A pipe pressure measuring head and a pipe pressure measuring machine comprising the same

Abstract

The utility model relates to pipe detection technical field discloses a kind of pipe pressure head and including the pipe pressure head of pipe pressure machine.A kind of pipe pressure head, including shell, shell is equipped with cavity and opening, cavity is equipped with sealing plate, sealing plate is equipped with gas transmission through-hole;It further includes fixed limiting plate, pipe holding sealing ring and moving block, pipe holding sealing ring is clamped between fixed limiting plate and sealing plate, fixed limiting plate is equipped with with gas transmission through-hole position corresponding pipe hole, moving block is extruded on sealing plate;Cavity includes power gas storage chamber located at the side of moving block away from fixed limiting plate, extrusion gas transmission passage is arranged in shell, extrusion gas transmission passage is communicated with power gas storage chamber, when pressure measurement, moving block extrudes pipe holding sealing ring, to make pipe holding sealing ring inner diameter reduce and hold tightly pipe material located in its inside, so that pipe holding sealing ring and pipe material sealing connection.Afficient to improve the sealing of pipe end, thereby improve pressure measurement accuracy.

Description

Technical Field

[0001] The utility model relates to the technical field of pipe material detection, in particular to a pipe pressure measuring head and a pipe pressure testing machine comprising the same. Background Art

[0002] Pipe pressure testing machines are used to detect the strength of pipe materials and check whether the pipes have cracks, air leakage holes and the like. In the existing pipe pressure testing machine, both ends of the pipe are sealed during detection, then the pipe is sent into water, and finally gas is delivered into the pipe through an external gas delivery device. The air tightness of the pipe is judged by observing whether there are bubbles. When the air pressure inside the pipe reaches a set value, the air pressure inside the pipe is maintained stable, and after a period of observation, the pipe is qualified if no bubbles are generated.

[0003] In current pipe pressure testing machines, the pressure measuring head generally seals the end of the pipe by pressing against the end face of the pipe — a pressing plate is tightly pressed on the end face of the pipe, so that liquid cannot flow into the interior of the pipe from between the pressing plate and the end face of the pipe. However, the pressure bearing capacity of the pressure measuring head adopting this sealing method generally does not exceed 1.5 MPa. If the pressure exceeds 1.5 MPa, the gas inside the pipe is prone to leak from between the pressing plate and the end face of the pipe, resulting in inaccurate test results. Contents of the Utility Model

[0004] The main objective of the utility model is to propose a pipe pressure measuring head, aiming to solve the technical problem of insufficient sealing capacity of pipe pressure measuring heads in the prior art.

[0005] To achieve the above objective, the utility model proposes a pipe pressure measuring head, which comprises a housing, wherein a cavity and an opening communicated with the cavity are arranged in the housing; a sealing plate for abutting against and mutually squeezing the end face of a pipe during pressure measurement is arranged in the cavity, and the sealing plate is provided with a gas delivery through hole. The pipe pressure measuring head further comprises a fixed limiting plate, a pipe holding sealing ring and a moving block. The fixed limiting plate, the pipe holding sealing ring, the sealing plate and the moving block are arranged in a direction from approaching to moving away from the opening. The pipe holding sealing ring is sandwiched between the fixed limiting plate and the sealing plate. The fixed limiting plate is provided with a pipe passing hole corresponding to the position of the gas delivery through hole. Both the sealing plate and the moving block can move axially relative to the housing, and the moving block presses against the sealing plate. The cavity includes a power gas storage cavity located on the side of the moving block away from the fixed limiting plate. A squeezing gas delivery channel for connecting to an external gas delivery device is arranged in the housing, and the squeezing gas delivery channel is communicated with the power gas storage cavity, so that during pressure measurement, the moving block squeezes the pipe holding sealing ring through the sealing plate, to make the inner diameter of the pipe holding sealing ring shrink and hold the pipe located on the inner side thereof tightly, so that the inner side surface of the pipe holding sealing ring is in sealing connection with the outer side wall of the pipe.

