Universal steel pipe pressure test device and operation method thereof

Abstract

The present invention relates to the technical field of steel pipe water pressure testing machinery, and in particular to a universal steel pipe pressure testing device and an operating method thereof, wherein the structure comprises a pressure testing machine, a feed side track, a discharge side track and a water pressure system, wherein the pressure testing machine is arranged at a pressure testing position between the feed side track and the discharge side track, and the water pressure system is connected to the pressure testing machine; the pressure testing machine comprises a gantry, a pipe head sealing seat and a pipe tail sealing seat, wherein the pipe head sealing seat and the pipe tail sealing seat are respectively connected to the two side columns of the gantry via a hydraulic cylinder and a vertical slide seat, and the pipe head sealing seat and the pipe tail sealing seat are respectively provided with a plurality of groups of concentrically arranged sealing rings, and the size of a certain group of sealing rings matches the nominal diameter of a certain specification of steel pipe. Compared with the prior art, the beneficial effects of the present invention are: 1) it can meet the batch water pressure test of a certain length of fixed-length spiral welded pipes, and is universal for several specifications of steel pipes; 2) it meets conventional pressure testing requirements and can realize continuous operation.

Description

Technical Field

[0001] The invention relates to the technical field of steel pipe water pressure testing machinery, and in particular to a universal steel pipe pressure testing device and an operating method thereof. Background Art

[0002] Pipelines are widely used in various fields such as petroleum, chemical industry, shipbuilding, machinery manufacturing, energy, geology, etc. In applications such as oil casing and transmission pipes, the quality requirements are relatively strict. During the production process, steel pipes will have defects such as pits, folds, cracks or debonding. These defects will cause unnecessary losses during use. Therefore, many applications require steel pipes to be tested for water pressure before leaving the factory.

[0003] The process of water pressure testing is: 1) Observe for 10 minutes under the test pressure, the pressure drop should not be greater than 0.02MPa, then reduce to the working pressure for inspection, there should be no leakage. 2) When the pipeline is pressurized, the gas in the pipeline should be exhausted. During the pressure increase process, if the needle of the spring pressure gauge is found to be swinging, unstable, and the pressure increase is slow, the gas should be re-exhausted before the pressure is increased; 3) The pressure should be increased in stages, and the back, piers, pipe body and interface should be checked for each level. When there is no abnormality, continue to increase the pressure; 4) During the water pressure test, the back is supported, and it is strictly forbidden to stand at both ends of the pipeline; 5) During the water pressure test, it is strictly forbidden to knock on the pipe body and interface or repair defects. If there are defects, they should be marked and repaired after the pressure is released.

[0004] The Chinese invention patent with patent application number 201410392609.8 discloses a steel pipe water pressure detection device, including a frame; a steel pipe left clamping mechanism and a steel pipe water injection mechanism, which are arranged at the left end of the frame; a steel pipe right clamping mechanism and a steel pipe port closing mechanism, which are arranged at the right end of the frame; a steel pipe left lifting mechanism and a steel pipe right lifting mechanism, the steel pipe left lifting mechanism is supported on the floor at a position corresponding to the right side of the steel pipe left clamping mechanism, and the steel pipe right lifting mechanism is supported on the floor at a position corresponding to the right side of the steel pipe right clamping mechanism; a steel pipe traction mechanism, which is supported on the floor at a position corresponding to the middle of the frame. The device has high detection efficiency and can meet the comprehensive detection of the steel pipes produced by the steel pipe manufacturer, avoiding the backlog of steel pipes to be inspected; reducing the work intensity of online inspection personnel and ensuring safety; it is beneficial for the steel pipe manufacturer to control the quality of the steel pipes it produces, and preventing the phenomenon of unqualified defective steel pipes mixed with qualified steel pipes. Summary of the invention

[0005] The purpose of the present invention is to provide a universal steel pipe pressure test device and an operating method thereof, which overcomes the shortcomings of the prior art, meets the needs of batch water pressure testing of spiral welded pipes of fixed lengths, is universal for steel pipes of several diameters, and has two sealing heads that can be movably aligned and engaged with the ends of the steel pipes to form a closed cavity inside the steel pipes. Water is injected and the exhaust is automatically exhausted at the same time. After the gas is exhausted, the exhaust valve is closed and the pressure test procedure is executed. When the water pressure test pressure reaches 1.4 times the design pressure, the pressure is maintained for 30 minutes. If there is no leakage, the water in the steel pipe is released and the test is completed. If there is a leakage, mark the corresponding position. After all leakage points are marked, the water is released, the steel pipe is removed, and the next steel pipe is tested.

