A pipe end self-tightening sealing pressure measuring device and pressure measuring method

Abstract

The present invention provides a pipe end self-pressing and sealing pressure measuring device and a pressure measuring method, comprising a header and a pressure measuring device body sleeved inside the open end of the header, the open end of the header is set as a stepped inner boring structure, which is convenient for installing the pressure measuring device body, the pressure measuring device body comprises a core shaft, a clamping device and an expansion sleeve, the core shaft is installed in the clamping device and the expansion sleeve, the core shaft is connected to the clamping device, the clamping device is connected to the expansion sleeve, the core shaft passes through the clamping device and abuts against one side of the expansion sleeve, the beneficial effect of the present invention is that it can be used for headers with open structures at both ends or headers with an open end and a closed structure at the other end, the pressure measuring device body is sleeved in the header, the size is adjusted according to the size of the header, and it has strong versatility and high practicality.

Description

Technical Field

[0001] The invention relates to the technical field of boiler assembly, and in particular to a pipe end self-compression sealing pressure measuring device and a pressure measuring method. Background Art

[0002] During the operation of the boiler, the steam is collected inside the header, so the sealing of the header needs to be tested by testing the water pressure. At present, for product headers with open structures at both ends or one end, before the water pressure test process, a water pressure test end cover must be installed or welded at the end of the open header body, and then the water pressure test process can be carried out. After the product header completes the water pressure test, it is also necessary to cut off the water pressure test end cover originally installed and welded at the header port position, and reprocess the header end margin and groove.

[0003] The use of this manufacturing method results in a long manufacturing cycle for the header, and for headers with open structures, water pressure test end covers of corresponding specifications are also required, which increases the manufacturing cost of the header and is not conducive to large-scale production in the workshop. Summary of the invention

[0004] In order to overcome the above problems existing in the prior art, the present invention provides a pipe end self-tightening and sealing pressure measuring device and a pressure measuring method.

[0005] The present invention discloses a pipe end self-compression sealing pressure measuring device and a pressure measuring method, comprising a header and a pressure measuring device body sleeved inside the open end of the header, the open end of the header is configured as a stepped inner boring structure to facilitate the installation of the pressure measuring device body, the pressure measuring device body comprises a core shaft, a clamping device and an expansion sleeve, the core shaft is installed in the clamping device and the expansion sleeve, the core shaft is connected to the clamping device, the clamping device is connected to the expansion sleeve, and the core shaft passes through the clamping device and abuts against one side of the expansion sleeve.

[0006] On this basis, the core shaft includes an inner cylinder, a cylinder and a rotating handle. The inner cylinder is set to a cylindrical shape, the same as the shape of the collecting box. The port of the inner cylinder away from the open end of the collecting box is narrowed inward into a cone, so that the inner cylinder can reach the expansion sleeve. The angle range of the cone angle a is 10~40°. The port at one end of the cylindrical inner cylinder is in a closed state. The cylinder is installed at the center position of the end face of the closed end of the inner cylinder. The rotating handle is fixed on the cylinder and is used to rotate to move the inner cylinder. At least two rows of hydrophobic holes are arranged on the inner cylinder, and the number of hydrophobic holes in each row is 20~100. The hydrophobic holes are used for the passage of water. First grooves are respectively opened on both sides of the hydrophobic holes. Sealing rings are installed in the first grooves to ensure that water will not flow out of the gap between the core shaft and the clamping device after flowing out of the hydrophobic holes.

[0007] On this basis, the clamping device includes an outer cylinder, a hand lever, a pressure cylinder, a piston ring and a hydrophobic waist circular hole. The pressure cylinder is sleeved in the middle position of the outer cylinder. The piston ring is installed on one side of the pressure cylinder and forms a sealed chamber with the pressure cylinder. The sealing of the collecting box is detected by detecting the water pressure after water enters the sealed chamber. The hand lever is arranged on the other side of the outer cylinder. Holding the hand lever can ensure that the clamping device will not move. The hydrophobic waist circular hole is arranged in the middle position of the outer cylinder and is located in the sealed chamber. Water enters the sealed chamber through the hydrophobic waist circular hole.