[0006] The beneficial effects of this invention are as follows: The pipe pressure testing head is equipped with a pipe-holding sealing ring and a moving block, and also features a corresponding compression gas delivery channel. This ensures a secure connection between the pipe end face and the sealing plate, while simultaneously providing a tight seal by the pipe-holding sealing ring. During pressure testing, even if the gas pressure is too high and leaks between the sealing plate and the pipe end face, the pipe-holding sealing ring will prevent further leakage. This pipe pressure testing head improves the sealing performance of the pipe end, thereby increasing the accuracy of pressure testing. It also allows the pipe pressure testing machine using this head to test a wider range of pipe specifications, expanding its applicability and reducing testing costs.

[0007] Preferably, a first protrusion is provided on the side of the movable block away from the sealing plate. A recess matching the first protrusion is formed on the bottom surface of the cavity. The first protrusion is at least partially located within the recess. A first sealing ring is engaged between the outer wall of the first protrusion and the inner wall of the recess. A second sealing ring is engaged between the movable block and the inner wall of the cavity. An annular stepped surface is formed at the junction of the outer wall of the first protrusion and the outer wall of the movable block. The first sealing ring, the inner wall of the recess, the bottom surface of the cavity, the inner wall of the cavity, the second sealing ring, the outer wall of the movable block, the annular stepped surface, and the outer wall of the first protrusion enclose a power air storage cavity. The outlet of the extrusion air supply channel is located on the bottom surface of the cavity, and the inlet of the extrusion air supply channel is located on the outer wall of the housing. The first protrusion and the recess provide guidance when the movable block moves, ensuring that the movable block does not deviate excessively.

[0008] Preferably, the pipe pressure testing head is provided with a pressure testing gas supply channel, which includes a first pressure testing gas supply channel, a transition cavity, and a second pressure testing gas supply channel connected in sequence. The first pressure testing gas supply channel extends from the outer wall of the shell to the bottom surface of the recess, and the second pressure testing gas supply channel passes through the moving block and the first protrusion and connects to the gas supply through hole. The first sealing ring, the outer wall of the first protrusion, the inner wall of the recess, and the bottom surface of the recess enclose the transition cavity. The transition cavity ensures the continuity and sealing of the pressure testing gas supply channel while the moving block squeezes the sealing plate.

[0009] Preferably, the pipe pressure testing head further includes a pressure testing sleeve, which is detachably connected to the housing and at least partially disposed within the cavity. A fixing limiting plate, a pipe-holding sealing ring, and a sealing plate are disposed within the pressure testing sleeve. A limiting structure is provided on the outer side wall of the pressure testing sleeve and / or the inner side wall of the cavity to restrict the axial relative movement between the pressure testing sleeve and the housing, which helps to expand the applicability of the pipe pressure testing head and reduce the pressure testing cost.

[0010] Preferably, a second protrusion is provided on the side of the moving block near the sealing plate. The second protrusion extends into the inside of the pressure measuring sleeve and squeezes the sealing plate. A third sealing ring is engaged between the outer wall of the second protrusion and the inner wall of the pressure measuring sleeve. The moving block is located between the inner end face of the pressure measuring sleeve and the bottom surface of the cavity and can move axially between the inner end face of the pressure measuring sleeve and the bottom surface of the cavity. This is beneficial to improving the efficiency and accuracy of the pressure measuring gas delivery and ensuring the pressure measuring effect.

[0011] Preferably, the end of the pressure testing sleeve away from the moving block protrudes from the opening and is provided with a guide structure. The guide structure is provided with a guide hole, which is directly opposite to the pipe hole. The diameter of the guide hole gradually decreases in the direction from away from to close to the pipe hole. The guide hole is used to guide the pipe into the pipe hole, which helps to improve the smoothness of the pressure testing process and improve the fault tolerance of the pipe pressure testing machine.

[0012] Preferably, the limiting structure includes an external thread on the outer wall of the pressure measuring sleeve and an internal thread on the inner wall of the cavity. The pressure measuring sleeve is detachably connected to the housing through the external and internal threads and can be fixed relative to the housing in the axial direction, which is beneficial to improving the installation efficiency of the pipe pressure measuring head and extending its service life.

[0013] Preferably, the housing is also provided with an exhaust hole for connecting the cavity, and the exhaust hole is directly opposite the internal thread, which helps to ensure that the pressure measuring sleeve is properly connected to the housing and reduces the difficulty of disassembly and assembly.

