CN115854064A

CN115854064A - On-line setting automatic switcher for low-pressure safety valve

Info

Publication number: CN115854064A
Application number: CN202211729875.6A
Authority: CN
Inventors: 洪庆东; 陈刚; 崔敬陶; 吴德河
Original assignee: Ouchuange Valve Co ltd
Current assignee: Ouchuange Valve Co ltd
Priority date: 2022-12-30
Filing date: 2022-12-30
Publication date: 2023-03-28

Abstract

The invention discloses an automatic on-line setting switcher for a low-pressure safety valve, which comprises a valve body, an upper valve cover and a lower valve cover, wherein the upper valve cover is arranged on the valve body; a first air inlet hole is formed in the left side of the valve body, a second air inlet hole is formed in the right side of the valve body, a central hole is formed in the middle of the valve body, and an air outlet hole is formed in the rear side of the valve body; the upper valve cover is fixed at the upper end of the valve body, an upper diaphragm is hermetically fixed between the upper valve cover and the valve body, a first vent hole is formed in the upper end of the valve body, and a first air guide hole used for communicating a second air inlet hole with the upper concave cavity is formed in the valve body, the upper diaphragm and the upper valve cover; the lower valve cover is fixed at the lower end of the valve body, a lower diaphragm is fixed between the lower valve cover and the valve body in a sealing mode, a second vent hole is formed in the lower end of the valve body, and a second vent hole used for communicating the first air inlet hole with the lower concave cavity is formed in the valve body, the lower diaphragm and the lower valve cover; the invention can realize the on-line setting of the pilot-operated low-pressure safety valve only by directly inputting the setting gas source.

Description

On-line setting automatic switcher for low-pressure safety valve

Technical Field

The invention relates to the technical field of low-pressure safety valve accessories, in particular to an automatic on-line setting switcher for a low-pressure safety valve.

Background

The low-pressure safety valve is a valve which can ensure that the space of the storage tank is isolated from the atmosphere within a certain pressure range and can be communicated with the atmosphere (breathing) when the pressure exceeds or is lower than the pressure range, and the low-pressure safety valve has the functions of preventing the storage tank from being damaged due to overpressure or vacuum and reducing the evaporation loss of the stored liquid.

The low-pressure safety valve is used for maintaining the air pressure balance of the storage tank, when the pressure in the tank rises and reaches the operation positive pressure of the low-pressure safety valve, the valve is breathed to act, and gas escapes from the low-pressure safety valve from a breathing port, so that the pressure in the tank does not increase continuously; when the pressure in the tank drops and reaches the operation negative pressure of the low-pressure safety valve, the valve clack assembly of the suction valve is jacked open by the atmosphere outside the tank, so that the external gas enters the tank, the pressure in the tank does not drop continuously, and the air pressure inside the tank and outside the tank is balanced to protect the storage tank.

Common low-pressure safety valves (breather valves) are divided into gravity plate type, spring type and pilot type, and compared with common gravity loading type and spring type breather valves, the pilot type breather valve has higher sealing performance, and can reach full displacement when overpressure is lower than 10%, so that the operating pressure of the pilot type breather valve can be very close to the maximum design pressure of a storage tank, evaporation loss is reduced, and economic performance is improved.

However, the pilot-operated low-pressure safety valves are complex in structure and need to be calibrated regularly, and most of the pilot-operated low-pressure safety valves are installed at the top of a large storage tank, so that the pilot-operated low-pressure safety valves are inconvenient to disassemble and install; therefore, an online setting mode adopted by the pilot-operated low-pressure safety valve is the optimal selection, the current common online setting mode is switching by using a three-way ball valve, and the risk of misoperation exists in practical use.

Disclosure of Invention

Aiming at the defects of the prior art, the invention provides an automatic on-line setting switcher for a low-pressure safety valve, which is used for setting a pilot-operated low-pressure safety valve, only a second connector is required to be connected with a setting air source, the automatic setting switcher can automatically select the first air inlet to be communicated with an air outlet or automatically select the second air inlet to be communicated with the air outlet according to the air pressure in a first air inlet and the air pressure in a second air inlet, namely, the switching is not required to be carried out in a manual mode, and therefore, the risk caused by misoperation of personnel can be avoided.