[0008] On this basis, a hydraulic jack is provided in the sealing cavity, and the two ends of the hydraulic jack are respectively connected to the pressure cylinder and the piston ring. A connecting line is provided at the tail of the hydraulic jack passing through the pressure cylinder, and the connecting line is connected to a manual controller. A pressure gauge is provided on the pressure cylinder. When the water pressure is insufficient, the hydraulic jack is controlled to reciprocate through the manual controller, and stops when the water pressure is sufficient. The water pressure is measured by a pressure gauge.

[0009] On this basis, a sealing ring is installed on the clamping device, and the sealing ring is fixed to the piston ring by screws. The sealing ring is set to be ring-shaped, which is the same as the side shape of the pressure cylinder, and the tightness of the sealing cavity is guaranteed after fitting.

[0010] On this basis, the expansion sleeve is tubular, and an intermittent step is provided in the middle of the expansion sleeve. The intermittent step is an evenly divided intermittent connection structure. The end of the intermittent step that contacts the core shaft can be deformed. The intermittent step is arranged in an annular shape in the expansion sleeve and is evenly distributed. A second groove is provided on the expansion sleeve, and a sealing ring is installed in the second groove to prevent water from flowing out of the gap between the collecting tank and the expansion sleeve.

[0011] On this basis, the step inner boring depth of the header is equal to the distance between the inner edge of the intermittent step and the inner hole of the expansion sleeve, the distance that the broken part of the intermittent step expands outward is equal to the inner boring depth of the header, the header step inner boring size is equal to the disconnection length of the intermittent step, the outer circle of the inner cylinder, the inner hole of the outer cylinder and the inner hole of the expansion sleeve are collinear, ensuring that the inner cylinder can pass through the clamping device to reach one side of the expansion sleeve, and the outer circle size of the expansion sleeve is the same as the inner diameter of the header, ensuring that the expansion sleeve can be installed in the header.

[0012] On this basis, the pressure measurement method using the pipe end self-tightening and sealing pressure measurement device comprises the following steps:

[0013] Step 1: The mandrel is rotated forward to move inward relative to the expansion sleeve and the clamping device, and the tapered port of the inner cylinder gradually presses against the discontinuous steps in the expansion sleeve, so that the expansion sleeve is in full contact with the inner boring area of ​​the header step;

[0014] Step 2: The header starts to drain water and perform a pressure operation. The water inside the header flows out from the drain hole in the inner cylinder of the core shaft, passes through the drain waist hole in the outer cylinder of the pressing device, and flows into the sealing cavity;

[0015] Step 3: When the water pressure is insufficient, the hydraulic jack is controlled to reciprocate synchronously through the manual controller. Through the reciprocating action of the hydraulic jack, the piston ring is synchronously reciprocated relative to the pressure cylinder, so that the sealing ring is pressed against the opening end face of the header. The water pressure inside the header is gradually increased, which can make the sealing ring automatically close to the product header port, realize the automatic sealing function of the header end, and complete the water pressure test;

[0016] Step 4: Reversely rotate the mandrel to move the mandrel outward relative to the expansion sleeve and the clamping device, and the tapered port of the inner cylinder gradually loosens the discontinuous steps in the expansion sleeve, so that the expansion sleeve is out of contact with the inner boring area of ​​the header step;

[0017] Step 5: The hydraulic jack can be controlled to realize reciprocating motion synchronously through the manual controller. Through the reciprocating motion of the hydraulic jack, the piston ring can finally realize the synchronous reciprocating motion relative to the pressure cylinder, so that the sealing ring is away from the end face of the manifold. The main body of the pressure measuring device is removed as a whole from the end of the product manifold, and the water left inside the manifold is emptied.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] (1) The pipe end self-tightening and sealing pressure measuring device and pressure measuring method of the present invention can be used for a header with open structures at both ends or a header with an open end and a closed structure at the other end. The main body of the pressure measuring device is mounted on the header port, and the size is adjusted according to the size of the header. It has strong versatility and high practicality.

[0020] (2) The pipe end self-tightening sealing pressure measuring device and pressure measuring method of the present invention, as the water pressure inside the product manifold increases, the sealing ring will move toward the manifold port until it is against the manifold end face, gradually realizing automatic tightening of the manifold end faces, and detecting the water pressure through a pressure gauge to finally complete the manifold water pressure test. When the water pressure is insufficient, the hydraulic jack is controlled by a manual controller to provide auxiliary function to ensure the operation of the device.

