CN220706440U

CN220706440U - Pipeline stop valve

Info

Publication number: CN220706440U
Application number: CN202322477339.8U
Authority: CN
Inventors: 蒋小平; 蒋嘉磊
Original assignee: Shanghai Qiyu Mechanical And Electrical Equipment Co ltd
Current assignee: Shanghai Qiyu Mechanical And Electrical Equipment Co ltd
Priority date: 2023-09-13
Filing date: 2023-09-13
Publication date: 2024-04-02
Anticipated expiration: 2033-09-13

Abstract

The utility model provides a pipeline stop valve which comprises a valve body and a valve core, wherein a liquid inlet and a liquid outlet are respectively arranged at two ends of the valve body, a valve seat is arranged in a valve cavity, a driving unit is arranged at the front end of the valve core, the driving unit drives the valve core to linearly move relative to the valve seat to close or open a valve port between the liquid inlet and the liquid outlet, a diaphragm is arranged between the valve core and the valve seat to form a sealing structure, and the diaphragm is turned over to adapt to relative movement between the valve core and the valve seat when the driving unit drives the valve core to move. A diaphragm is arranged between the valve core and the valve seat to form a sealing structure, and the reliable sealing effect of the valve core relative to the valve seat in the moving process can be ensured through the overturning action of the diaphragm; the diaphragm cannot rub with the valve core and the valve seat, and abrasion is avoided; the valve port is opened and closed in a pneumatic mode, so that the response is rapid, and the quick on-off of the pipeline can be ensured; the whole driving unit is arranged in the pipeline stop valve, and the pipeline stop valve is small in size and beneficial to arrangement of pipelines.

Description

Pipeline stop valve

Technical Field

The utility model relates to the technical field of liquid conveying pipelines, in particular to a pipeline stop valve.

Background

The aircraft fuelling vehicle is the most widely used fuelling device in large and medium-sized airports, and plays a great role in aircraft fuelling guarantee. The fuel delivery pipeline of the aircraft fuelling vehicle is required to be provided with a stop valve so as to realize fuel supply and stop. In order to achieve the purpose of quick on-off, the intelligent oiling system of the aircraft fuelling vehicle needs to adopt a pneumatic control valve to replace a manual valve, the most common pneumatic control valve is a pneumatic ball valve, if the pneumatic ball valve is directly applied to the aircraft fuelling vehicle, a pneumatic actuator needs to be installed due to the structural characteristics of the ball valve, and a valve rod of the pneumatic actuator protrudes to the outside of a valve body, so that the whole stop valve is large in size and unfavorable for pipeline arrangement.

Disclosure of Invention

The utility model aims to provide a pipeline stop valve with small volume and long service life.

In order to achieve the above purpose, the technical scheme adopted by the utility model is as follows: the utility model provides a pipeline stop valve, includes valve body and case, and inlet and liquid outlet are established respectively at the both ends of valve body, are equipped with the disk seat in the valve pocket, and the case front end is provided with drive unit, and drive unit drive case is closed or is opened the valve port between inlet and the liquid outlet for disk seat rectilinear motion, case and disk seat between be provided with the diaphragm and constitute seal structure, the diaphragm takes place the tilting action in order to adapt to relative motion between the two when drive unit drive case moves.

The diaphragm is in a shallow disc shape as a whole, and the section of the diaphragm is in a Z shape, and comprises an outer ring lip edge, an inner ring lip edge and a turnover lip edge between the outer ring lip edge and the inner ring lip edge, wherein the joint of the outer ring lip edge and the turnover lip edge is in rounded transition, and the joint of the inner ring lip edge and the turnover lip edge is in rounded transition.

The radius of the fillet at the joint of the outer ring lip edge and the turnover lip edge is 1-2 mm, and the radius of the fillet at the joint of the inner ring lip edge and the turnover lip edge is 1-2 mm.

