Check valve for liquefied natural gas

Abstract

The utility model discloses a check valve for liquefied natural gas, which relates to the field of check valves and comprises a valve body, a lower connecting flange is mounted at the top of the valve body, an upper connecting flange is fixedly mounted on the lower connecting flange through a bolt and a nut, a sealing piece is mounted on the butt joint surface of the lower connecting flange and the upper connecting flange, and a sealing ring is mounted on the sealing piece. A sleeve protruding downwards is integrally formed at the bottom end of the upper connecting flange, the top of the sleeve is of an open structure, a replaceable elastic mechanism extending to an inner cavity of the sleeve is installed at the top of the upper connecting flange, and sealing mechanisms are distributed and installed between the periphery of the sleeve and the inner wall of the valve body. Through the arrangement of the replaceable elastic mechanism, the spring can be independently replaced under the condition that the valve body does not need to be disassembled, and the condition of natural gas leakage cannot occur in the replacement process, so that the spring replacement efficiency is higher, and the replacement safety is better.

Description

TECHNICAL FIELD

[0001] The utility model relates to check valve field, concretely is a check valve for liquefied natural gas. BACKGROUND

[0002] Check valve includes swing check valve and lift check valve, and the valve plate (also called: sealing plug) of lift check valve moves upward when being subjected to pressure, resets downward when pressure is small, and gas backflow is avoided.

[0003] In prior art, reset power of valve plate is from spring installed at top end of valve plate, and spring appears metal fatigue phenomenon in compression and reset process for a long time, that is: reset force is insufficient after compression, and sealing property of valve plate declines, and valve body needs to be disassembled to replace spring, which is inconvenient. UTILITY MODEL CONTENTS

[0004] The utility model discloses a check valve for liquefied natural gas.

[0005] To achieve the above object, the utility model provides the following technical scheme: a check valve for liquefied natural gas, including valve body, the top of valve body is installed with lower connecting flange, lower connecting flange is fixedly installed with upper connecting flange through bolt, screw cap, sealing element is installed on the butt joint surface of lower connecting flange and upper connecting flange, the bottom of upper connecting flange is integrally formed with the sleeve that projects downward, the top of sleeve is open structure, the replaceable elastic mechanism extending to the inner chamber of sleeve is installed on the top of upper connecting flange, and sealing mechanism is installed between the outer periphery of sleeve and the inner wall of valve body.

[0006] As a further scheme of the utility model: one end of the inside of valve body is air inlet, the other end of the inside of valve body is air outlet, and the intersection position of air inlet and air outlet is formed with the inward projecting retaining ring.

[0007] As a further scheme of the utility model: the lifting rod extending to the below of sleeve is slidably connected on the inner wall of sleeve, the sealing plug is integrally formed on the bottom of lifting rod, the outer periphery of sealing plug is formed with the first taper surface, the upper inner periphery of retaining ring is formed with the second taper surface, the first taper surface and second taper surface are matched, and the lower inner periphery of retaining ring is formed with the transition taper surface.

[0008] As a further scheme of the utility model: the replaceable elastic mechanism includes the spring installed on the inner wall of sleeve, the threaded connecting disc is threadedly connected on the top opening of sleeve, the threaded connecting disc in the state of being screwed is abutted with the top of spring, and the top of threaded connecting disc is fixedly installed with handle.

[0009] As a further scheme of the utility model: the sealing mechanism includes an upper baffle integrally formed on the outer periphery of the sleeve and a lower baffle integrally formed on the inner periphery of the straight cylinder portion of the valve body, a lower extrusion conical surface is formed at the bottom end of the upper baffle, an upper extrusion conical surface is formed at the top end of the lower baffle, and an extrusion type sealing ring is installed on the abutting surface of the upper extrusion conical surface and the lower extrusion conical surface.

[0010] As a further scheme of the utility model: the second conical surface is installed with a sealing element abutting against the first conical surface.

[0011] Compared with the prior art, the utility model has the beneficial effects that:

[0012] 1. By setting the replaceable elastic mechanism, the spring can be replaced alone without disassembling the valve body, and the natural gas leakage does not occur in the replacement process, so that the spring replacement efficiency is higher, and the replacement safety is better. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 It is a structural schematic view of the utility model;

[0014] Figure 2 It is an internal structural schematic view of the utility model;

[0015] Figure 3 It is a Figure 2 It is a local enlarged view of A in the middle.