[0021] (3) The pipe end self-tightening and sealing pressure measuring device and pressure measuring method of the present invention, by reversely rotating the core shaft, the intermittent step returns to its original state after there is no force acting on it, and the expansion sleeve is in a non-fixed state with the inner wall of the header, so that the main body of the pressure measuring device can be removed as a whole, replacing the header water pressure test end cover currently in large-scale use in workshops, avoiding the need to cut off the water pressure test end cover originally welded to the header port position, and re-processing the header end margin and groove, thereby achieving the purpose of reducing the product header manufacturing cost and manufacturing cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the header structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the main structure of the pressure measuring device of the present invention;

[0024] Figure 3 It is a schematic diagram of the assembly structure of the pressure measuring device body and the header of the present invention;

[0025] Figure 4 It is a schematic diagram of the core shaft structure of the present invention;

[0026] Figure 5 It is a schematic diagram of the assembly structure of the cylinder and the inner cylinder of the present invention;

[0027] Figure 6 is a schematic diagram of the structure of a rotating handle in an embodiment of the present invention;

[0028] Figure 7 It is a schematic diagram of the structure of the clamping device of the present invention;

[0029] Figure 8 This is a schematic diagram of the sealing ring structure of the present invention

[0030] Fig. 9 It is a schematic diagram of the expansion sleeve structure of the present invention;

[0031] Fig.10 It is a schematic diagram of the discontinuous step structure of the present invention;

[0032] Fig.11 This is a schematic diagram of the structure of the embodiment of the present invention when the mandrel rotates forward;

[0033] Fig.12 It is a schematic diagram of the structure when the mandrel is reversed in an embodiment of the present invention.

[0034] In the figure: 1, collecting box, 2, core shaft, 2-1, inner cylinder, 2-2, cylinder, 2-3, rotating handle, 2-4, drain hole, 2-5, first groove, 3, clamping device, 3-1, outer cylinder, 3-2 hand lever, 3-3, pressure cylinder, 3-4 piston ring, 3-5 hydraulic jack, 3-6, pressure gauge, 3-7, manual controller, 3-8, drain waist hole, 3-9, connecting line, 3-10, sealing chamber, 3-11, sealing ring, 4, expansion sleeve, 4-1, second groove, 4-2, intermittent step. DETAILED DESCRIPTION

[0035] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0036] The present invention discloses a pipe end self-tightening sealing pressure measuring device and a pressure measuring method, referring to Figure 3 , the water pressure of the header 1 is tested by using a pressure measuring device body mounted inside the opening end of the header 1, referring to Figure 1 The opening end of the header 1 is set as a stepped internal boring structure. The header 1 is cylindrical. The main body of the tube end self-pressure sealing device is sleeved inside the right side of the header 1. The inner diameter of the header 1 is set to Φ1, the outer diameter is set to Φ2, and Φ1<Φ2. The opening end of the header 1 is set to a stepped internal boring structure, the step internal boring depth is S1, the dimension from the end face of the header 1 to the step internal boring is L1, and the step internal boring dimension is L2.

[0037] refer to Figure 2 As a preferred embodiment of the present invention, in this embodiment, the main body of the pressure measuring device includes a core shaft 2, a clamping device 3 and an expansion sleeve 4. The core shaft 2 is installed in the clamping device 3 and the expansion sleeve 4. The core shaft 2 passes through the inside of the clamping device 3 from right to left and contacts the right end of the expansion sleeve 4. The core shaft 2 and the clamping device 3 are threadedly connected, and the clamping device 3 and the expansion sleeve 4 are threadedly connected.

[0038] refer to Figure 4 and Figure 5 As a preferred embodiment of the present invention, in this embodiment, the core shaft 2 includes an inner cylinder 2-1, a cylinder 2-2 and a rotating handle 2-3. The inner cylinder 2-1 is set to a cylindrical shape, the cylinder 2-2 is installed at the center position of the right end face of the inner cylinder 2-1, and the rotating handle 2-3 is fixed on the cylinder 2-2. The outer circle of the inner cylinder 2-1 is set to Φ3, the right end port of the inner cylinder 2-1 is in a closed state, the left end port of the inner cylinder 2-1 is in a conical shape, and the right end of the inner cylinder 2-1 is provided with an external thread on the outer side.