The outer ring lip is fixed on the step surface of the proximal end of the valve core through the pressing ring and the bolt/pin, the inner ring lip is clamped between the valve seat and the valve body to form fixed connection, the outer ring lip and the inner ring lip are arranged in parallel, and when the valve core is positioned at the position of closing and opening the valve port, the outer ring lip is respectively positioned at the two axial sides of the inner ring lip.

One side of the inner cavity of the valve body, which is close to the liquid outlet, is provided with a mounting seat, an inclined surface is arranged on the mounting seat, a sealing ring is clamped in the middle of the inclined surface, and the sealing ring is propped against or separated from the conical surface at the rear end of the valve core to close or open a valve port between the liquid inlet and the liquid outlet.

The section of the sealing ring is shaped, the mounting seat is formed by two split bodies, the sealing ring is clamped between the gaps of the two split bodies, and the sealing lip of the sealing ring protrudes out of the inclined plane.

The sealing ring and the two split-type matched side edges of the mounting seat are convexly provided with convex strips, the cross section of a sealing lip of the sealing ring, which is protruded outside the inclined plane, is V-shaped, and the sealing lip is in line contact sealing fit with the conical surface of the rear end of the valve core when being abutted.

The driving unit comprises a valve rod parallel to the axis of the valve body, one end of the valve rod is fixed with the valve core, the other end of the valve rod protrudes to the valve seat inner cavity and axially moves with the valve seat, the valve seat inner cavity and the valve body inner cavity are in butt joint to form a containing cavity, a pressure spring is arranged in the containing cavity, the pressure spring provides elasticity to drive the valve rod to drive the valve core to close the valve port, an air inlet channel is formed in the valve seat, one end of the air inlet channel is communicated with the containing cavity, the other end of the air inlet channel extends outwards to the outside of the valve body and is communicated with an air source, and compressed air enters the containing cavity from the air inlet channel to overcome the elasticity and the liquid pressure of the pressure spring and drive the valve rod to drive the valve core to open the valve port.

The valve rod is sleeved with a guide seat, a through hole for the valve rod to pass through is formed in the guide seat, the valve rod and the guide seat form fixed and sealed fit, one end of the pressure spring is propped against the guide seat, the other end of the pressure spring is propped against the inner wall of the valve body forming the accommodating cavity, and the outer wall of the guide seat and the inner wall of the accommodating cavity form guide and sealed fit.

Under the valve port closing state, the air inlet passage outlet and the pressure spring are positioned at two sides of the guide seat, the valve body is also provided with an exhaust passage, one end of the exhaust passage is communicated with the accommodating cavity, the other end of the exhaust passage extends outwards to the outside of the valve body, under the valve port opening state, the air outlet passage outlet and the pressure spring are positioned at the same side of the guide seat, and the air inlet passage and the exhaust passage are always positioned at two sides of the guide seat.

The guide seat is integrally cylindrical, an annular cavity with an opening facing the pressure spring is formed in the guide seat, the inner diameter and the outer diameter of the annular cavity are matched with the inner diameter and the outer diameter of the pressure spring, the end part of the pressure spring is abutted to the bottom wall of the annular cavity, and a groove matched with the other end of the pressure spring is formed in the valve body.

The inner wall of the valve seat is provided with a step hole, a guide sleeve is arranged in the step hole, an annular groove is formed in the outer wall of the guide seat corresponding to the guide sleeve, a sealing ring is arranged in the annular groove, and an outlet of the air inlet channel is formed in the inner wall of the valve seat, close to one side of the liquid outlet, of the guide sleeve.

One side of the valve seat facing the liquid outlet is convexly provided with a cone, a through hole for the valve rod to pass through is axially formed in the cone, and a sealing sleeve is also arranged in the through hole.

The sealing sleeves are arranged 2 in the axial direction of the valve rod at intervals, the sealing sleeves are clamped in annular grooves formed in the cone, the cross sections of the sealing sleeves are in a shape of 'E', and openings of the two sealing sleeves are arranged in a deviating mode.