[0014] This utility model also discloses a pipe pressure testing machine, including the above-mentioned pipe pressure testing head.

[0015] Preferably, the pipe pressure testing machine includes a gas supply device and at least two pipe pressure testing heads arranged opposite each other, and the gas supply device is connected to the extrusion gas supply channel. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the pipe pressure testing head in an embodiment of this utility model; Figure 2 This is a side view of the pipe pressure measuring head in an embodiment of this utility model; Figure 3 for Figure 2 AA section view in the middle; Figure 4 This is a schematic diagram of the shell structure in an embodiment of the present utility model; Figure 5 This is an exploded view of the pipe pressure testing head in this embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of the movable block, the first protrusion, and the second protrusion in an embodiment of this utility model.

[0018] In the attached diagram: 1-shell, 11-exhaust port, 12-cavity, 121-opening, 122-recess, 123-power air storage chamber, 124-transition chamber, 13-internal thread, 2-moving block, 21-first protrusion, 22-second protrusion, 23-first sealing ring, 24-second sealing ring, 25-third sealing ring, 26-annular stepped surface, 3-sealing plate, 31-air supply through hole, 4-pipe-holding sealing ring, 5-guide structure, 51-guide hole, 6-compression air supply channel, 7-pressure measuring air supply channel, 71-first pressure measuring air supply channel, 72-second pressure measuring air supply channel, 8-pressure measuring sleeve, 81-fixed limiting plate, 811-through pipe hole, 82-external thread, 9-limiting structure.

[0019] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0020] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0021] It should be noted that if the embodiments of this utility model involve directional indicators, such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this utility model involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this utility model.

[0023] like Figures 1 to 6 As shown, a pipe pressure testing head includes a housing 1, with a cavity 12 and an opening 121 connecting the cavity 12. A sealing plate 3 is provided within the cavity 12 for contacting and pressing against the pipe end face during pressure testing. The sealing plate 3 has an air inlet 31. The head also includes a fixed limiting plate 81, a pipe-holding sealing ring 4, and a moving block 2. The fixed limiting plate 81, the pipe-holding sealing ring 4, the sealing plate 3, and the moving block 2 are arranged in a direction from near to far from the opening 121. The pipe-holding sealing ring 4 is sandwiched between the fixed limiting plate 81 and the sealing plate 3. The fixed limiting plate 81 has a position corresponding to the air inlet 31. The corresponding through-hole 811, the sealing plate 3 and the moving block 2 can both move axially relative to the housing 1 and the moving block 2 is pressed against the sealing plate 3; the cavity 12 includes a power air storage cavity 123 located on the side of the moving block 2 away from the fixed limiting plate 81, and the housing 1 is provided with a compression air supply channel 6 for connecting to an external air supply device. The compression air supply channel 6 is connected to the power air storage cavity 123, so that when the pressure is measured, the moving block 2 compresses the pipe-holding sealing ring 4 through the sealing plate 3, so that the inner diameter of the pipe-holding sealing ring 4 is reduced and it grips the pipe located inside it, so that the inner side of the pipe-holding sealing ring 4 is sealed to the outer side wall of the pipe.

[0024] In this embodiment, the pipe pressure testing head is equipped with a pipe-holding sealing ring 4 and a moving block 2, and also has a corresponding compression gas delivery channel 6. This ensures that while the end face of the pipe is sealed to the sealing plate 3, the pipe-holding sealing ring 4 also provides a tight seal around the pipe. During pressure testing, even if the gas pressure is too high and leaks between the sealing plate 3 and the end face of the pipe, it will be blocked by the pipe-holding sealing ring 4, preventing further leakage. This pipe pressure testing head improves the sealing performance of the pipe end, thereby increasing the accuracy of pressure testing. It also allows the pipe pressure testing machine using this head to test more pipes of different specifications, expanding its applicability and reducing testing costs.

