 12 is larger than that of the inlet 11, and the area of any flow section is not lower than that of the inlet 11 in the process of flowing media in the valve, so that the media can flow more smoothly, the flow resistance is smaller, and the pressure loss can be reduced.

Further, a sealing protrusion 13 is provided at a position where the valve body 10 contacts the sealing member 40, and when the valve flap 30 is sealed with the valve body 10, the sealing protrusion 13 abuts against the sealing member 40, which can further enhance the sealing performance.

Further, the inner side wall of the valve body 10 is convexly provided with a step 14 matched with the valve clack 30, so that the reciprocating motion of the valve clack 30 is guided, and the valve clack does not shake.

Referring to fig. 1 to 6, the valve flap 30 is a stepped cylindrical structure with a hollow interior, and includes a first step portion 33 and a second step portion 34, an outer diameter of the first step portion 33 is smaller than an outer diameter of the second step portion 34, an inner diameter of the first step portion 33 is smaller than an inner diameter of the second step portion 34, the overflowing hole 32 is disposed on the first step portion 33, the sealing member 40 is disposed on the first step portion 33, the pulling portion 31 is disposed in the first step portion 33, the elastic member 50 is disposed in the second step portion 34, the valve flap 30 is disposed in a stepped cylindrical structure, which is beneficial for medium flowing, and at the same time, the elastic member 50 is convenient to assemble, and the pulling portion 31 is disposed in the first step portion 33, the elastic member 50 is disposed in the second step portion 34, and the arrangement of the pulling portion 31 does not affect the axial movement of the valve flap 30.

Further, one end of the first step portion 33 facing the inlet 11 is provided with a sealing groove 331 for installing the sealing element 40, and a groove wall of the sealing groove 331 is provided with a limiting protrusion 332 for limiting the sealing element 40 to be separated, so that the sealing element 40 needs to be precooled during installation to be contracted, and a tool is used for knocking the sealing element 40 to enable the sealing element 40 to enter the sealing groove 331.

Furthermore, a tapered guiding portion 333 is disposed at an end of the first step portion 33 facing the inlet 11, the sealing groove 331 is disposed at an outer peripheral side of the tapered guiding portion 333, when the medium flows, a pressure at the inlet 11 side is greater than a pressure at the outlet 21 side, and a differential pressure acting force is greater than an elastic force of the spring, the valve flap 30 compresses the spring under the action of the differential pressure, the valve opens, and the medium flows into the valve cavity along the tapered guiding portion 333, so that the flow resistance of the medium can be reduced.

Referring to fig. 1 to 3, the low temperature resistant sealing element 40 is a sealing gasket made of low temperature resistant materials such as Polytetrafluoroethylene (PTFE) and has a good sealing effect, and meanwhile, the welding auxiliary tool 3 is used to assist the welding of the valve, so that the sealing gasket is not easily affected by the welding heat.

Referring to fig. 1 to 9, an embodiment of the present invention further provides a welding tool for hermetically welding the low temperature check valve 1 and the connection pipe 2, the welding tool includes an auxiliary tool 3 and a welding device, the auxiliary tool 3 is used for applying a pulling force to the pulling portion 31 of the low temperature check valve 1 to separate the sealing member 40 of the low temperature check valve 1 from the valve body 10, and the welding device is used for performing a welding operation on the valve body 10 and the connection pipe 2. The auxiliary tool 3 includes an auxiliary hook 301, and the tip of the auxiliary hook 301 is provided in a hook shape and is fitted to the pulling part 31.

Further, the auxiliary tool 3 further comprises a positioning pin 302, the positioning hole 3011 is formed in the auxiliary hook 301, the auxiliary hook 301 is fixed on the welding platform through the matching of the positioning pin 302 and the positioning hole 3011, and therefore an operator is not required to apply pulling force to the auxiliary hook 301 all the time during welding, and the valve flap 30 is prevented from being automatically reset due to the fact that the operator loses hands.

Furthermore, positioning holes 3011 are spaced at intervals, and positioning pins 302 are inserted into appropriate positioning holes 3011 as required.

It will be appreciated that, instead of applying a pulling force to the pulling portion 31 by the auxiliary hook 301, the pulling portion 31 may be made ferrous, the auxiliary hook 301 may be made magnetic, and the sealing member 40 and the valve body 10 may be separated by pulling the valve flap 30 toward the outlet 21 by the principle of magnetic attraction.

According to the welding tool provided by the embodiment of the invention, when the low-temperature check valve 1 and the connecting pipe 2 are welded by arranging the auxiliary tool 3, the low-temperature-resistant sealing element 40 on the valve clack 30 can be separated from the valve body 10 by applying a pulling force to the valve clack 30, and then the valve body 10 and the connecting pipe 2 are welded by the welding equipment, so that heat generated when the valve body 10 and the connecting pipe 2 are welded is not easily transmitted to the low-temperature-resistant sealing element 40, and the low-temperature-resistant sealing element 40 cannot be damaged.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A low-temperature check valve is characterized by comprising a valve body, a valve cover assembled in the valve body, a valve clack assembled in the valve body, a sealing element assembled at one end of the valve clack, and an elastic element assembled at the other end of the valve clack, wherein an inlet is formed in the valve body, an outlet is formed in the valve cover, the sealing element is abutted against the valve body, the elastic element is elastically compressed between the valve clack and the valve cover, an overflowing hole for communicating the inlet and the outlet is formed in the valve clack, and a lifting part is further arranged in the valve clack and drives the valve clack to compress the elastic element and axially move to separate the sealing element from the valve body when tensile force is applied to the lifting part;

the lifting part is a cross rod arranged in the valve clack;

the valve flap comprises a first step part and a second step part, the outer diameter of the first step part is smaller than that of the second step part, the inner diameter of the first step part is smaller than that of the second step part, the overflowing hole is arranged on the first step part, the sealing element is assembled on the first step part, the lifting part is arranged in the first step part, and the elastic element is assembled in the second step part;

the first step portion is towards the one end of entry is provided with and is used for installing the seal groove of sealing member, be provided with spacing arch in the cell wall of seal groove.

2. The cryogenic check valve of claim 1, wherein an end of the first step portion facing the inlet is provided with a tapered flow guide.

3. The cryogenic check valve of claim 1, wherein the end of the valve body at which the inlet is located is provided with a flow chamber, the flow chamber is a cylindrical cavity, and the edge of the flow chamber is provided with a chamfer, the diameter of the flow chamber being greater than the diameter of the inlet.

4. The cryogenic check valve of claim 1, wherein a location where the valve body contacts the seal is provided with a sealing protrusion for abutting the seal.

5. The cryogenic check valve of claim 1, wherein the seal is a gasket made of a polytetrafluoroethylene material.