In the scheme, the device at least has the following beneficial effects:

1. a diaphragm is arranged between the valve core and the valve seat to form a sealing structure, and the reliable sealing effect of the valve core relative to the valve seat in the moving process can be ensured through the overturning action of the diaphragm;

2. the diaphragm cannot rub with the valve core and the valve seat, so that abrasion is avoided, and the service life of the whole pipeline stop valve is ensured;

3. the valve port is opened and closed in a pneumatic mode, so that the response is rapid, and the quick on-off of the pipeline can be ensured;

4. the whole driving unit is arranged in the pipeline stop valve, and the pipeline stop valve is small in size and beneficial to arrangement of pipelines.

Drawings

FIG. 1 is a schematic view of the overall structure of a pipe shut-off valve in a closed state;

FIG. 2 is a schematic view of the whole structure of the pipe stop valve in an open state;

FIGS. 3 and 4 are cross-sectional views of the pipe shut-off valve in a closed state;

fig. 5 and 6 are sectional views of the pipe shut-off valve in an opened state;

FIG. 7 is a schematic view of the diaphragm in a closed state;

fig. 8 is a schematic structural view of the membrane in an open state.

Description of the embodiments

For ease of illustration, the orientation is first defined, "front", "upstream" refers to the side adjacent the inlet and "rear", "downstream" refers to the side adjacent the outlet, as discussed in further detail below in connection with FIGS. 1-8.

The utility model provides a pipeline stop valve, includes valve body 10 and case 20, and inlet 11 and liquid outlet 12 are established respectively at the both ends of valve body 10, are equipped with disk seat 30 in the valve pocket A, and case 20 front end is provided with drive unit 40, and drive unit 40 drive case 20 is closed or is opened the valve port 15 between inlet 11 and the liquid outlet 12 for disk seat 30 rectilinear motion, case 20 and disk seat 30 between be provided with diaphragm 50 and constitute seal structure, diaphragm 50 takes place the tilting action in order to adapt to relative motion between the two when drive unit 40 drive case 20 moves.

The working process of the pipeline stop valve is as follows: the pipeline stop valve is arranged in the middle of the pipeline and is used for stopping and conducting liquid in the pipeline, under normal conditions, the valve core 20 compresses the valve body 10 under the action of the driving force of the driving unit 40 and the pressure of the liquid, the valve port 15 between the liquid inlet 11 and the liquid outlet 12 is closed, and the liquid cannot pass through the valve port 15, so that the purpose of stopping the pipeline is achieved; the driving unit 40 provides power to drive the valve core 20 to move linearly relative to the valve seat 30 and to leave the valve body 10, at this time, the valve port 15 between the liquid inlet 11 and the liquid outlet 12 is opened, and liquid enters from the liquid inlet 11 and flows out from the liquid outlet 12.

Because the valve seat 30 is fixed relative to the valve body 10, the valve core 20 is movably arranged and moves linearly relative to the valve seat 30, in order to prevent liquid from passing through a gap between the valve core 20 and the valve seat 30, a diaphragm 50 is arranged between the valve core 20 and the valve seat 30 to form a sealing structure, the reliable sealing effect of the valve core 20 relative to the valve seat 30 can be ensured in the moving process through the overturning action of the diaphragm 50, the diaphragm 50 does not rub with the valve core 20 and the valve seat 30, no abrasion is caused, and the service life of the whole pipeline stop valve is ensured.

As a preferred scheme of the utility model, the diaphragm 50 is in a tray shape as a whole, has a Z-shaped cross section and comprises an outer ring lip 51, an inner ring lip 52 and a turnover lip 53 between the outer ring lip 51 and the inner ring lip 52, and the joint of the outer ring lip 51 and the turnover lip 53 is in rounded transition. The arrangement of the round corners ensures the smoothness of the overturning action of the diaphragm 50 and can prevent the diaphragm 50 from cracking due to stress concentration.

The preparation method is characterized by comprising the following steps of: the fillet radius at the junction of the outer ring lip 51 and the flip lip 53 is 1mm to 2mm, and the fillet radius at the junction of the inner ring lip 52 and the flip lip 53 is 1mm to 2mm, in which state the sealing effect and the service life of the diaphragm 50 can be simultaneously optimized.