[0025] In some specific embodiments, reference is made to Figure 3 , Figure 4 and Figure 6A first protrusion 21 is provided on the side of the movable block 2 away from the sealing plate 3. A recess 122 matching the first protrusion 21 is formed on the bottom surface of the cavity 12. The first protrusion 21 is at least partially located in the recess 122. A first sealing ring 23 is engaged between the outer wall of the first protrusion 21 and the inner wall of the recess 122. A second sealing ring 24 is engaged between the movable block 2 and the inner wall of the cavity 12. An annular step surface 26 is formed at the junction of the outer wall of the first protrusion 21 and the outer wall of the movable block 2. The first sealing ring 23, the inner wall of the recess 122, the bottom surface of the cavity 12, the inner wall of the cavity 12, the second sealing ring 24, the outer wall of the movable block 2, the annular step surface 26, and the outer wall of the first protrusion 21 enclose to form a power storage chamber 123. The outlet of the extrusion gas transmission channel 6 is located on the bottom surface of the cavity 12, and the inlet of the extrusion gas transmission channel 6 is located on the outer wall of the housing 1.

[0026] The bottom surface of cavity 12 refers to the surface opposite to opening 121. The first protrusion 21 and recess 122 provide guidance during the movement of the moving block 2, ensuring it does not deviate excessively. The first sealing ring 23, the inner wall of the recess 122, the bottom surface of cavity 12, the inner wall of cavity 12, the second sealing ring 24, the outer wall of the moving block 2, the annular step surface 26, and the outer wall of the first protrusion 21 enclose the power storage chamber 123. The outlet of the compression gas delivery channel 6 is also connected to the power storage chamber 123. During pressure measurement, the gas delivery device delivers gas to the power storage chamber 123 through the compression gas delivery channel 6, causing the power storage chamber 123 to enlarge—specifically, the distance between the moving block 2 and the bottom surface of cavity 12 increases. This moves the moving block 2 closer to the sealing plate 3, further compressing the sealing plate 3, causing the pipe-holding sealing ring 4 to be deformed and its inner diameter to decrease. The power storage chamber 123 is an annular cavity. After the gas supply equipment supplies gas to it, the gas fills the annular cavity and uniformly pushes the moving block 2 to move.

[0027] The length of the first protrusion 21, the depth of the recess 122, and the position of the first sealing ring 23 need to be set reasonably so that during pressure testing, no matter where the moving block 2 is moved, the first protrusion 21 is at least partially located in the recess 122, and the first sealing ring 23 is always stuck between the outer side wall of the first protrusion 21 and the inner side wall of the recess 122 to ensure the sealing of the power storage chamber 123.

[0028] In some other embodiments, a first protrusion 21 is disposed on the bottom surface of the cavity 12, and a recess 122 is disposed on the side of the movable block 2 away from the sealing plate 3. A first sealing ring 23 is engaged between the outer side wall of the first protrusion 21 and the inner side wall of the recess 122. Any configuration that forms a power storage cavity 123 is acceptable.

[0029] In some specific embodiments, reference is made to Figure 3The pipe pressure testing head is provided with a pressure testing gas supply channel 7. The pressure testing gas supply channel 7 includes a first pressure testing gas supply channel 71, a transition cavity 124 and a second pressure testing gas supply channel 72 connected in sequence. The first pressure testing gas supply channel 71 extends from the outer side wall of the shell 1 to the bottom surface of the pit 122. The second pressure testing gas supply channel 72 passes through the moving block 2 and the first protrusion 21 and connects to the gas supply through hole 31. The first sealing ring 23, the outer side wall of the first protrusion 21, the inner side wall of the pit 122 and the bottom surface of the pit 122 enclose the transition cavity 124.

[0030] In existing pipe pressure testing heads, since there is no structure that requires movement and air passage like the moving block 2 in this embodiment, the internal pressure testing and air supply channel 7 is fixed and does not require additional sealing treatment.