[0016] In the drawing: 1, valve body; 2, lower connecting flange; 3, upper connecting flange; 4, threaded connecting disc; 5, handle; 6, air inlet; 7, air outlet; 8, baffle ring; 9, sleeve; 10, spring; 11, lifting rod; 12, sealing plug; 13, upper baffle; 14, lower baffle; 15, extrusion type sealing ring. DETAILED DESCRIPTION

[0017] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the utility model.

[0018] Please refer to Figures 1-3The utility model discloses an embodiment of a check valve for liquefied natural gas, which comprises a valve body 1, a lower connecting flange 2 is installed on the top of the valve body 1, the lower connecting flange 2 is fixedly installed with an upper connecting flange 3 through bolts and nuts, a sealing element is installed on the butt joint surface of the lower connecting flange 2 and the upper connecting flange 3, a sleeve 9 protruding downward is integrally formed at the bottom end of the upper connecting flange 3, the top of the sleeve 9 is in an open structure, a replaceable elastic mechanism extending into the inner cavity of the sleeve 9 is installed on the top of the upper connecting flange 3, a sealing mechanism is distributed and installed between the outer periphery of the sleeve 9 and the inner wall of the valve body 1, a lifting rod 11 extending downward of the sleeve 9 is slidably connected to the inner wall of the sleeve 9, a sealing plug 12 is integrally formed at the bottom end of the lifting rod 11, a first taper surface is formed on the outer periphery of the sealing plug 12, a second taper surface is formed on the upper inner periphery of a retaining ring 8, the first taper surface and the second taper surface are matched, a transition taper surface is formed on the lower inner periphery of the retaining ring 8, and a sealing element abutting against the first taper surface is installed on the second taper surface.

[0019] In the embodiment, when the air inlet starts, the air pressure acts on the bottom of the sealing plug 12, the sealing plug 12 moves upward under the pressure and pushes the lifting rod 11 to move upward on the inner wall of the sleeve 9, at this time, a gap for the outward transmission of the gas appears between the sealing plug 12 and the retaining ring 8, and the transition taper surface at the bottom end of the retaining ring 8 can effectively reduce the resistance of the gas movement, when the air inlet stops, the air pressure acting on the bottom of the sealing plug 12 gradually decreases, at this time, the sealing plug 12 resets, the first taper surface and the second taper surface are tightly attached by the resetting sealing plug 12, the sealing element between the first taper surface and the second taper surface is deformed under the pressure, the backflow of the gas is avoided, and the check function is realized.

[0020] When the spring 10 is insufficient in the resetting force due to metal fatigue in the long-time use, the spring 10 can be replaced by opening the replaceable elastic mechanism, so that the resetting force of the sealing plug 12 is maintained, when the sealing plug 12 is abraded for a long time and the air tightness is reduced, the valves on the connecting pipelines at both ends of the valve body 1 are closed first, then the connecting bolts of the upper connecting flange 3 and the lower connecting flange 2 are disassembled, the sealing plug 12 can be taken out, and the new upper connecting flange 3 and the components connected with the upper connecting flange 3 can be replaced.

[0021] Please refer to Figure 2 , one end of the inside of the valve body 1 is an air inlet channel 6, the other end of the inside of the valve body 1 is an air outlet channel 7, and the retaining ring 8 protruding inward is formed at the joint position of the air inlet channel 6 and the air outlet channel 7.

[0022] In the embodiment, the gas enters the air inlet channel 6 through the air inlet pipe, enters the air outlet channel 7 through the air inlet channel 6, and is then output to the air outlet pipe through the air outlet channel 7.

[0023] Please refer to Figure 2The replaceable elastic mechanism comprises a spring 10 mounted on the inner wall of the sleeve 9, and a threaded connecting disc 4 is threadedly connected to the top opening of the sleeve 9, and the threaded connecting disc 4 is in abutment with the top of the spring 10 in the screwed state, and a handle 5 is fixedly mounted on the top of the threaded connecting disc 4.