The outer ring lip 51 is fixed on the step surface of the proximal end of the valve core 20 through a pressing ring and a bolt/pin, the inner ring lip 52 is clamped between the valve seat 30 and the valve body 10 to form fixed connection, the outer ring lip 51 and the inner ring lip 52 are arranged in parallel, and when the valve core 20 is positioned at the position of closing and opening the valve port 15, the outer ring lip 51 is respectively positioned at two axial sides of the inner ring lip 52. As shown in fig. 7 and 8, a plurality of mounting holes 521 are formed in the inner ring lip 52 at intervals along the circumferential direction thereof, and bolts pass through the mounting holes 521 to fix the inner ring lip 52 to the valve body 10, and the outer ring lip 51 is fixed to the valve body 20 by a clamping ring and bolts/pins, thereby securing the inner ring lip 52 reliably.

In order to ensure the tightness of the valve port 15 during closing, a sealing ring 14 is required to be arranged, a mounting seat 13 is arranged on one side, close to the liquid outlet 12, of the inner cavity of the valve body 10 for mounting the sealing ring 14, an inclined surface 131 is arranged on the mounting seat 13, the sealing ring 14 is clamped in the middle of the inclined surface 131, and the sealing ring 14 is propped against or separated from a conical surface 21 at the rear end of the valve core 20 so as to close or open the valve port 15 between the liquid inlet 11 and the liquid outlet 12.

In order to install the seal ring 14, the section of the seal ring 14 is shaped, the installation seat 13 is formed by two split bodies, the seal ring 14 is clamped between the two split gaps, and the seal lip 141 of the seal ring 14 protrudes out of the inclined plane 131. The inclined surface 131 is provided so as to avoid the conical surface 21, so that the conical surface 21 can abut against the seal lip 141.

The stability of sealing washer 14 self position is the basic premise of guaranteeing valve port 15 leakproofness, and sealing washer 14 and two components of a whole that can function independently complex side protruding extension of mount pad 13 are provided with sand grip 142, and sand grip 142 has promoted the sealed effect between two components of a whole that can function independently of sealing washer and mount pad 13 for sealing washer 14 and mount pad 13 seal reliably, and sealing washer 14 protrusion outside inclined plane 131's sealing lip 141 cross-section is the V-arrangement, and sealing lip 141 constitutes line contact sealing cooperation when the circular conical surface 21 butt of case 20 rear end, and sealed effect is good.

As shown in fig. 3-6, the driving unit 40 includes a valve rod 41 parallel to the axis of the valve body 10, one end of the valve rod 41 is fixed with the valve core 20, the other end protrudes to the inner cavity of the valve seat 30 and moves axially with the valve seat 30, the inner cavity of the valve seat 30 is in butt joint with the inner cavity of the valve body 10 to form a containing cavity B, a compression spring 42 is arranged in the containing cavity B, the compression spring 42 provides elastic force to drive the valve rod 41 to drive the valve core 20 to close the valve port 15, an air inlet channel a is formed on the valve seat 30, one end of the air inlet channel a is communicated with the containing cavity B, the other end of the air inlet channel extends outwards to the outside of the valve body 10 and is communicated with an air source, and compressed air enters the containing cavity B from the air inlet channel a to overcome the elastic force and the liquid pressure of the compression spring 42 and drive the valve rod 41 to drive the valve core 20 to open the valve port 15. In a natural state, the elastic force of the pressure spring 42 and the pressure of the liquid drive the valve rod 41 to move leftwards in the drawing, and the valve rod 41 drives the valve core 20 to move leftwards so that the conical surface 21 on the valve core is abutted against the sealing lip 141, thereby sealing the valve port 15 and blocking a circulation passage; compressed gas is introduced into the air inlet passage a, the compressed gas enters the accommodating cavity B from the air inlet passage a, overcomes the elasticity and the liquid pressure of the pressure spring 42, drives the valve rod 41 to drive the valve core 20 to open the valve port 15, and responds rapidly. Most importantly, the whole driving unit 40 is arranged inside the pipeline stop valve, and the whole pipeline stop valve is small in size and beneficial to the arrangement of pipelines.