[0031] In this embodiment, a movable block 2 is provided. The movable block 2 not only needs to compress the sealing plate 3, but also needs to conduct the pressure-measuring gas. Therefore, the second pressure-measuring gas delivery channel 72 needs to connect the movable block 2 and the first protrusion 21. Since the movable block 2 is movable, the distance between the first pressure-measuring gas delivery channel 71 and the second pressure-measuring gas delivery channel 72 will change. Therefore, a transition cavity 124 needs to be provided between the first pressure-measuring gas delivery channel 71 and the second pressure-measuring gas delivery channel 72 to ensure the sealing of the pressure-measuring gas delivery channel 7. The transition cavity 124 ensures the continuity and sealing of the pressure-measuring gas delivery channel 7 while the movable block 2 compresses the sealing plate 3, ensuring the normal operation of the pipe pressure measuring head and enriching the functionality of the pipe pressure measuring head.

[0032] In some specific embodiments, reference is made to Figure 3 and Figure 5 The pipe pressure testing head also includes a pressure testing sleeve 8, which is detachably connected to the housing 1 and is at least partially located in the cavity 12. A fixed limiting plate 81, a pipe-holding sealing ring 4, and a sealing plate 3 are located inside the pressure testing sleeve 8. A limiting structure 9 is provided on the outer side wall of the pressure testing sleeve 8 and / or the inner side wall of the cavity 12 to restrict the axial relative movement between the pressure testing sleeve 8 and the housing 1.

[0033] The fixed limiting plate 81, the pipe-holding sealing ring 4, and the sealing plate 3 are located inside the pressure testing sleeve 8, and the pressure testing sleeve 8 is detachably connected to the housing 1. This arrangement allows the pressure testing sleeve 8 to be easily removed and the pipe-holding sealing ring 4 to be replaced according to different outer diameters of the pipe, which helps to expand the applicability of the pipe pressure testing head and reduce the pressure testing cost.

[0034] The limiting structure 9 is designed to ensure that the fixed limiting plate 81 will not move axially during the pressure test, so as to better withstand the extrusion force from the pipe-holding sealing ring 4, and ensure that the deformation of the pipe-holding sealing ring 4 is sufficient to hold the pipe tightly when it is squeezed by the sealing plate 3, thus ensuring the sealing performance.

[0035] In some specific embodiments, reference is made to Figure 3 and Figure 6 The moving block 2 has a second protrusion 22 on the side near the sealing plate 3. The second protrusion 22 extends into the inside of the pressure measuring sleeve 8 and squeezes the sealing plate 3. A third sealing ring 25 is engaged between the outer wall of the second protrusion 22 and the inner wall of the pressure measuring sleeve 8. The moving block 2 is located between the inner end face of the pressure measuring sleeve 8 and the bottom surface of the cavity 12 and can move axially between the inner end face of the pressure measuring sleeve 8 and the bottom surface of the cavity 12.

[0036] Specifically, the second pressure measuring gas supply channel 72 passes through the first protrusion 21, the movable block 2, and the second protrusion 22.

[0037] The purpose of setting the second protrusion 22 and the third sealing ring 25 is to prevent the pressure measuring gas from leaking out from the gap between the second protrusion 22 and the sealing plate 3, thereby improving the efficiency and accuracy of the pressure measuring gas delivery and ensuring the pressure measuring effect.

[0038] In some specific embodiments, reference is made to Figure 1 and Figure 3 The end of the pressure testing sleeve 8 away from the moving block 2 protrudes from the opening 121 and is provided with a guide structure 5. The guide structure 5 is provided with a guide hole 51, which is directly opposite to the through hole 811. The diameter of the guide hole 51 gradually decreases in the direction from away from to close to the through hole 811. The guide hole 51 is used to guide the pipe into the through hole 811.

[0039] Specifically, the guide hole 51, the through hole 811, the inner hole of the pipe-holding sealing ring 4 (in the non-pressure testing state), the air supply hole 31, and the second pressure testing air supply channel 72 are coaxially arranged. The diameter of the air supply hole 31 is smaller than the diameter of the through hole 811 and the inner hole of the pipe-holding sealing ring 4 in the non-pressure testing state, so that after the pipe extends into the pressure testing sleeve 8 through the through hole 811, its end face can directly abut against the sealing plate 3. During the pressure testing process of the pipe pressure testing machine, it is necessary to move the pipe pressure testing head closer to the pipe so that the end of the pipe extends into the pressure testing sleeve 8. However, the actual placement position of the pipe may be deviated. At this time, the guide structure 5 can be used to guide the end of the pipe into the pressure testing sleeve 8. The setting of the guide structure 5 helps to improve the smoothness of the pressure testing process and improve the fault tolerance of the pipe pressure testing machine.