The invention relates to an on-line setting automatic switcher for a low-pressure safety valve, which comprises a valve body, an upper valve cover and a lower valve cover; the left side of the valve body is provided with a first air inlet, the first air inlet is connected with the pressure sampling pipe through a first joint, the right side of the valve body is provided with a second air inlet, the second air inlet is connected with the plugging cap through a second joint, the middle part of the valve body is provided with a central hole which vertically penetrates through the valve body, the rear side of the valve body is provided with an air outlet communicated with the central hole, and the air outlet is connected with a pilot valve connecting pipe through a third joint; the upper valve cover is fixed at the upper end of the valve body, an upper diaphragm is hermetically fixed between the upper valve cover and the valve body, the lower surface of the upper diaphragm abuts against and is sealed with the outer edge of the upper end of the central hole, an upper concave cavity with an opening at the lower end is arranged in the middle of the lower end surface of the upper valve cover, a first vent hole for communicating a first air inlet hole with the central hole is arranged at the upper end of the valve body, and first air guide holes for communicating a second air inlet hole with the upper concave cavity are arranged on the valve body, the upper diaphragm and the upper valve cover; the lower valve cover is fixed at the lower end of the valve body, a lower diaphragm is hermetically fixed between the lower valve cover and the valve body, the upper surface of the lower diaphragm abuts against and is sealed with the outer edge of the lower end of the central hole, a lower concave cavity with an upper end opening is arranged in the middle of the upper end surface of the lower valve cover, a second vent hole used for communicating a second air inlet hole with the central hole is arranged at the lower end of the valve body, and a second air guide hole used for communicating a first air inlet hole with a lower concave cavity is arranged on the valve body, the lower diaphragm and the lower valve cover.

By adopting the structure, when the pilot-operated low-pressure safety valve is set, only the second connector needs to be connected with the setting air source, the pilot-operated low-pressure safety valve can automatically select the first air inlet to be communicated with the air outlet hole or automatically select the second air inlet to be communicated with the air outlet hole according to the air pressure in the first air inlet hole and the air pressure in the second air inlet hole, namely, the pilot-operated low-pressure safety valve does not need to be switched in a manual mode, so that the risk caused by misoperation of personnel can be avoided; in addition, the pilot-operated low-pressure safety valve can be set on line only by directly inputting a setting gas source, so that convenience can be brought to workers.

The automatic on-line setting switcher for the low-pressure safety valve is characterized in that a first annular recess is formed in the upper end face of a valve body, the upper end of a first vent hole is communicated with the first annular recess, and the lower surface of an upper membrane is abutted against and sealed with the upper ends of two sides of the first annular recess; after the first annular recess is formed in the upper end face of the valve body, when the plug is taken down from the second connector and the second connector is connected with the setting air source, if the air pressure from the pressure taking pipe is larger than the air pressure of the setting air source, the air from the pressure taking pipe can reliably act on the lower surface of the upper membrane (acts on the lower surface of the upper membrane in an annular mode) through the first vent hole and the first annular recess, so that the middle of the upper membrane can be jacked upwards more easily, and even if the air from the pressure taking pipe enters the central hole and enters the third connector and the pilot valve connecting pipe through the vent hole.

The low-pressure safety valve on-line setting automatic switcher comprises a valve body, a first annular recess, a first vent hole, a second annular recess, a lower diaphragm, a first diaphragm, a second diaphragm, a first diaphragm and a second diaphragm, wherein the lower end face of the valve body is provided with the first annular recess; after the second annular recess is arranged on the lower end face of the valve body, when the plug is taken down from the second joint and the second joint is connected with the setting air source, if the air pressure from the pressure taking pipe is smaller than that of the setting air source, the air from the setting air source can more reliably act on the upper surface of the lower membrane through the second vent hole and the second annular recess (act on the upper surface of the lower membrane in an annular mode), so that the middle part of the lower membrane can be more easily jacked up downwards, and even if the air from the setting air source enters the central hole and enters the third joint and the pilot valve connecting pipe through the vent hole.

