CN212251159U

CN212251159U - Three-membrane-head double-pressure-taking ultra-micro-pressure nitrogen seal regulating valve

Info

Publication number: CN212251159U
Application number: CN202021924444.1U
Authority: CN
Inventors: 赵荣娟
Original assignee: Hangzhou Fuyang Lianggong Instrument Co ltd
Current assignee: Hangzhou Fuyang Lianggong Instrument Co ltd
Priority date: 2020-09-07
Filing date: 2020-09-07
Publication date: 2020-12-29
Anticipated expiration: 2030-09-07

Abstract

The utility model discloses a three-membrane-head double-pressure-taking ultra-micro-pressure nitrogen seal regulating valve, which comprises a valve body, a valve cover arranged on the valve body, a bracket arranged on the valve cover, a main valve membrane head arranged on the bracket, a commander arranged on the main valve membrane head and a commander membrane head arranged on the commander; the membrane head of the commander is divided into a first membrane head of the commander and a second membrane head of the commander; the first commander membrane head and the second commander membrane head are respectively connected with a first pressure sampling pipe and a second pressure sampling pipe; and a pressure relief pipe is connected between the main valve membrane head and the valve body. The utility model discloses an adopting three membrane head structures, the commander adopts two membrane heads, has just obtained the area of contact of twice in other words, under the same thrust, pressure just can reduce half behind the valve, can reach 0.1kpa at minimum to can reduce the nitrogen gas use amount of storage tank protective layer, and the nitrogen gas pressure of storage tank protective layer is lower behind the valve, and the pressure that chemical material received is little, thereby makes the material more stable, safer, the energy saving, reduce cost.

Description

Three-membrane-head double-pressure-taking ultra-micro-pressure nitrogen seal regulating valve

Technical Field

The utility model relates to a governing valve specifically indicates a three membrane head double-pressure taking surpasses and presses nitrogen and seals governing valve.

Background

The self-operated regulating valve drives the valve to automatically work by taking the pressure and the temperature of the medium flowing through the valve as energy sources without an external power supply and a secondary instrument, and is also called as a self-operated control valve, wherein a feedback signal (pressure, pressure difference and temperature) at the output end of the valve is transmitted to an actuating mechanism through a signal pipe to drive the valve clack to change the opening degree of the valve, so that the purposes of regulating the pressure, the flow and the temperature are achieved; the micro-pressure self-operated regulating valve in the self-operated regulating valve is generally used for micro-pressure control of various industrial gases such as nitrogen seal of a storage tank, coal gas, natural gas, liquefied gas, oxygen, nitrogen and the like, the conventional self-operated regulating valve has a complex structure, a large number of parts and great assembly difficulty, the conventional self-operated pressure regulating valve needs manual or mechanical control, the capacity of controlling the pressure fluctuation range is small, the pressure after the valve is not constant, energy can not be saved in the control aspect of the regulating valve due to input of manpower or machinery, a plurality of conventional regulating valves are provided with commanders on the regulating valves, the conventional market commonly uses a double-membrane head regulating valve, the pressure regulating precision can only reach 0.5kpa, the precision is not high, and therefore, the nitrogen consumption of a protective layer of the storage tank behind the valve is large, the energy consumption is large, and the cost is; the high pressure of the nitrogen in the storage tank causes the pressure received by the chemical materials in the storage tank to be larger, and the materials are easily subjected to change under the high-pressure extrusion; the pressure is got through single pressure-taking pipe to conventional two membrane head governing valves, and the admission speed is slow to lead to the valve reaction comparatively dull. Therefore, a three-membrane head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve is provided.

SUMMERY OF THE UTILITY MODEL

The utility model aims at solving the problems and providing a three-membrane head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve.

In order to achieve the purpose, the utility model provides a three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve, which comprises a valve body, a valve cover arranged on the valve body, a bracket arranged on the valve cover, a main valve membrane head arranged on the bracket, a commander arranged on the main valve membrane head and a commander membrane head arranged on the commander; the membrane head of the commander is divided into a first membrane head of the commander and a second membrane head of the commander; the first commander membrane head and the second commander membrane head are respectively connected with a first pressure sampling pipe and a second pressure sampling pipe; and a pressure relief pipe is connected between the main valve membrane head and the valve body.