[0040] In some specific embodiments, reference is made to Figures 3 to 5 The limiting structure 9 includes an external thread 82 on the outer side wall of the pressure measuring sleeve 8 and an internal thread 13 on the inner side wall of the cavity 12. The pressure measuring sleeve 8 is detachably connected to the housing 1 through the external thread 82 and the internal thread 13, and can be fixed relative to the housing 1 in the axial direction.

[0041] The pressure testing sleeve 8 is detachably connected to the housing 1 via external thread 82 and internal thread 13. This is a convenient, reliable and internally applicable detachable connection method, which helps to improve the installation efficiency of the pipe pressure testing head and extend its service life.

[0042] In some specific embodiments, reference is made to Figure 4 The housing 1 is also provided with an exhaust hole 11 that connects to the cavity 12, and the exhaust hole 11 is directly opposite the internal thread 13.

[0043] As described above, the movable block 2 is positioned between the inner end face of the pressure-measuring sleeve 8 and the bottom surface of the cavity 12. During pressure measurement, when the power air storage chamber 123 expands, the movable block 2 moves closer to the pressure-measuring sleeve 8, thereby compressing the space between the pressure-measuring sleeve 8 and the movable block 2. If the air pressure in the space between the pressure-measuring sleeve 8 and the movable block 2 is too high, it may cause the external thread 82 on the outer wall of the pressure-measuring sleeve 8 to be pressed more tightly against the internal thread 13 on the inner wall of the cavity 12, making it difficult to remove the pressure-measuring sleeve 8 from the housing 1. In this embodiment, an exhaust port 11 is provided. When the power air storage chamber 123 expands, even if the space between the pressure-measuring sleeve 8 and the movable block 2 shrinks, the gas in this space can be discharged through the exhaust port 11, allowing the internal thread 13 and the external thread 82 to connect normally, reducing the possibility of excessive tightness in the connection. This arrangement helps to ensure a normal connection between the pressure-measuring sleeve 8 and the housing 1, reducing the difficulty of disassembly and assembly.

[0044] This embodiment also discloses a pipe pressure testing machine, including the above-mentioned pipe pressure testing head.

[0045] In some specific embodiments, the pipe pressure testing machine includes a gas delivery device and at least two pipe pressure testing heads arranged opposite each other, and the gas delivery device is connected to the extrusion gas delivery channel 6.

[0046] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A pipe pressure testing head, characterized in that: Includes a housing (1), the housing (1) having a cavity (12) and an opening (121) connecting the cavity (12), the cavity (12) having a sealing plate (3) for abutting against and pressing against the end face of the pipe during pressure measurement, and the sealing plate (3) having an air supply hole (31). It also includes a fixed limiting plate (81), a pipe-holding sealing ring (4), and a moving block (2). The fixed limiting plate (81), the pipe-holding sealing ring (4), the sealing plate (3), and the moving block (2) are arranged in a direction from close to to far away from the opening (121). The pipe-holding sealing ring (4) is sandwiched between the fixed limiting plate (81) and the sealing plate (3). The fixed limiting plate (81) is provided with a pipe hole (811) corresponding to the position of the air supply hole (31). The sealing plate (3) and the moving block (2) can both move axially relative to the housing (1), and the moving block (2) is pressed against the sealing plate (3). The cavity (12) includes a power storage chamber (123) located on the side of the moving block (2) away from the sealing plate (3). The housing (1) is provided with a compression gas transmission channel (6) for connecting to an external gas transmission device. The compression gas transmission channel (6) is connected to the power storage chamber (123), so that when the pressure is measured, the moving block (2) squeezes the pipe-holding sealing ring (4) through the sealing plate (3), so that the inner diameter of the pipe-holding sealing ring (4) is reduced and it hugs the pipe located inside it, so that the inner side of the pipe-holding sealing ring (4) is sealed to the outer side wall of the pipe.