[0006] To achieve the above object, the present invention is implemented through the following technical solutions:

[0007] Technical Solution 1: A universal steel pipe pressure test device, which includes a pressure machine, a feed side track, a discharge side track and a water pressure system. The pressure machine is set at the pressure position between the feed side track and the discharge side track, and the water pressure system is connected to the pressure machine; the pressure machine includes a gantry, a pipe head sealing seat and a pipe tail sealing seat, the pipe head sealing seat and the pipe tail sealing seat are respectively connected to the two side columns of the gantry through a hydraulic cylinder and a vertical slide seat, and the pipe head sealing seat and the pipe tail sealing seat are respectively provided with a plurality of groups of concentrically arranged Sealing rings, a drain pipe is provided on the lower side of each group of sealing rings of the pipe head sealing seat, and the outside of the drain pipe is connected to a drain valve; an exhaust pipe is provided on the upper side of each group of sealing rings of the pipe tail sealing seat, the inner side of the exhaust pipe is bent upward and opened at the high point of the inner wall of the steel pipe to be pressed, and the outer side of the exhaust pipe is connected to the exhaust valve; the size of a certain group of sealing rings matches the nominal diameter of a certain specification of steel pipe; the water pressure system includes a water pump, a water tank, a valve and a pipeline, and the output end of the water pump is connected to the pipe tail sealing seat through a pipeline and the outlet is at the center of the pipe tail sealing seat.

[0008] The sealing ring includes a conical rubber seat ring and a lip sealing ring. Three to four metal flip bodies are evenly arranged in the circumferential direction inside the conical rubber seat ring. The cross-section of the metal flip body is L-shaped, including a bottom side, a long side and an inflection point. The bottom side is located in the conical rubber seat ring, and the long side is located in the lip sealing ring. The bottom side is connected to a compression spring, and the inflection point is hinged to the metal back plate by a pin.

[0009] Two V-shaped hydraulic brackets are arranged on the pressing position, one of which is located on the pipe head sealing seat side and the other is located on the pipe tail sealing seat side. The V-shaped hydraulic bracket on the pipe tail sealing seat side is 10-20mm higher than the V-shaped hydraulic bracket on the pipe head sealing seat side.

[0010] A waiting area is provided on the feed side track, and 1 to 2 waiting flaps are provided between the tracks of the waiting area. One end of the waiting flap is connected to the hinge shaft, and the other end is connected to the piston end of the waiting action cylinder.

[0011] A buffer area is provided at the end of the discharge side track, and 1 to 2 buffer flaps are provided between the tracks of the buffer area. One end of the buffer flap is connected to the hinge shaft, and the other end is connected to the piston end of the buffer action cylinder.

[0012] The vertical slide is provided with a nut, which is matched with a ball screw. Both ends of the ball screw are connected to the columns of the gantry through bearing seats. The end of the ball screw is connected to a slide motor. The vertical slide and the column are also matched and connected through a dovetail groove guide rail.

[0013] The pressing position is provided with a steel tapping flap, one end of which is connected to the hinge shaft, and the other end is connected to the piston end of the steel tapping action cylinder.

[0014] Technical Solution 2: Operation method of the universal steel pipe pressure test device, the specific operation steps are as follows:

[0015] 1) The steel pipe to be pressed is lifted by a crane to the waiting area, and the waiting flap moves, so that the steel pipe to be pressed in the waiting area rolls along the feed side track to the pressing position;

[0016] 2) The V-shaped hydraulic bracket on the pressure-pressing position rises to lift the steel pipe to be pressed. The two ends of the steel pipe to be pressed are respectively in place with the sealing rings on the pipe head sealing seat and the pipe tail sealing seat. The hydraulic cylinder extends so that the pipe head sealing seat and the pipe tail sealing seat firmly clamp the steel pipe to be pressed;

[0017] 3) Before injecting water into the water pressure system network, close the drain valve, open the exhaust valve, and slowly increase the pressure during the water injection process. The pressure increase rate should be controlled at no more than 0.1MPa / minute. During the water injection, observe whether the welds on the steel pipes to be pressurized are leaking;

[0018] When the design working pressure of the steel pipe to be pressurized is equal to or less than 1.0MPa, the water pressure strength test pressure should be 1.5 times the design working pressure and should not be lower than 1.4MPa; when the system design working pressure is greater than 1.0MPa, the water pressure strength test pressure should be the working pressure plus 0.4MPa;

[0019] 4) When the water pressure system reaches the test pressure, the pressure should be stabilized for 30 to 45 minutes. The pipe network should have no leakage or deformation, and the pressure drop should not be greater than 0.05 MPa. It is considered that the steel pipe to be pressurized has no leakage;

[0020] 5) Open the drain valve on the pipe head sealing seat to drain all the water in the steel pipe to be pressurized;

[0021] 6) The hydraulic cylinder retracts, and the pipe head sealing seat and the pipe tail sealing seat retreat respectively to release the steel pipe to be pressed. The steel discharge flap moves to push the pressed steel pipe to the discharge side track. The steel pipe rolls along the discharge side track to the buffer area, and the buffer flap moves to keep the steel pipe in the buffer area until it is lifted away by the crane.

[0022] When the ambient temperature is lower than 5°C during the water pressure test, a heating device is used in the water pressure system as an anti-freezing measure.

[0023] Before the water pressure system is subjected to water injection pressure test, a water pressure tightness test shall be carried out after the water pressure strength test and pipe network flushing are qualified. The test pressure shall be the design working pressure, and there shall be no leakage after the pressure is stabilized for 24 hours.