The automatic switcher is used for online setting of the low-pressure safety valve, wherein a first annular bending edge is arranged at the outer edge of an upper diaphragm, and the first annular bending edge is pressed and fixed between an upper valve cover and the upper end of a valve body; by adopting such a structure, the upper diaphragm can be reliably fixed in a sealed manner between the upper bonnet and the upper end of the valve body.

The automatic on-line setting switcher for the low-pressure safety valve is characterized in that a second annular bending edge is arranged at the outer edge of a lower diaphragm, and the second annular bending edge is pressed and fixed between a lower valve cover and the lower end of a valve body; by adopting such a structure, the lower diaphragm can be reliably fixed in a sealing manner between the lower bonnet and the lower end of the valve body.

The low-pressure safety valve on-line setting automatic switcher comprises an upper diaphragm, a lower diaphragm, a first switch and a second switch, wherein the upper diaphragm and the lower diaphragm are both made of polytetrafluoroethylene materials; after the upper diaphragm and the lower diaphragm are made of polytetrafluoroethylene, the freezing condition between the upper diaphragm and the valve body and between the lower diaphragm and the valve body can be avoided in a low-temperature state.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the application and together with the description serve to explain the application and not to limit the application. In the drawings:

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a schematic perspective sectional view of the present invention;

FIG. 3 is an enlarged view of the structure at A in FIG. 2;

FIG. 4 is an enlarged view of the structure at B in FIG. 2;

FIG. 5 is a schematic diagram of the present invention in normal operation;

FIG. 6 is a schematic diagram of the present invention during on-line alignment.

Detailed Description

In the following description, for purposes of explanation, numerous implementation details are set forth in order to provide a thorough understanding of various embodiments of the present invention. It should be understood, however, that these implementation details should not be taken to limit the invention. That is, in some embodiments of the invention, such implementation details are not necessary. In addition, some conventional structures and components are shown in simplified schematic form in the drawings for the sake of simplicity.

In addition, the descriptions related to the first, the second, etc. in the present invention are only used for description purposes, do not particularly refer to an order or sequence, and do not limit the present invention, but only distinguish components or operations described in the same technical terms, and are not understood to indicate or imply relative importance or implicitly indicate the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory 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. 1-4, the automatic on-line setting switcher for the low-pressure safety valve of the invention comprises a valve body 1, an upper valve cover 2 and a lower valve cover 3; a first air inlet hole 11 is formed in the left side of the valve body 1, the first air inlet hole 11 is connected with a pressure sampling pipe 42 through a first connector 41, a second air inlet hole 12 is formed in the right side of the valve body 1, the second air inlet hole 12 is connected with a blocking cap 52 through a second connector 51, a central hole 13 vertically penetrating through the valve body 1 is formed in the middle of the valve body 1, an air outlet hole 14 communicated with the central hole 13 is formed in the rear side of the valve body 1, and the air outlet hole 14 is connected with a pilot valve connecting pipe 62 through a third connector 61; the upper valve cover 2 is fixed at the upper end of the valve body 1, an upper diaphragm 7 is hermetically fixed between the upper valve cover 2 and the valve body 1, the lower surface of the upper diaphragm 7 abuts against and is sealed with the outer edge of the upper end of the central hole 13, an upper concave cavity 21 with an open lower end is arranged in the middle of the lower end surface of the upper valve cover 2, a first vent hole 15 for communicating a first air inlet hole 11 with the central hole 13 is arranged at the upper end of the valve body 1, and a first air guide hole 16 for communicating a second air inlet hole 12 with the upper concave cavity 21 is arranged on the valve body 1, the upper diaphragm 7 and the upper valve cover 2; the lower valve cover 3 is fixed at the lower end of the valve body 1, a lower diaphragm 8 is hermetically fixed between the lower valve cover 3 and the valve body 1, the upper surface of the lower diaphragm 8 abuts against and is sealed with the outer edge of the lower end of the central hole 13, a concave cavity 31 with an open upper end is arranged in the middle of the upper end surface of the lower valve cover 3, a second vent hole 17 used for communicating the second air inlet hole 12 with the central hole 13 is arranged at the lower end of the valve body 1, and a second vent hole 18 used for communicating the first air inlet hole 11 with the concave cavity 31 is arranged on the valve body 1, the lower diaphragm 8 and the lower valve cover 3.