[0039] refer to Figure 7 As a preferred embodiment of the present invention, in this embodiment, the pressing device 3 includes an outer cylinder 3-1, a hand lever 3-2, a pressure cylinder 3-3, a piston ring 3-4 and a hydrophobic waist hole 3-8. The outer cylinder 3-1 is cylindrical, and the inner hole of the outer cylinder 3-1 is set to Φ3′. Both ends of the outer cylinder 3-1 are provided with internal threads. Figure 2 The internal thread on the right side of the outer cylinder 3-1 is meshed with the external thread of the inner cylinder 2-1, so that the positions of the outer cylinder 3-1 and the inner cylinder 2-1 are relatively fixed, that is, the positions of the core shaft 2 and the clamping device 3 are fixed.

[0040] refer to Fig. 9 and Fig.10, a preferred embodiment of the present invention, in this embodiment, the expansion sleeve 4 is tubular, the outer circle of the expansion sleeve 4 is set to Φ1′, the inner hole of the expansion sleeve 4 is set to Φ3″, and an intermittent step 4-2 is provided at the middle position of the expansion sleeve 4. The intermittent step 4-2 is an evenly divided intermittent connection structure, and the end of the intermittent step 4-2 in contact with the core shaft 2 can be deformed. The intermittent step 4-2 is set to be annular, and an external thread is provided on the right side of the expansion sleeve 4. The external thread of the expansion sleeve 4 is engaged with the internal thread on the left side of the clamping device 3, so that the clamping device 3 and the expansion sleeve 4 are fixed.

[0041] refer to Figure 3 The core shaft 2, the clamping device 3 and the expansion sleeve 4 are fixed to each other through the cooperation between the threads to form the main body of the pressure measuring device.

[0042] During assembly, first put the expansion sleeve 4 into the collection box 1, the outer circle size Φ1′ of the expansion sleeve 4 is the same as the inner diameter size Φ1 of the collection box 1, to ensure that the expansion sleeve 4 can be installed in the collection box 1, then the clamping device 3 and the expansion sleeve 4 are fixed by threaded connection, and finally the core shaft 2 and the clamping device 3 are fixed by threaded connection, the inner hole size Φ3′ of the outer cylinder 3-1 is equal to the outer circle size Φ3 of the inner cylinder 2-1, to ensure that the inner cylinder 2-1 can pass through the clamping device 3, the outer circle size Φ3 of the inner cylinder 2-1, the inner hole size Φ3′ of the outer cylinder 3-1 and the inner hole size Φ3″ of the expansion sleeve 4 are the same, to ensure that the expansion sleeve 4 and the clamping device 3 are fixed, and the inner cylinder 2-1 can pass through the clamping device 3 and contact the expansion sleeve 4.