[0024] In the embodiment, when the spring 10 is replaced, the threaded connecting disc 4 is rotated by rotating the handle 5, and the threaded connecting disc 4 is screwed upwards until the threaded connecting disc 4 is completely separated from the sleeve 9 due to the threaded connection between the threaded connecting disc 4 and the inner wall of the sleeve 9, and then the spring 10 can be taken out and replaced with a new spring 10, and after the replacement is completed, the threaded connecting disc 4 is reversely rotated to be threadedly connected with the inner thread of the sleeve 9, so that the spring 10 can be replaced without gas leakage, and the valve body 1 does not need to be disassembled, and the replacement efficiency is higher and the safety is higher.

[0025] Please refer to Figure 3 The sealing mechanism comprises an upper baffle 13 integrally formed on the outer periphery of the sleeve 9 and a lower baffle 14 integrally formed on the inner periphery of the straight cylinder portion of the valve body 1, the bottom end of the upper baffle 13 is formed with a lower extrusion conical surface, the top end of the lower baffle 14 is formed with an upper extrusion conical surface, and an extrusion type sealing ring 15 is mounted on the abutment surface between the upper extrusion conical surface and the lower extrusion conical surface.

[0026] In the embodiment, when the upper connecting flange 3 and the various components connected with the upper connecting flange 3 are replaced, after the old upper connecting flange 3 is disassembled, the new upper connecting flange 3 and the matched components are replaced, then the new upper connecting flange 3 is butt-jointed with the lower connecting flange 2 and locked by bolts and nuts, at this time, the sleeve 9 moving downwards drives the lower extrusion conical surface of the upper baffle 13 to tightly abut against the upper extrusion conical surface of the lower baffle 14, at this time, the extrusion type sealing ring 15 is deformed under stress to completely block the gap between the upper extrusion conical surface and the lower extrusion conical surface, thereby further improving the sealing performance of the butt joint.

[0027] The above is only a preferred specific embodiment of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can make equivalent replacement or change according to the technical scheme and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A check valve for liquefied natural gas comprising a valve body (1), characterized in that, The top of the valve body (1) is provided with a lower connecting flange (2), the lower connecting flange (2) is fixedly provided with an upper connecting flange (3) through bolts and nuts, the butt joint surface of the lower connecting flange (2) and the upper connecting flange (3) is provided with a sealing element, the bottom end of the upper connecting flange (3) is integrally formed with a downwardly protruding sleeve (9), the top of the sleeve (9) is of an open structure, the top of the upper connecting flange (3) is provided with a replaceable elastic mechanism extending into the inner cavity of the sleeve (9), and the outer periphery of the sleeve (9) and the inner wall of the valve body (1) are provided with sealing mechanisms.

2. The check valve for use in liquefied natural gas according to claim 1, characterized by One end of the valve body (1) is provided with an air inlet channel (6), the other end of the valve body (1) is provided with an air outlet channel (7), and the intersection position of the air inlet channel (6) and the air outlet channel (7) is formed with an inwardly protruding blocking ring (8).

3. A check valve for use with liquefied natural gas according to claim 2, wherein The inner wall of the sleeve (9) is slidably connected with a lifting rod (11) extending below the sleeve (9), the bottom end of the lifting rod (11) is integrally formed with a sealing plug (12), the outer periphery of the sealing plug (12) is formed with a first taper surface, the upper inner periphery of the blocking ring (8) is formed with a second taper surface, the first taper surface and the second taper surface are matched, and the lower inner periphery of the blocking ring (8) is formed with a transition taper surface.

4. The check valve for use in liquefied natural gas according to claim 1, wherein The replaceable elastic mechanism comprises a spring (10) mounted on the inner wall of the sleeve (9), and a threaded connecting disc (4) is threadedly connected to the top opening of the sleeve (9), the threaded connecting disc (4) in a screwed state abuts against the top of the spring (10), and a handle (5) is fixedly mounted on the top of the threaded connecting disc (4).

5. A check valve for use with liquefied natural gas according to claim 4, wherein The sealing mechanism comprises an upper baffle (13) integrally formed on the outer periphery of the sleeve (9) and a lower baffle (14) integrally formed on the inner periphery of the straight cylinder portion of the valve body (1), the bottom end of the upper baffle (13) is formed with a lower extrusion taper surface, the top end of the lower baffle (14) is formed with an upper extrusion taper surface, and the abutting surface of the upper extrusion taper surface and the lower extrusion taper surface is provided with an extrusion type sealing ring (15).

6. The check valve for use in liquefied natural gas according to claim 3, wherein The second taper surface is provided with a sealing element abutting against the first taper surface.

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