Preferably, a guide sleeve is arranged between the valve body and the valve cover, a valve rod is slidably arranged on the guide sleeve, one end of the valve rod is provided with a valve core, and the other end of the valve rod is connected with a main valve push rod; the valve body is also provided with a valve seat; the main valve push rod penetrates through the bracket and then is connected with the main valve membrane head; the valve body is also provided with a valve front channel and a valve rear channel; and a first pressure guiding pipe is connected between the front valve channel and the commander, and a pressure reducer is installed on the first pressure guiding pipe.

Preferably, the main diaphragm head comprises a main lower diaphragm cover mounted on the support, a main upper diaphragm cover mounted on the main lower diaphragm cover, and a main diaphragm mounted between the main upper diaphragm cover and the main lower diaphragm cover, and the main diaphragm head forms a main upper chamber and a main lower chamber through the main diaphragm; the main valve push rod penetrates through the main valve lower membrane cover and then is fixedly connected with the main valve membrane; a tray is arranged on the main valve diaphragm, a spring guide post is arranged on the tray, and a spring is arranged on the spring guide post; the upper membrane cover of the main valve is connected with a pressure relief pipe, and the other end of the pressure relief pipe is connected with the rear channel of the valve; and a director is arranged on the upper membrane cover of the main valve.

Preferably, the commander comprises a commander valve body, the commander valve body is provided with a commander upper valve cavity and a commander lower valve cavity, a channel is arranged between the commander upper valve cavity and the commander lower valve cavity, a commander valve rod is slidably mounted on the channel, one end of the commander valve rod is connected with a commander valve core, and the other end of the commander valve rod is connected with a commander push rod; the commander valve body is also provided with a flow path, one end port of the flow path is communicated with the upper cavity of the main valve, the other end of the flow path is connected with a second pressure guiding pipe, and the other end of the second pressure guiding pipe is communicated with the lower cavity of the main valve; a needle valve is further mounted on the flow path through threads; a first commander membrane is arranged on the commander valve body; the surface of the director valve core is also provided with a rubber seal.

Preferably, the commander membrane head comprises a commander lower membrane cover arranged on the commander valve body, and the commander lower membrane cover is provided with a commander membrane and a commander upper membrane cover; the first commander membrane head is provided with a first commander membrane cavity and a second commander membrane cavity through a first commander membrane; the upper membrane cover of the first commander is provided with a first commander tray, and the push rod of the first commander penetrates through the lower membrane cover of the first commander, the first commander membrane and the first commander tray in sequence and is connected with the first commander push rod; a first pressure taking pipe is connected to the lower membrane cover of the commander; a connecting block is arranged on the upper membrane cover of the first commander, and a push rod of the first commander is connected with the connecting block in a sliding manner; and a second commander membrane head is arranged on the connecting block.

Preferably, the second commander membrane head comprises a second commander lower membrane cover arranged on the connecting block, a second commander membrane arranged on the second commander lower membrane cover, and a second commander upper membrane cover; the second commander membrane head is provided with a second commander upper membrane cavity and a second commander lower membrane cavity through a second commander membrane; a tray is arranged on the second membrane of the commander, and a push rod of the first commander penetrates through a lower membrane cover of the second commander and is fixedly connected with the second membrane of the commander and the second tray of the commander; an adjusting cylinder is mounted on the upper membrane cover of the second commander, an adjusting block is mounted on the adjusting cylinder through threads, and a second commander spring is mounted between the adjusting block and a second commander tray; and a pressure sampling pipe II is arranged on the lower membrane cover of the commander II.

The utility model discloses an adopt three membrane head structures, the commander adopts two membrane heads, has just obtained twice area of contact in other words, under the same thrust, the pressure just can reduce half behind the valve, can reach 0.1kpa at minimum to can reduce the nitrogen gas use amount of storage tank protective layer, and the nitrogen gas pressure of storage tank protective layer behind the valve is lower, and the pressure that chemical material received is little, thereby makes the material more stable, safer, the energy saving, reduce cost, and the valve front-valve rear pressure reduction ratio is very big, and the maximum pressure difference ratio can reach 8000 times; through the arrangement of the double pressure sampling pipes, the air inlet speed is improved, and the reaction sensitivity is increased; through the arrangement of the pressure relief pipe, when the pressure in the upper cavity of the main valve is overlarge, the medium pressure can be discharged to the rear channel of the valve through the pressure relief pipe, and the pressure balance of the upper cavity of the main valve and the lower cavity of the main valve is kept.

Drawings

FIG. 1 is a schematic structural diagram of the present invention;

FIG. 2 is a schematic view of the enlarged partial structure of the present invention;

fig. 3 is a schematic view of the usage state of the present invention.