In order to ensure that the valve rod 41 can drive the valve core 20 to linearly move along the axis of the valve body, a guide seat 43 is sleeved on the valve rod 41, a through hole for the valve rod 41 to pass through is formed in the guide seat 43, the valve rod 41 and the guide seat 43 form fixed and sealed fit, one end of the pressure spring 42 abuts against the guide seat 43, the other end abuts against the inner wall of the valve body 10 forming the accommodating cavity B, and the outer wall of the guide seat 43 and the inner wall of the accommodating cavity B form guide and sealed fit. The guide seat 43 and the inner wall of the accommodating cavity B form guide and sealing fit, so that on one hand, the linear motion of the valve rod 41 can be ensured, the linear motion of the valve core 20 is stable, and on the other hand, the leakage of compressed gas in the accommodating cavity B can be avoided, and the timeliness of opening the valve port 15 is improved.

In the closed state of the valve port 15, the outlet of the air inlet channel a and the pressure spring 42 are located at two sides of the guide seat 43, because in the closed state of the valve port 15, the guide seat 43 is located at the leftmost position of the accommodating cavity B, and at this time, the outlet of the air inlet channel a and the pressure spring 42 are located at two sides of the guide seat 43, so that in any state, the outlet of the air inlet channel a and the pressure spring 42 can be ensured to be located at two sides of the guide seat 43, and when compressed air is introduced into the accommodating cavity B, the compressed air can drive the guide seat 43 to overcome the elasticity of the pressure spring 42 to move to the right side in the drawing, so as to ensure the open state of the valve port 15. The valve body 10 is further provided with an exhaust passage B, one end of the exhaust passage B is communicated with the accommodating cavity B, the other end of the exhaust passage B extends outwards to the outside of the valve body 10, and in the state that the valve port 15 is opened, an outlet of the exhaust passage B and the pressure spring 42 are positioned on the same side of the guide seat 43, because in the state that the valve port 15 is opened, the guide seat 43 is positioned at the rightmost position of the accommodating cavity B, and at the moment, the outlet of the exhaust passage B and the pressure spring 42 are positioned on the same side of the guide seat 43, in any state, the outlet of the exhaust passage B and the pressure spring 42 are always positioned on the same side of the guide seat 43, so that the right air is discharged. The air inlet passage a and the air outlet passage b are positioned on two sides of the guide seat 43 all the time, and one air inlet and one air outlet are matched with each other.

Specifically, the guide seat 43 is integrally cylindrical, an annular cavity 431 with an opening facing the compression spring 42 is formed in the guide seat, the inner diameter and the outer diameter of the annular cavity 431 are matched with those of the compression spring 42, on one hand, the position of the compression spring 42 can be limited, on the other hand, the movement of the compression spring 42 can be guided, the end part of the compression spring 42 is abutted against the bottom wall of the annular cavity 431, and a groove 16 matched with the other end of the compression spring 42 is formed in the valve body 10.

Further, a step hole is formed in the inner wall of the valve seat 30, a guide sleeve 36 is arranged in the step hole, an annular groove 432 is formed in the outer wall of the guide seat 43 corresponding to the guide sleeve 36, a sealing ring 433 is arranged in the annular groove 432, and an outlet of the air inlet passage a is formed in the inner wall of the valve seat 30, close to the liquid outlet, of the guide sleeve 36. The guide sleeve 36 is usually a copper sleeve, is wear-resistant, and can improve the service life of the whole pipeline stop valve; and at the same time, the smoothness of the linear motion of the guide holder 43 can be ensured.

A cone 33 is arranged on the valve seat 30 in a protruding way towards one side of the liquid outlet 12, a through hole for the valve rod 41 to pass through is formed in the cone 33 along the axial direction of the cone, and a sealing sleeve 34 is also arranged in the through hole. When the valve port 15 is opened, the rear end of the cone 33 abuts against the valve core 20 to limit the valve core 20, so that the valve core 20 is prevented from exceeding the stroke and damaging the diaphragm 50, and parts such as a buffer pad can be arranged on the contact surface of the valve core 20 and the buffer pad, so that the service life is prolonged, and the noise is reduced.

