A low temperature test sealing device for LNG valve connection end with extended pipe

Abstract

The present invention belongs to a sealing device, and specifically relates to a low-temperature test sealing device for a LNG valve connection end with an extended pipe. A low-temperature test sealing device for a LNG valve connection end with an extended pipe comprises a head, a sealing ring, a sealing gasket, a disc spring and an adapter. The significant effect of the present invention is: a low-temperature test sealing device for a LNG valve connection end with an extended pipe, through which the sealing device well solves the sealing leakage problem of the connection end when the LNG valve is pressure tested at a low temperature of ‑196°C, with reasonable design, simple structure and reliable low-temperature sealing.

Description

Technical Field

[0001] The invention belongs to a sealing device, and in particular relates to a low-temperature test sealing device for an LNG valve connection end with an extended connecting pipe. Background Art

[0002] The working temperature of LNG (liquefied natural gas) valves is as low as -165℃, and the working conditions are harsh, with strict requirements for leakage. In order to ensure the low-temperature sealing performance of the valve, the valve should meet the sealing performance requirements when tested under low-temperature conditions of -196℃. First, after passing the normal temperature pressure test, a low-temperature sealing test is then carried out at a low temperature of -196℃ to verify the performance of the valve at low temperatures. Since both metal materials and non-metallic materials will shrink to varying degrees at low temperatures, the reliable sealing method of the normal temperature sealing test will produce varying degrees of leakage at low temperatures, which directly affects the accuracy of the valve sealing test results, and even causes the valve low-temperature sealing test to be unable to proceed normally. Summary of the invention

[0003] The present invention aims at the defects of the prior art and provides a low temperature test sealing device for the connection end of an LNG valve with an extended pipe.

[0004] The present invention is realized in this way: a low temperature test sealing device for an LNG valve connection end with an extended pipe comprises a sealing head, a sealing ring, a sealing gasket, a disc spring and a switching joint.

[0005] A low temperature test sealing device for the connection end of an LNG valve with an extended pipe as described above, wherein the sealing head is provided with an internal thread, and the internal thread is connected to the external thread of the extended pipe of the valve;

[0006] The low temperature test sealing device for the connection end of the LNG valve with an extended pipe as described above, wherein a flat bottom hole is provided at the bottom of the head, and the flat bottom hole matches the outer circle of the sealing gasket boss; the head is provided with a hexagonal structure for tightening the head;

[0007] As described above, a low-temperature test sealing device for the connection end of an LNG valve with an extended pipe is provided, wherein a through hole is opened in the center of the head, the through hole is connected to the center hole of the sealing gasket and the valve channel; the head is connected to the adapter by welding.

[0008] As described above, a low-temperature test sealing device for the connection end of an LNG valve with an extended connecting pipe is provided, wherein the sealing gasket is a gasket with a boss, the outer circle of the boss matches the flat-bottom hole of the head, one end matches the inner diameter of the disc spring, and the other end matches the inner diameter of the valve connecting pipe, and a through hole is provided in the center, which is connected to the center hole of the head and the valve channel.

[0009] As described above, a low-temperature test sealing device for the connection end of an LNG valve with an extended pipe is provided, wherein the sealing ring is an annular structure, and the inner and outer circles respectively cooperate with the head and the sealing gasket, and is installed in a cavity formed between the head, the sealing gasket and the end of the extended pipe of the valve.

[0010] As described above, a low-temperature test sealing device for the connection end of an LNG valve with an extended pipe is provided, wherein the disc spring is a sealing force compensation mechanism, which provides sealing compensation force during the low-temperature test to achieve sealing of the connection end, and is installed in a cavity formed between the head and the sealing gasket.

[0011] As described above, a low-temperature test sealing device for the connection end of an LNG valve with an extended pipe, wherein one end of the adapter is connected to the head and the other end is connected to the test control equipment, is applied to the air inlet end and the leak detection end of the valve.

[0012] The remarkable effect of the present invention is: a low-temperature test sealing device for the connection end of an LNG valve with an extended pipe, which well solves the sealing leakage problem of the connection end when the LNG valve is pressure tested at a low temperature of -196°C, has a reasonable design, a simple structure, and reliable low-temperature sealing. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a schematic diagram of the structure and use of a low-temperature test sealing device for a connection end of an LNG valve with an extended pipe according to the present invention;

[0014] Figure 2 It is a schematic diagram of the head structure;

[0015] Figure 3 Schematic diagram of the sealing gasket structure;

[0016] Explanation of the reference numerals in the accompanying drawings: 1-end cap; 2-sealing gasket; 3-sealing ring; 4-valve (diagram of test valve); 5-disc spring; 6-adapter; 21-flat bottom hole; 22-internal thread; 23-hexagonal structure; 31-disc spring positioning shoulder; 32-sealing shoulder; 33-loading guide DETAILED DESCRIPTION

[0017] The following is an explanation with reference to specific implementation examples.