Illustration of the drawings: 1. a valve body; 2. a valve cover; 3. a support; 4. a main valve diaphragm head; 41. a main valve push rod; 42. a main valve lower membrane cover; 43. a main valve upper membrane cover; 44. a main valve diaphragm; 45. a main valve upper chamber; 46. a lower main valve cavity; 47. a tray; 48. a spring guide post; 49. a spring; 5. a director; 51. a commander valve body; 52. the upper valve cavity of the director; 53. a lower valve cavity of the director; 54. a channel; 55. a commander valve stem; 56. a commander valve core; 57. a director push rod; 58. a flow path; 59. a pressure guiding pipe II; 510. a needle valve; 6. a commander membrane head; 61. a first director membrane; 611. a lower membrane cover of the commander; 612. a diaphragm of the commander; 613. a membrane cover is arranged on the commander; 614. the commander is provided with an upper membrane cavity; 615. a lower diaphragm cavity of the director; 616. a tray of the director; 617. a push rod of the director; 618. connecting blocks; 62. a second commander membrane head; 621. a membrane cover is arranged below the commander II; 622. a second diaphragm of the commander; 623. a membrane cover is arranged on the commander II; 624. a second commander is provided with a membrane cavity; 625. a second pilot device is arranged in the lower diaphragm cavity; 626. a second director tray; 627. an adjusting cylinder; 628. an adjusting block; 629. a commander spring; 63. a pressure sampling pipe I; 64. a pressure sampling pipe II; 7. a pressure relief pipe; 8. a guide sleeve; 9. a valve stem; 10. a valve core; 11. a valve seat; 12. a pre-valve passage; 13. a post-valve channel; 14. a pressure leading pipe I; 15. a pressure reducer.

Detailed Description

The three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve of the present invention will be further described with reference to the accompanying drawings 1-3.

Referring to fig. 1-3, a three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve of the present embodiment includes a valve body 1, a valve cover 2 mounted on the valve body 1, a support 3 mounted on the valve cover 2, a main valve membrane head 4 mounted on the support 3, a commander 5 mounted on the main valve membrane head 4, and a commander membrane head 6 mounted on the commander 5; the device is characterized in that the commander membrane head 6 is divided into a first commander membrane head 61 and a second commander membrane head 62; the first commander membrane head 61 and the second commander membrane head 62 are respectively connected with a first pressure sampling pipe 63 and a second pressure sampling pipe 64; a pressure relief pipe 7 is connected between the main valve membrane head 4 and the valve body 1; through the arrangement of the double membrane heads of the first commander membrane head 61 and the second commander membrane head 62, the double contact area is obtained, the pressure behind the valve can be reduced by half under the same thrust, and the minimum pressure can reach 0.1kpa, so that the nitrogen use amount of a storage tank protective layer can be reduced, the nitrogen pressure of the storage tank protective layer behind the valve is lower, the pressure received by chemical materials is small, so that the materials are more stable and safer, the energy is saved, the cost is reduced, the pressure reduction ratio behind the valve in front of the valve is particularly large, and the maximum pressure difference ratio can reach 8000 times; through the setting of two pressure pipes, improve the admission speed, increase reaction sensitivity.

Further, referring to fig. 1, a guide sleeve 8 is installed between the valve body 1 and the valve cover 2, a valve rod 9 is slidably installed on the guide sleeve 8, one end of the valve rod 9 is provided with a valve core 10, and the other end is connected with a main valve push rod 41; the valve body 1 is also provided with a valve seat 11; the main valve push rod 41 penetrates through the bracket 3 and then is connected with the main valve membrane head 4; the valve body 1 is also provided with a valve front channel 12 and a valve rear channel 13; a pressure guiding pipe I14 is connected between the valve front channel 12 and the commander 5, and a pressure reducer 15 is installed on the pressure guiding pipe I14; through the setting of pressure reducer 15, make the medium in the passageway 12 before the valve get into commander 5 reduce pressure through pressure reducer 15 earlier, avoid the valve preceding pressure too big and lead to the medium to strike commander valve body 51 to produce the noise and cause the damage to commander 5.