In order to prevent liquid from entering the accommodating cavity B, 2 sealing sleeves 34 are arranged at intervals in the axial direction of the valve rod 41, the sealing sleeves 34 are clamped in annular grooves 35 formed in the cone 33, the cross section of each sealing sleeve 34 is in a 'delta' shape, and openings of the two sealing sleeves 34 are arranged away from each other. The left sealing sleeve 34 is deformed under the pressure of liquid, the opening is enlarged, and the sealing sleeve tightly clings to the valve rod 41 and the annular groove 35, so that the liquid is prevented from passing through; the sealing sleeve 34 on the right side is subjected to the pressure of compressed air in the accommodating cavity B, the opening is enlarged, and the sealing sleeve is tightly attached to the valve rod 41 and the annular groove 35, so that the gas is prevented from passing through; thereby ensuring the sealability of the receiving chamber B.

Claims

1. The utility model provides a pipeline stop valve, includes valve body (10) and case (20), and inlet (11) and liquid outlet (12) establish respectively in the both ends of valve body (10), are equipped with disk seat (30) in valve pocket (A), case (20) front end is provided with drive unit (40), and drive unit (40) drive case (20) are closed or are opened valve port (15) between inlet (11) and liquid outlet (12) for disk seat (30) rectilinear motion, its characterized in that: a diaphragm (50) is arranged between the valve core (20) and the valve seat (30) to form a sealing structure, and when the driving unit (40) drives the valve core (20) to move, the diaphragm (50) performs overturning action to adapt to relative movement between the valve core and the valve seat.

2. The pipe shut-off valve of claim 1, wherein: the diaphragm (50) is integrally in a shallow disc shape, and the section of the diaphragm is Z-shaped, and comprises an outer ring lip edge (51), an inner ring lip edge (52) and a turnover lip edge (53) between the outer ring lip edge and the inner ring lip edge, wherein the joint of the outer ring lip edge (51) and the turnover lip edge (53) is in rounded transition, and the joint of the inner ring lip edge (52) and the turnover lip edge (53) is in rounded transition.

3. The pipe shut-off valve of claim 2, wherein: the fillet radius of the joint of the outer ring lip (51) and the turning lip (53) is 1-2 mm, and the fillet radius of the joint of the inner ring lip (52) and the turning lip (53) is 1-2 mm.

4. The pipe shut-off valve of claim 2, wherein: the outer ring lip edge (51) is fixed on the step surface of the proximal end of the valve core (20) through a pressing ring and a bolt/pin, the inner ring lip edge (52) is clamped between the valve seat (30) and the valve body (10) to form fixed connection, the outer ring lip edge (51) and the inner ring lip edge (52) are arranged in parallel, and when the valve core (20) is positioned at the position of closing and opening the valve port (15), the outer ring lip edge (51) is respectively positioned at two axial sides of the inner ring lip edge (52).

5. The pipe shut-off valve of claim 1, wherein: one side of an inner cavity of the valve body (10) close to the liquid outlet (12) is provided with a mounting seat (13), an inclined surface (131) is arranged on the mounting seat (13), a sealing ring (14) is clamped in the middle of the inclined surface (131), and the sealing ring (14) is propped against or separated from a conical surface (21) at the rear end of the valve core (20) to close or open a valve port (15) between the liquid inlet (11) and the liquid outlet (12).

6. The pipe shut-off valve of claim 5, wherein: the section of the sealing ring (14) is in a special shape, the mounting seat (13) is formed by two split bodies, the sealing ring (14) is clamped between the two split gaps, and the sealing lip (141) of the sealing ring (14) protrudes out of the inclined plane (131).