[0018] The present invention provides a low temperature test sealing device for the connection end of an LNG valve with an extended pipe, such as Figure 1 As shown, it includes a head 1, a sealing gasket 2, a sealing ring 3, a disc spring 5 and an adapter 6.

[0019] The end cap 1 is provided with an internal thread 22, which is connected to the external thread of the extended pipe of the valve 4; the end cap 1 is provided with a flat bottom hole 21 at the bottom, which matches the outer circle of the boss of the sealing gasket 2; the end cap 1 is provided with a hexagonal structure 23 for tightening the end cap 1; a through hole is opened in the center of the end cap 1, which is connected to the center hole of the sealing gasket 2 and the channel of the valve 4; the end cap 1 is connected to the adapter 6 by welding;

[0020] The sealing gasket 2 is a gasket with a boss, the outer circle of the boss matches the flat bottom hole 21 of the head 1, one end matches the inner diameter of the disc spring 5, that is, the disc spring positioning shoulder 31, and the other end matches the inner diameter of the valve 4 pipe, that is, the guide 33, and a through hole is provided in the center, which is connected with the center hole of the head 1 and the valve 4 channel;

[0021] The sealing ring 3 is an annular structure, and the inner and outer circles are matched with the sealing gasket 2 and the head 1 respectively, and is installed in the cavity formed between the head 1, the sealing gasket 2 and the end of the extended pipe of the valve 4;

[0022] The disc spring 5 is a sealing force compensation mechanism, which provides sealing compensation force during the low temperature test to achieve the sealing of the connection end, and is installed in the cavity formed between the head 1 and the sealing gasket 2, on the disc spring positioning shoulder 31;

[0023] One end of the adapter 6 is connected to the sealing head 1 , and the other end is connected to the test control equipment, and is applied to the air inlet end and the leak detection end of the valve 4 .

[0024] The implementation mechanism of the present invention is as follows: first, assemble at room temperature, connect the internal thread 22 of the head 1 with the external thread of the extended pipe of the valve 4, tighten the head 1, realize pre-compression of the disc spring 5, and press the sealing ring 3. When the disc spring 5 is compressed to the maximum limit, the left end of the sealing gasket 2 contacts the bottom of the flat-bottom hole of the head 1, so as to achieve the best seal at the end of the connecting pipe, and at the same time play the role of pressing the sealing ring 3 and protecting the disc spring 5; during the low-temperature test, the pre-compressed disc spring 5 acts as a sealing force compensation mechanism to compensate for the deformation and contraction of the head 1, the sealing gasket 2, the sealing ring 3, the valve 4, the disc spring 5 and the adapter 6 on the sealing of the connecting end, and provide sealing compensation force, so as to ensure the sealing of the connecting end of the extended pipe of the valve 4 at low temperature.

Claims

1. A low temperature test sealing device for LNG valve connection end with an extended pipe, characterized in that: It includes a head, a sealing ring, a sealing gasket, a disc spring and an adapter; The sealing head is provided with an internal thread, which is connected with the external thread of the valve extension pipe; A flat bottom hole is provided at the bottom of the head, which matches the outer circle of the sealing gasket boss; the head is provided with a hexagonal structure for tightening the head; A through hole is opened in the center of the head, which is connected with the center hole of the sealing gasket and the valve channel; the head is connected to the adapter by welding; The sealing gasket is a gasket with a boss, the outer circle of the boss matches the flat bottom hole of the head, one end matches the inner diameter of the disc spring, and the other end matches the inner diameter of the valve pipe. A through hole is provided in the center, which is connected with the center hole of the head and the valve channel; The sealing ring is an annular structure, and its inner and outer circles cooperate with the head and the sealing gasket respectively, and is installed in the cavity formed between the head, the sealing gasket and the end of the valve extension pipe.

2. The low temperature test sealing device for the connection end of an LNG valve with an extended pipe according to claim 1 is characterized in that: The disc spring is a sealing force compensation mechanism that provides sealing compensation force during low-temperature testing to achieve sealing at the connection end. It is installed in the cavity formed between the head and the sealing gasket.

3. The low temperature test sealing device for the connection end of an LNG valve with an extended pipe according to claim 2 is characterized in that: One end of the adapter is connected to the end cap, and the other end is connected to the test control equipment. It is used at the air inlet end and leak detection end of the valve.

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