Further, referring to fig. 1, the master poppet 4 includes a master lower poppet cover 42 mounted on the support 3, a master upper poppet cover 43 mounted on the master lower poppet cover 42, and a master poppet 44 mounted between the master upper poppet cover 43 and the master lower poppet cover 42, the master poppet 4 being formed with a master upper poppet 45 and a master lower poppet 46 by the master poppet 44; the main valve push rod 41 penetrates through the main valve lower membrane cover 42 and then is fixedly connected with the main valve membrane 44; a tray 47 is arranged on the main valve diaphragm 44, a spring guide column 48 is arranged on the tray 47, and a spring 49 is arranged on the spring guide column 48; the main valve upper membrane cover 43 is connected with a pressure relief pipe 7, and the other end of the pressure relief pipe 7 is connected with the valve rear channel 13; the upper membrane cover 43 of the main valve is provided with a director 5; by the arrangement of the pressure relief pipe 7, when the pressure in the main valve upper chamber 45 is too high, the medium pressure can be directly discharged to the valve rear channel 13 through the pressure relief pipe 7 by the pressure relief pipe 7, and the pressure balance between the main valve upper chamber 45 and the main valve lower chamber 46 is maintained.

Further, referring to fig. 2, the commander 5 includes a commander valve body 51, the commander valve body 51 is provided with a commander upper valve cavity 52 and a commander lower valve cavity 53, a passage 54 is provided between the commander upper valve cavity 52 and the commander lower valve cavity 53, a commander valve rod 55 is slidably mounted on the passage 54, one end of the commander valve rod 55 is connected with a commander valve core 56, and the other end is connected with a commander push rod 57; the commander valve body 51 is also provided with a flow path 58, one end port of the flow path 58 is communicated with the main valve upper cavity 45, the other end of the flow path is connected with a pressure guiding pipe II 59, and the other end of the pressure guiding pipe II 59 is communicated with the main valve lower cavity 46; a needle valve 510 is further mounted on the flow path 58 through threads; a first commander membrane head 61 is arranged on the commander valve body 51; the surface of the commander valve core 56 is also provided with a rubber seal; through the arrangement of the needle valve 510, the opening degree of the needle valve 510 is adjusted through threads, so that the flow passage area on the commander valve body 51 is adjusted, the flow resistance of the needle valve 510 is increased, the gas flowing into the upper main valve cavity 45 is slightly positive pressure, the gas flowing into the lower main valve cavity 46 is relatively high pressure, and the pressure difference is formed between the upper cavity and the lower cavity; by providing a rubber seal on the surface of the commander valve element 56, a tight seal of the commander valve element 56 can be achieved at an extremely low pressure of 0.1 kpa.

Further, referring to fig. 1, the first commander membrane 61 comprises a first commander lower membrane cover 611 mounted on the commander valve body 51, and the first commander membrane 612 and the first commander upper membrane cover 613 are mounted on the first commander lower membrane cover 611; the first director membrane head 61 is provided with a first director membrane cavity 614 and a second director membrane cavity 615 through a first director membrane 612; the first commander upper membrane cover 613 is provided with a first commander tray 616, and the first commander push rod 57 sequentially passes through the first commander lower membrane cover 611, the first commander membrane 612 and the first commander tray 616 and then is connected with a first commander push rod 617; the commander lower membrane cover 611 is connected with a pressure sampling pipe I63; the connecting block 618 is installed on the first commander upper membrane cover 613, and the first commander push rod 617 is connected with the connecting block 618 in a sliding manner; a second commander membrane head 62 is mounted on the connecting block 618; the first director membrane head 61 and the second director membrane head 62 are installed and connected through the arrangement of the connecting block 618; through the setting of the pressure tapping pipe I63, one end is directly connected with the rear of the valve, and the medium behind the valve is directly tapped into a lower diaphragm cavity 615 of the commander for use.

Further, referring to fig. 1, the second commander membrane head 62 comprises a second commander lower membrane cover 621 mounted on the connecting block 618, a second commander membrane 622 mounted on the second commander lower membrane cover 621, and a second commander upper membrane cover 623; the second commander membrane head 62 is provided with a second commander upper membrane cavity 624 and a second commander lower membrane cavity 625 through a second commander membrane 622; a second commander tray 626 is installed on the second commander diaphragm 622, and the first commander push rod 617 penetrates through the second commander lower diaphragm cover 621 and is fixedly connected with the second commander diaphragm 622 and the second commander tray 626; an adjusting cylinder 627 is installed on the upper membrane cover 623 of the second commander, an adjusting block 628 is installed on the adjusting cylinder 627 through threads, and a second commander spring 629 is installed between the adjusting block 628 and the second commander tray 626; a second pressure sampling pipe 64 is arranged on the lower membrane cover 621 of the second commander; through the arrangement of the adjusting cylinder 627, the adjusting block 628 and the commander spring 629, the position of the adjusting block 628 in the adjusting cylinder 627 is adjusted to form extrusion force on the commander spring 629, and the set pressure value is set, and the set pressure value can be adjusted through adjusting the position of the adjusting block 628; through the arrangement of the second pressure tapping pipe 64, the pressure after the valve enters the second lower diaphragm cavity 625 of the commander through the second pressure tapping pipe 64 to be compared with the set pressure value.