A first annular recess 191 is formed in the upper end face of the valve body 1, the upper end of the first vent hole 15 is communicated with the first annular recess 191, and the lower surface of the upper diaphragm 7 is abutted against and sealed with the upper ends of two sides of the first annular recess 191; after the first annular recess is arranged on the upper end face of the valve body, when the plug is taken down from the second connector and the second connector is connected with the setting air source, if the air pressure from the pressure taking pipe is greater than the air pressure of the setting air source, the air from the pressure taking pipe can more reliably act on the lower surface of the upper diaphragm through the first vent hole and the first annular recess (acts on the lower surface of the upper diaphragm in an annular mode), so that the middle part of the upper diaphragm can be more easily jacked up, and even if the air from the pressure taking pipe enters the central hole and enters the third connector and the pilot valve connecting pipe through the air outlet hole.

A second annular recess 192 is formed in the lower end face of the valve body 1, the lower end of the second vent hole 17 is communicated with the second annular recess 192, and the upper surface of the lower diaphragm 8 is abutted against and sealed with the lower ends of the two sides of the second annular recess 192; after the second annular recess is arranged on the lower end face of the valve body, when the plug is taken down from the second joint and the second joint is connected with the setting air source, if the air pressure from the pressure taking pipe is smaller than that of the setting air source, the air from the setting air source can more reliably act on the upper surface of the lower membrane through the second vent hole and the second annular recess (act on the upper surface of the lower membrane in an annular mode), so that the middle part of the lower membrane can be more easily jacked up downwards, and even if the air from the setting air source enters the central hole and enters the third joint and the pilot valve connecting pipe through the vent hole.

A first annular bending edge 71 is arranged at the outer edge of the upper diaphragm 7, and the first annular bending edge 71 is pressed and fixed between the upper valve cover 2 and the upper end of the valve body 1; by adopting such a structure, the upper diaphragm can be reliably sealingly fixed between the upper bonnet and the upper end of the valve body.

A second annular bending edge 81 is arranged at the outer edge of the lower diaphragm 8, and the second annular bending edge 81 is pressed and fixed between the lower valve cover 3 and the lower end of the valve body 1; by adopting such a structure, the lower diaphragm can be reliably fixed in a sealing manner between the lower bonnet and the lower end of the valve body.

The upper diaphragm 7 and the lower diaphragm 8 are both made of polytetrafluoroethylene materials; after the upper diaphragm and the lower diaphragm are made of polytetrafluoroethylene, the freezing condition between the upper diaphragm and the valve body and between the lower diaphragm and the valve body can be avoided in a low-temperature state.

As shown in fig. 5, the automatic on-line setting switch for the low-pressure safety valve is a high-pressure selector, which sends the gas with high pressure in the first gas inlet hole and the second gas inlet hole to the gas outlet hole, and the principle is as follows: when the air pressure P1 in the first air inlet hole is larger than the air pressure P0 in the second air inlet hole, the air pressure borne by the bottom of the upper diaphragm is P1, the air pressure borne by the top of the upper diaphragm is P0, the upper diaphragm is opened under an upward acting force, the air pressure difference value is delta P = P1-P0, and the acting area is the whole upper diaphragm; the air pressure borne by the bottom of the lower diaphragm is P1, the air pressure borne by the top of the lower diaphragm is P0, the air pressure in the central hole is P1, the lower diaphragm is closed by upward acting force, the air pressure difference value is delta P = P1-P0, and the acting area is the annular area of the outer ring of the lower diaphragm, so that the air pressure P1 can be obtained by the air outlet hole and cannot be leaked into a setting air source.

As shown in fig. 6, when the on-line setting automatic switch of the low-pressure safety valve is set on line, the second joint is connected to the setting air source, and the air pressure P2 of the setting air source is greater than the air pressure P1 in the first air inlet, and the principle at this time is as follows: when the air pressure P2 of the setting air source is greater than the air pressure P1 in the first air inlet hole, the air pressure borne by the bottom of the lower diaphragm is P1, the air pressure borne by the top of the lower diaphragm is P2, the lower diaphragm is opened under the action of downward force, the air pressure difference value is delta P = P2-P1, and the action area is the whole lower diaphragm; the air pressure value borne by the top of the upper diaphragm is P2, the air pressure value borne by the annular area of the outer ring of the bottom of the upper diaphragm is P1, the air pressure value in the central hole is P2, the upper diaphragm is closed by downward acting force, the air pressure difference value is delta P = P2-P1, the acting area is the annular area of the outer ring of the upper diaphragm, and therefore the air pressure P2 can be obtained through the air outlet hole and cannot be leaked into the pressure taking pipe.