[0043] When conducting a water pressure test, refer to Figure 4 and Fig.11 , rotating the handle 2-3 in the positive direction drives the cylinder 2-2 to rotate, thereby driving the core shaft 2 to rotate, refer to Figure 6 As a preferred embodiment of the present invention, in this embodiment, the rotating handle 2-3 is composed of a ring 2-3-1 and at least one connecting rod 2-3-2, the connecting rod 2-3-2 is welded between the cylinder 2-2 and the ring 2-3-1, and the connecting rod 2-3-2 is 4 in number and is installed in a cross state between the inner cylinder 2-1 and the ring 2-3. Figure 7 and Fig.11The hand lever 3-2 is arranged on the right side of the outer cylinder 3-1. The hand lever 3-2 is held on the right side of the outer cylinder 3-1. The function of the hand lever 3-2 is to ensure that the clamping device 3 does not move arbitrarily when the core shaft 2 is rotated, so that the clamping device 3 and the expansion sleeve 4 are fixed in position. The core shaft 2 moves inward relative to the clamping device 3 and the expansion sleeve 4. The tapered port of the inner cylinder 2-1 gradually presses against the discontinuous step 4-2 in the expansion sleeve 4, so that the end of the discontinuous step 4-2 in contact with the core shaft 2 is deformed and is set to a cone to facilitate contact with the expansion sleeve 4. The angle range of the cone angle is 10 to 40°. When the angle of the cone angle is larger, the range of deformation of the discontinuous step 4-2 is larger, which is unsafe for the entire device. As a preferred embodiment of the present invention, in this embodiment, the angle of the cone angle is 25°, and the disconnection length of the discontinuous step 4-2 is set to L2′. The disconnection length of the intermittent step 4-2 is equal to the step inner boring size L2 in the collection box 1, ensuring that the intermittent step 4-2 can be pressed against the inner wall of the step inner boring in the collection box 1 after being extruded and deformed. The number of intermittent steps 4-2 is 8-16. The fewer the number of intermittent steps 4-2, the greater the rigidity, and the smaller the deformation under the extrusion of the core shaft 2, but the effect is poor at this time. The distance between the inner edge of the intermittent step 4-2 and the inner hole of the expansion sleeve 4 is set to S1′, and the distance S1′ between the inner edge of the intermittent step 4-2 and the inner hole of the expansion sleeve 4 is equal to the step inner boring depth S1 of the collection box 1, ensuring that when the left end of the core shaft 4 presses against the broken part of the intermittent step 4-2, the distance that the broken part expands outward is also equal to the inner boring depth of the collection box 1, so that the expansion sleeve 4 is completely in contact with the step inner boring area of ​​the collection box 1, ensuring that the expansion sleeve 4 and the collection box 1 can be firmly installed and water will not leak.

[0044] The header 1 starts to release water and perform pressure reduction operation. Fig. 9 The expansion sleeve 4 is provided with a groove 4-1, which is opened on the left side of the intermittent step 4-2. A sealing ring is installed in the groove 4-1 to prevent the water in the header 1 from leaking from the gap between the inner wall of the header 1 and the expansion sleeve 4. Figure 4 Three rows of drain holes 2-4 are arranged on the inner cylinder 2-1, and the number of drain holes 2-4 in each row is 60. First grooves 2-5 are respectively opened on both sides of the drain holes 2-4. Sealing rings are installed in the first grooves 2-5 to ensure that water will not flow out of the gap between the core shaft 2 and the clamping device 3 after flowing out of the drain holes 2-4. The water inside the collecting box 1 enters the inner cylinder 2-1 and flows out from the drain holes 2-4 in the inner cylinder 2-1.

[0045] refer to Figure 7As a preferred embodiment of the present invention, in this embodiment, the pressure cylinder 3-3 is sleeved in the middle of the outer cylinder 3-1, the pressure cylinder 3-3 is a cavity structure, the piston ring 3-4 is installed on the left side of the pressure cylinder 3-3 and forms a sealed cavity 3-10 with the pressure cylinder 3-3, the hydrophobic waist hole 3-8 is arranged in the middle of the outer cylinder 3-1 and is located in the sealed cavity 3-10, water flows out of the hydrophobic waist hole 3-8 into the sealed cavity 3-10, the left side of the clamping device 3 is movable, and a sealing ring 3-11 is installed on the clamping device 3, and the sealing ring 3-11 is fixed to the piston ring 3-4 by screws, refer to Figure 8 , the sealing ring 3-11 is set to be annular.

[0046] refer to Figure 7 As a preferred embodiment of the present invention, in this embodiment, when the water pressure is insufficient, the sealed cavity 3-10 is provided with a hydraulic jack 3-5, and the two ends of the hydraulic jack 3-5 are respectively connected to the pressure cylinder 3-3 and the piston ring 3-4. The hydraulic jack 3-5 is provided with two pieces, which are respectively arranged at the upper end and the lower end of the pressure cylinder 3-3. The positions of the two hydraulic jacks 3-5 are set to a symmetrical state to balance the force. The tail of the hydraulic jack 3-5 passes through the pressure cylinder 3-3 and is provided with a connecting line 3-9. The connecting line 3-9 is connected to the manual controller 3-7. The manual controller 3-7 controls the hydraulic jack 3-5, so that the hydraulic jack The top 3-5 realizes reciprocating motion synchronously, and the reciprocating motion of the hydraulic jack 3-5 realizes the synchronous reciprocating motion of the piston ring 3-4 relative to the pressure cylinder 3-3. The sealing ring 3-11 moves to the left to press against the open end face of the collection box 1. The water pressure inside the collection box 1 gradually increases, which can make the sealing ring 3-11 automatically close to the port of the product collection box 1, and realize the automatic sealing function of the end of the collection box 1. At the same time, it also ensures that even if water seeps out from the thread between the clamping device 3 and the expansion sleeve 4, it circulates inside the collection box 1 and will not leak to the outside of the collection box 1. A pressure gauge 3-6 is provided at the bottom of the pressure cylinder 3-3. The water pressure test is completed by detecting the water pressure in the sealing chamber 3-10 through the pressure gauge 3-6.