Referring to the attached fig. 1-3, the working process of the present invention is:

when the pressure behind the valve is lower than the set value: the second commander diaphragm 622 and the first commander push rod 617 are pushed to move downwards by the acting force of the first commander spring 629, the first commander push rod 617 pushes the first commander diaphragm 612 to move downwards so as to push the first commander push rod 57 to move downwards, the commander push rod 57 drives the commander valve core 56 to move downwards so as to open the passage 54, at this time, the medium in the front valve passage 12 flows through the pressure reducer 15 via the first pressure reducing pipe 14, is reduced in pressure by the pressure reducer 15 and flows into the lower commander valve cavity 53, and flows into the upper commander valve cavity 52 via the passage 54, at this time, the medium flows into the lower main valve cavity 46 via the second pressure reducing pipe 59 on one path, flows into the upper main valve cavity 45 after being throttled by the needle valve 510, and forms a pressure difference between the upper main valve cavity 45 and the lower valve cavity 46 via the flow resistance of the lower needle valve 510, the pressure of the main valve, thereby driving the main valve push rod 41, the valve rod 9 and the valve core 10 to move upwards, opening the medium flow path on the valve body 1 to increase, and further increasing the pressure behind the valve; meanwhile, real-time monitoring is carried out through the first pressure taking pipe 63 and the second pressure taking pipe 64, and when the pressure rises to a set value, the valve core 10 is restored to a closed position;

when the pressure behind the valve is larger than the set value: the pressure after the valve enters a first commander diaphragm cavity 615 and a second commander diaphragm cavity 625 through a first pressure taking pipe 63 and a second pressure taking pipe 64, the first commander diaphragm 612 and the second commander diaphragm 622 are pushed to move upwards, so that a commander spring 629 is compressed, the first commander diaphragm 612 drives a commander push rod 57 to move upwards, and the commander push rod 57 drives a commander valve core 56 to move upwards, so that a channel 54 is closed; at this time, the medium in the front valve passage 12 flows through the pressure reducer 15 through the first pressure-reducing pipe 14, is reduced in pressure by the pressure reducer 15, flows into the lower commander valve chamber 53, the flow path 58 flowing into the upper commander valve chamber 52 is closed, the medium cannot enter the lower main valve chamber 46 through the second pressure-reducing pipe 59, the gas in the lower main valve chamber 46 flows back to the upper commander valve chamber 52 through the second pressure-reducing pipe 59, and flows into the upper main valve chamber 45 through the needle valve, the medium in the upper main valve chamber 45 flows into the valve through the pressure-reducing pipe 7, so that the pressures in the upper main valve chamber 45 and the lower main valve chamber 46 are balanced, and the main valve diaphragm 44 is pushed downward by the acting force of the spring 49, so that the push rod 41 of the main valve, the valve rod 9 and the valve element 10 are pushed.

The scope of the present invention is not limited to the above embodiments and their variations. The present invention is not limited to the above embodiments, and other modifications and substitutions may be made by those skilled in the art.

Claims

1. A three-membrane-head double-pressure-taking ultra-micro-pressure nitrogen seal regulating valve comprises a valve body (1), a valve cover (2) arranged on the valve body (1), a support (3) arranged on the valve cover (2), a main valve membrane head (4) arranged on the support (3), a commander (5) arranged on the main valve membrane head (4) and a commander membrane head (6) arranged on the commander (5); the device is characterized in that the commander membrane head (6) is divided into a commander membrane head I (61) and a commander membrane head II (62); the first commander membrane head (61) and the second commander membrane head (62) are respectively connected with a first pressure sampling pipe (63) and a second pressure sampling pipe (64); and a pressure relief pipe (7) is connected between the main valve membrane head (4) and the valve body (1).