The above description is only an embodiment of the present invention, and is not intended to limit the present invention. Various modifications and alterations to this invention will become apparent to those skilled in the art. Any modification, equivalent replacement, improvement or the like made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The utility model provides an automatic switch-over ware is set on line to low pressure relief valve which characterized in that: comprises a valve body (1), an upper valve cover (2) and a lower valve cover (3); a first air inlet hole (11) is formed in the left side of the valve body (1), the first air inlet hole (11) is connected with a pressure sampling pipe (42) through a first connector (41), a second air inlet hole (12) is formed in the right side of the valve body (1), the second air inlet hole (12) is connected with a blocking cap (52) through a second connector (51), a central hole (13) which vertically penetrates through the valve body (1) is formed in the middle of the valve body (1), an air outlet hole (14) communicated with the central hole (13) is formed in the rear side of the valve body (1), and the air outlet hole (14) is connected with a pilot valve connecting pipe (62) through a third connector (61); the upper valve cover (2) is fixed at the upper end of the valve body (1), an upper diaphragm (7) is hermetically fixed between the upper valve cover (2) and the valve body (1), the lower surface of the upper diaphragm (7) abuts against and is sealed with the outer edge of the upper end of the central hole (13), an upper cavity (21) with an opening at the lower end is arranged in the middle of the lower end surface of the upper valve cover (2), a first vent hole (15) for communicating a first air inlet hole (11) with the central hole (13) is arranged at the upper end of the valve body (1), and first air guide holes (16) for communicating a second air inlet hole (12) with the upper cavity (21) are arranged on the valve body (1), the upper diaphragm (7) and the upper valve cover (2); the lower extreme at valve body (1) is fixed in lower valve gap (3), be fixed with lower diaphragm (8) between lower valve gap (3) and valve body (1) sealedly, the upper surface of lower diaphragm (8) leans on and seals with the outward flange counterbalance of centre bore (13) lower extreme, the up end middle part of lower valve gap (3) is provided with upper end open-ended recessed chamber (31), the lower extreme of valve body (1) is provided with second vent hole (17) that are used for communicateing second inlet port (12) and centre bore (13), be provided with second vent hole (18) that are used for communicateing first inlet port (11) and recessed chamber (31) on valve body (1), lower diaphragm (8) and lower valve gap (3).

2. The on-line setting automatic switcher of the low-pressure safety valve according to claim 1, characterized in that a first annular recess (191) is arranged on the upper end surface of the valve body (1), the upper end of the first vent hole (15) is communicated with the first annular recess (191), and the lower surface of the upper diaphragm (7) is abutted and sealed with the upper ends of two sides of the first annular recess (191).

3. The low-pressure safety valve online setting automatic switcher according to claim 1, characterized in that a second annular recess (192) is provided on a lower end face of the valve body (1), a lower end of the second vent hole (17) communicates with the second annular recess (192), and an upper surface of the lower diaphragm (8) abuts and seals against lower ends of both sides of the second annular recess (192).

4. The automatic on-line setting switcher of low pressure safety valves according to any one of claims 1 to 3, characterized in that a first annular bending edge (71) is provided at the outer edge of the upper diaphragm (7), and the first annular bending edge (71) is press-fitted and fixed between the upper bonnet (2) and the upper end of the valve body (1).

5. The on-line setting automatic switcher of low pressure safety valves according to any of claims 1-3, characterized in that a second annular bending edge (81) is provided at the outer edge of the lower diaphragm (8), and the second annular bending edge (81) is press-fitted and fixed between the lower valve cover (3) and the lower end of the valve body (1).

6. The on-line setting automatic low-pressure safety valve switching device according to any one of claims 1 to 3, wherein the upper diaphragm (7) and the lower diaphragm (8) are made of polytetrafluoroethylene material.