[0047] refer to Fig.12, rotate the core shaft 2 in the opposite direction to realize the movement of the core shaft 2 outward relative to the expansion sleeve 4 and the clamping device 3, and the tapered port of the inner cylinder 2-1 gradually loosens the discontinuous step 4-2 in the expansion sleeve 4, so that the expansion sleeve 4 is out of contact with the stepped inner boring area of ​​the manifold 1; the hydraulic jack 3-5 can be synchronously controlled to realize reciprocating motion through the manual controller 3-7, and the reciprocating motion of the hydraulic jack 3-5 is finally realized to realize the synchronous reciprocating motion of the piston ring 3-4 relative to the pressure cylinder 3-3, so that the sealing ring 3-11 is away from the end face of the manifold 1, at this time, the pressure in the manifold 1 changes, and the discontinuous step 2-11 of the expansion sleeve 4 returns to its original state, and the main body of the pressure measuring device can be removed from the end of the manifold 1 as a whole, and the water remaining in the manifold 1 is emptied.

[0048] The dimensions of the various components in the pressure measuring device body are set according to the dimensions of the header 1, which has universal applicability.

[0049] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0050] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation", "screwing", "pad installation" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0051] The above description shows and describes the preferred embodiments of the present invention. As mentioned above, it should be understood that the present invention is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified within the scope of the invention concept described herein through the above teachings or the technology or knowledge of the relevant field. The changes and modifications made by those skilled in the art do not depart from the spirit and scope of the present invention, and should be within the scope of protection of the claims attached to the present invention.

Claims

1. A pipe end self-tightening and sealing pressure measuring device, characterized in that: The invention comprises a manifold (1) and a pressure measuring device body sleeved inside the open end of the manifold (1); the open end of the manifold (1) is configured as a stepped inner boring structure; the pressure measuring device body comprises a core shaft (2), a clamping device (3) and an expansion sleeve (4); the core shaft (2) is installed in the clamping device (3) and the expansion sleeve (4); the core shaft (2) is connected to the clamping device (3); and the clamping device (3) is connected to the expansion sleeve (4); the core shaft (2) comprises an inner cylinder (2-1), a cylinder (2-2) and a rotating handle (2-3); the inner cylinder (2-1) is configured as a cylindrical shape; the port of the inner cylinder (2-1) away from the open end of the manifold (1) is reduced inwardly to a cone shape, and the angle range of the cone angle a is 10 to 40 degrees. The cylindrical end of the inner cylinder (2-1) is in a closed state. The cylinder (2-2) is mounted at the center of the closed end surface of the inner cylinder (2-1). The rotating handle (2-3) is fixed on the cylinder (2-2). At least two rows of hydrophobic holes (2-4) are arranged on the inner cylinder (2-1). The number of the hydrophobic holes (2-4) in each row is 20 to 100. First grooves (2-5) are respectively provided on both sides of the hydrophobic holes (2-4). A sealing ring is installed in the first groove (2-5). The pressing device (3) comprises an outer cylinder (3-1), a hand lever (3-2), a pressure cylinder (3-3), a piston ring (3-4) and a hydrophobic waist hole (3-8). The pressure cylinder (3-3) is sleeved on the outer cylinder. (3-1), the piston ring (3-4) is installed on one side of the pressure cylinder (3-3) and forms a sealed chamber (3-10) with the pressure cylinder (3-3), the hand lever (3-2) is arranged on the other side of the outer cylinder (3-1), the hydrophobic waist hole (3-8) is arranged in the middle of the outer cylinder (3-1) and is located in the sealed chamber (3-10); a hydraulic jack (3-5) is arranged in the sealed chamber (3-10), the two ends of the hydraulic jack (3-5) are respectively connected to the pressure cylinder (3-3) and the piston ring (3-4), and a connecting line (3-9) is arranged at the tail of the hydraulic jack (3-5) passing through the pressure cylinder (3-3), and the connecting line (3-9) is connected to the manual controller ( 3-7), a pressure gauge (3-6) is provided on the pressure cylinder (3-3); a sealing ring (3-11) is installed on the pressing device (3), the sealing ring (3-11) and the piston ring (3-4) are fixed by screws, and the sealing ring (3-11) is set to be annular; the expansion sleeve (4) is tubular, and an intermittent step (4-2) is provided at the middle position of the expansion sleeve (4), and the intermittent step (4-2) is an evenly divided intermittent connection structure, and the end of the intermittent step (4-2) that contacts the core shaft (2) can be deformed, and the intermittent step (4-2) is arranged in an annular shape in the expansion sleeve (4), and a second groove (4-1) is provided on the expansion sleeve (4), and a sealing ring is installed in the second groove (4-1).