2. The three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve according to claim 1, characterized in that: a guide sleeve (8) is arranged between the valve body (1) and the valve cover (2), a valve rod (9) is slidably arranged on the guide sleeve (8), one end of the valve rod (9) is provided with a valve core (10), and the other end of the valve rod is connected with a main valve push rod (41); the valve body (1) is also provided with a valve seat (11); the main valve push rod (41) penetrates through the bracket (3) and then is connected with the main valve membrane head (4); the valve body (1) is also provided with a front valve channel (12) and a rear valve channel (13); a pressure guiding pipe I (14) is connected between the valve front channel (12) and the commander (5), and a pressure reducer (15) is installed on the pressure guiding pipe I (14).

3. The three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve according to claim 2, characterized in that: the main valve membrane head (4) comprises a main valve lower membrane cover (42) arranged on the support (3), a main valve upper membrane cover (43) arranged on the main valve lower membrane cover (42) and a main valve membrane (44) arranged between the main valve upper membrane cover (43) and the main valve lower membrane cover (42), and the main valve membrane head (4) is formed with a main valve upper cavity (45) and a main valve lower cavity (46) through the main valve membrane (44); the main valve push rod (41) penetrates through the main valve lower membrane cover (42) and then is fixedly connected with the main valve membrane (44); a tray (47) is mounted on the main valve diaphragm (44), a spring guide column (48) is mounted on the tray (47), and a spring (49) is mounted on the spring guide column (48); the upper membrane cover (43) of the main valve is connected with a pressure relief pipe (7), and the other end of the pressure relief pipe (7) is connected with a valve rear channel (13); and a director (5) is arranged on the main valve upper membrane cover (43).

4. The three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve according to claim 3, characterized in that: the pilot valve (5) comprises a pilot valve body (51), an upper pilot valve cavity (52) and a lower pilot valve cavity (53) are arranged on the pilot valve body (51), a channel (54) is arranged between the upper pilot valve cavity (52) and the lower pilot valve cavity (53), a pilot valve rod (55) is slidably mounted on the channel (54), one end of the pilot valve rod (55) is connected with a pilot valve core (56), and the other end of the pilot valve rod is connected with a pilot push rod (57); a flow path (58) is further arranged on the director valve body (51), one end port of the flow path (58) is communicated with the main valve upper cavity (45), the other end of the flow path is connected with a second pressure guiding pipe (59), and the other end of the second pressure guiding pipe (59) is communicated with the main valve lower cavity (46); a needle valve (510) is further mounted on the flow path (58) through threads; a first commander membrane (61) is arranged on the commander valve body (51); the surface of the director valve core (56) is also provided with a rubber seal.

5. The three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve according to claim 4, characterized in that: the first commander membrane head (61) comprises a first commander lower membrane cover (611) arranged on the commander valve body (51), and a first commander membrane (612) and a first commander upper membrane cover (613) are arranged on the first commander lower membrane cover (611); the first director membrane head (61) is provided with a first director membrane cavity (614) and a second director membrane cavity (615) through a first director membrane (612); a first commander membrane cover (613) is provided with a first commander tray (616), and the first commander push rod (57) sequentially passes through the first commander membrane cover (611), the first commander membrane (612) and the first commander tray (616) and then is connected with a first commander push rod (617); a first pressure sampling pipe (63) is connected to the lower membrane cover (611) of the commander; a connecting block (618) is arranged on the first commander membrane cover (613), and a first commander push rod (617) is connected with the connecting block (618) in a sliding way; and a second commander membrane head (62) is arranged on the connecting block (618).

6. The three-membrane-head double-pressure-taking ultra-micro pressure nitrogen seal regulating valve according to claim 5, characterized in that: the second commander membrane head (62) comprises a second commander lower membrane cover (621) arranged on the connecting block (618), a second commander membrane (622) arranged on the second commander lower membrane cover (621) and a second commander upper membrane cover (623); the second commander membrane head (62) is provided with a second commander upper membrane cavity (624) and a second commander lower membrane cavity (625) through a second commander membrane (622); a second commander tray (626) is arranged on the second commander diaphragm (622), and the first commander push rod (617) penetrates through a second commander lower diaphragm cover (621) to be fixedly connected with the second commander diaphragm (622) and the second commander tray (626); an adjusting cylinder (627) is installed on the second commander upper film cover (623), an adjusting block (628) is installed on the adjusting cylinder (627) through threads, and a second commander tray (626) is provided with a second commander spring (629) between the adjusting block (628) and the second commander tray; and a second pressure sampling pipe (64) is arranged on the lower membrane cover (621) of the second commander.