2. The pipe pressure testing head according to claim 1, characterized in that: The movable block (2) has a first protrusion (21) on the side away from the sealing plate (3). A recess (122) matching the first protrusion (21) is formed on the bottom surface of the cavity (12). The first protrusion (21) is at least partially located in the recess (122). A first sealing ring (23) is engaged between the outer wall of the first protrusion (21) and the inner wall of the recess (122). A second sealing ring (24) is engaged between the movable block (2) and the inner wall of the cavity (12). An annular step surface (26) is formed at the junction of the outer wall of the first protrusion (21) and the outer wall of the movable block (2). The first sealing ring (23), the inner wall of the pit (122), the bottom surface of the cavity (12), the inner wall of the cavity (12), the second sealing ring (24), the outer wall of the movable block (2), the annular step surface (26) and the outer wall of the first protrusion (21) enclose the power storage chamber (123). The outlet of the extrusion gas transmission channel (6) is located on the bottom surface of the cavity (12), and the inlet of the extrusion gas transmission channel (6) is located on the outer wall of the housing (1).

3. The pipe pressure testing head according to claim 2, characterized in that: The pipe pressure testing head is provided with a pressure testing gas supply channel (7). The pressure testing gas supply channel (7) includes a first pressure testing gas supply channel (71), a transition cavity (124), and a second pressure testing gas supply channel (72) connected in sequence. The first pressure testing gas supply channel (71) extends from the outer side wall of the housing (1) to the bottom surface of the pit (122). The second pressure testing gas supply channel (72) passes through the moving block (2) and the first protrusion (21) and connects to the gas supply through hole (31). The first sealing ring (23), the outer side wall of the first protrusion (21), the inner side wall of the pit (122), and the bottom surface of the pit (122) enclose the transition cavity (124).

4. The pipe pressure testing head according to claim 1 or 2, characterized in that: It also includes a pressure measuring sleeve (8), which is detachably connected to the housing (1) and at least partially disposed in the cavity (12). The fixed limiting plate (81), the tube sealing ring (4) and the sealing plate (3) are disposed in the pressure measuring sleeve (8). The outer side wall of the pressure measuring sleeve (8) and / or the inner side wall of the cavity (12) are provided with a limiting structure (9) to restrict the axial relative movement of the pressure measuring sleeve (8) and the housing (1).

5. The pipe pressure testing head according to claim 4, characterized in that: The movable block (2) has a second protrusion (22) on the side near the sealing plate (3). The second protrusion (22) extends into the inside of the pressure measuring sleeve (8) and squeezes the sealing plate (3). A third sealing ring (25) is engaged between the outer wall of the second protrusion (22) and the inner wall of the pressure measuring sleeve (8). The movable block (2) is located between the inner end face of the pressure measuring sleeve (8) and the bottom surface of the cavity (12) and can move axially between the inner end face of the pressure measuring sleeve (8) and the bottom surface of the cavity (12).

6. The pipe pressure testing head according to claim 4, characterized in that: The pressure testing sleeve (8) has one end protruding from the opening (121) away from the moving block (2) and is provided with a guide structure (5). The guide structure (5) is provided with a guide hole (51). The guide hole (51) is directly opposite the through hole (811). The diameter of the guide hole (51) gradually decreases in the direction from away from to close to the through hole (811). The guide hole (51) is used to guide the pipe into the through hole (811).

7. The pipe pressure testing head according to claim 4, characterized in that: The limiting structure (9) includes an external thread (82) on the outer side wall of the pressure measuring sleeve (8) and an internal thread (13) on the inner side wall of the cavity (12). The pressure measuring sleeve (8) is detachably connected to the housing (1) through the external thread (82) and the internal thread (13), and can be fixed relative to the housing (1) in the axial direction.

8. The pipe pressure testing head according to claim 7, characterized in that: The housing (1) is also provided with an exhaust hole (11) that connects to the cavity (12), and the exhaust hole (11) is directly opposite the internal thread (13).

9. A pipe pressure testing machine, characterized in that: Includes the pipe pressure testing head as described in any one of claims 1 to 8.

10. The pipe pressure testing machine according to claim 9, characterized in that: It includes a gas delivery device and at least two oppositely arranged pipe pressure test heads, the gas delivery device being connected to the extrusion gas delivery channel (6).

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