2. The pipe end self-tightening and sealing pressure measuring device according to claim 1, characterized in that: The step inner boring depth of the header (1) is equal to the distance between the inner edge of the intermittent step (4-2) and the inner hole of the expansion sleeve (4); the distance that the broken part of the intermittent step (4-2) expands outward is equal to the inner boring depth of the header (1); the step inner boring size of the header (1) is equal to the disconnection length of the intermittent step (4-2); the outer circle of the inner cylinder (2-1), the inner hole of the outer cylinder (3-1) and the inner hole of the expansion sleeve (4) are collinear; and the outer circle size of the expansion sleeve (4) is the same as the inner diameter of the header (1).

3. A pressure measuring method using the pipe end self-tightening and sealing pressure measuring device according to claim 1, characterized in that: The following steps are involved: Step 1: The core shaft (2) is rotated forward to move the core shaft (2) inward relative to the expansion sleeve (4) and the clamping device (3), and the conical port of the inner cylinder (2-1) gradually presses against the discontinuous step (4-2) in the expansion sleeve (4), so that the expansion sleeve (4) is in full contact with the stepped inner boring area of ​​the header (1); Step 2: The header (1) begins to drain water and perform a pressure operation, and the water inside the header (1) flows out from the drain hole (2-4) in the inner cylinder (2-1) in the core shaft (2), passes through the drain waist hole (3-8) in the outer cylinder (3-1) in the pressing device (3), and flows into the sealing cavity (3-10); Step 3: When the water pressure is insufficient, the manual controller (3-7) is used to synchronously control the hydraulic jack (3-5) to realize reciprocating motion. The reciprocating motion of the hydraulic jack (3-5) is used to synchronously realize reciprocating motion of the piston ring (3-4) relative to the pressure cylinder (3-3), so that the sealing ring (3-11) is pressed against the open end surface of the header (1). The water pressure inside the header (1) is gradually increased, so that the sealing ring (3-11) can automatically fit closely to the port of the product header (1), realizing the automatic sealing function of the end of the header (1), and completing the water pressure test; Step 4: The core shaft (2) is rotated in the opposite direction to move the core shaft (2) outward relative to the expansion sleeve (4) and the clamping device (3), and the tapered port of the inner cylinder (2-1) gradually loosens the discontinuous step (4-2) in the expansion sleeve (4), so that the expansion sleeve (4) is out of contact with the stepped inner boring area of ​​the header (1); Step 5: The manual controller (3-7) can be used to synchronously control the reciprocating motion of the hydraulic jack (3-5). Through the reciprocating motion of the hydraulic jack (3-5), the piston ring (3-4) can eventually synchronously reciprocate relative to the pressure cylinder (3-3), so that the sealing ring (3-11) is away from the end face of the manifold (1), and the main body of the pressure measuring device is completely removed from the end of the product manifold (1), and the water remaining in the manifold (1) is emptied.

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