7. The pipe shut-off valve of claim 6, wherein: the sealing ring (14) and the two split-type matched side edges of the mounting seat (13) are convexly provided with convex strips (142), the cross section of a sealing lip (141) of the sealing ring (14) protruding out of the inclined surface (131) is V-shaped, and the sealing lip (141) forms line contact sealing fit when being abutted with a conical surface (21) at the rear end of the valve core (20).

8. The pipe shut-off valve of claim 1, wherein: the driving unit (40) comprises a valve rod (41) parallel to the axis of the valve body (10), one end of the valve rod (41) is fixed with the valve core (20), the other end of the valve rod (41) protrudes to the inner cavity of the valve seat (30) and axially moves with the valve seat (30), the inner cavity of the valve seat (30) is in butt joint with the inner cavity of the valve body (10) to form a containing cavity (B), a pressure spring (42) is arranged in the containing cavity (B), the pressure spring (42) provides elasticity to drive the valve rod (41) to drive the valve core (20) to close the valve port (15), an air inlet channel (a) is formed in the valve seat (30), one end of the air inlet channel (a) is communicated with the containing cavity (B), the other end of the air inlet channel (a) extends outwards to the outside of the valve body (10) and is communicated with an air source, and compressed air enters the containing cavity (B) from the air inlet channel (a) to overcome the elasticity and the liquid pressure of the pressure spring (42) and drive the valve rod (41) to drive the valve core (20) to open the valve port (15).

9. The pipe shut-off valve of claim 8, wherein: the valve rod (41) is sleeved with a guide seat (43), a through hole for the valve rod (41) to pass through is formed in the guide seat (43), the valve rod (41) and the guide seat (43) form fixed and sealed fit, one end of a pressure spring (42) abuts against the guide seat (43), the other end abuts against the inner wall of the valve body (10) forming the accommodating cavity (B), and the outer wall of the guide seat (43) and the inner wall of the accommodating cavity (B) form guide and sealed fit.

10. The pipe shut-off valve of claim 8, wherein: in the closed state of the valve port (15), the outlet of the air inlet channel (a) and the pressure spring (42) are positioned at two sides of the guide seat (43); an exhaust passage (B) is further formed in the valve body (10), one end of the exhaust passage (B) is communicated with the accommodating cavity (B), the other end of the exhaust passage (B) extends outwards to the outside of the valve body (10), and in the valve port (15) opening state, an outlet of the exhaust passage (B) and the pressure spring (42) are located on the same side of the guide seat (43), and the air inlet passage (a) and the exhaust passage (B) are always located on two sides of the guide seat (43).

11. The pipe shut-off valve of claim 9, wherein: the guide seat (43) is integrally cylindrical, an annular cavity (431) with an opening facing the pressure spring (42) is formed in the guide seat, the inner diameter and the outer diameter of the annular cavity (431) are matched with those of the pressure spring (42), the end part of the pressure spring (42) is abutted to the bottom wall of the annular cavity (431), and a groove (16) matched with the other end of the pressure spring (42) is formed in the valve body (10).

12. The pipe shut-off valve of claim 9, wherein: the inner wall of the valve seat (30) is provided with a step hole, a guide sleeve (36) is arranged in the step hole, an annular groove (432) is formed in the outer wall of the guide seat (43) corresponding to the guide sleeve (36), a sealing ring (433) is arranged in the annular groove (432), and an outlet of the air inlet channel (a) is formed in the inner wall of the valve seat (30) on one side, close to the liquid outlet, of the guide sleeve (36).

13. The pipe shut-off valve of claim 8, wherein: a cone (33) is convexly arranged on one side of the valve seat (30) facing the liquid outlet (12), a through hole for the valve rod (41) to pass through is axially formed in the cone (33), and a sealing sleeve (34) is also arranged in the through hole.

14. The pipe shut-off valve of claim 13, wherein: the sealing sleeves (34) are arranged at 2 axial intervals on the valve rod (41), the sealing sleeves (34) are clamped in annular grooves (35) formed in the cone (33), the cross section of each sealing sleeve (34) is in a 'U' -shape, and openings of the two sealing sleeves (34) are arranged in a deviating mode.