[0024] Compared with the prior art, the beneficial effects of the present invention are: 1) it can meet the batch water pressure test of a certain length of spiral welded pipes, which is common to several steel pipes of similar specifications. The sealing seats on both sides are movable, which is convenient for centering and positioning. The sealing seats are engaged with the ends of the steel pipe to form a closed cavity inside the steel pipe, and the pressure testing procedure is automatic; 2) it is suitable for the pressure testing process of spiral welded pipes, meets conventional pressure testing requirements, and can realize continuous operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention.

[0026] Figure 2 yes Figure 1 A-direction view.

[0027] Figure 3 yes Figure 2 Partial cross-sectional view along line BB.

[0028] Figure 4 It is a cross-sectional schematic diagram of the sealing ring of the pipe head sealing seat of the present invention.

[0029] Figure 5 It is a cross-sectional schematic diagram of the sealing ring of the pipe tail sealing seat of the present invention.

[0030] Figure 6 This is a schematic diagram of the sealing ring in non-working state.

[0031] Figure 7 It is a schematic diagram of the flap structure of the present invention.

[0032] Figure 8 It is a schematic diagram of the structure of the V-shaped hydraulic bracket of the present invention.

[0033] In the figure: 1-pressing machine, 2-feeding side track, 3-discharging side track, 4-hydraulic system, 5-hydraulic cylinder, 6-vertical slide, 7-column, 8-sealing ring, 9-drain pipe, 10-drain valve, 11-gantry, 12-pipe head sealing seat, 13-pipe tail sealing seat, 14-V-shaped hydraulic bracket, 15-waiting flap, 16-buffer flap, 17-steel discharge flap, 18-metal back plate, 19-pin , 20-exhaust pipe, 21-steel pipe to be pressed, 22-exhaust valve, 23-hinge shaft, 24-flap, 25-acting cylinder, 26-nut, 27-ball screw, 28-bearing seat, 29-slide motor, 30-dovetail groove guide rail, 31-stop flap, 32-V-shaped bracket, 33-hydraulic cylinder body, 81-conical rubber seat ring, 82-lip sealing ring, 83-metal flip body, 84-compression spring. DETAILED DESCRIPTION

[0034] The embodiments of the present invention are further described below in conjunction with the embodiments:

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] See Figure 1-Figure 6, is a schematic structural diagram of an embodiment of a universal steel pipe pressure test device of the present invention, comprising a pressure machine 1, a feed side track 2, a discharge side track 3 and a hydraulic system 4, the pressure machine 1 is arranged at the pressure position between the feed side track 2 and the discharge side track 3, and the hydraulic system 4 is connected to the pressure machine 1; the pressure machine 1 comprises a gantry 11, a pipe head sealing seat 12 and a pipe tail sealing seat 13, the pipe head sealing seat 12 and the pipe tail sealing seat 13 are respectively connected to the columns 7 on both sides of the gantry through a hydraulic cylinder 5 and a vertical slide 6, a nut 26 is provided on the vertical slide 6, the nut is matched with a ball screw 27, both ends of the ball screw are connected to the column 7 through a bearing seat 28, the end of the ball screw is connected to a slide motor 29, and the vertical slide 6 and the column 7 are also matched and connected through a dovetail groove guide rail 30. The pipe head sealing seat 12 and the pipe tail sealing seat 13 are respectively provided with multiple sets of concentrically arranged sealing rings 8. Each set of sealing rings on the pipe head sealing seat 12 is provided with a drain pipe 9 on the lower side, and the drain pipe is connected to a drain valve 10. Each set of sealing rings on the pipe tail sealing seat 13 is provided with an exhaust pipe 20 on the upper side. The inner side of the exhaust pipe is bent upward and opened at the inner wall high point of the steel pipe 21 to be pressed. The outer side of the exhaust pipe 20 is connected to the exhaust valve 22. The size of a set of sealing rings matches the nominal diameter of a steel pipe of a certain specification. The hydraulic system 4 includes a water pump 41, a water tank 42, a valve 43 and a pipeline 44. The output end of the water pump 41 is connected to the pipe tail sealing seat 13 through a pipeline 44 and the outlet is at the center of the pipe tail sealing seat. The feed side track 2 and the discharge side track 3 can be set with an inclination angle of 10 mm / m according to the situation, so that the steel pipe can roll freely without being too fast to be controlled.

[0037] The sealing ring 8 includes a conical rubber seat ring 81 and a lip sealing ring 82. Three to four metal flip bodies 83 are evenly arranged in the conical rubber seat ring 81 along the circumferential direction. The cross section of the metal flip body is L-shaped, including a bottom side a, a long side b and an inflection point c. The bottom side a is located in the conical rubber seat ring 81, and the long side b is located in the lip sealing ring 82. The bottom side a is connected to the compression spring 84, and the inflection point c is hinged to the metal back plate 18 by a pin 19. When the device is in a non-working state, the lip sealing ring 82 is retracted inward due to the position of the metal flip body 83, which facilitates the placement of the steel pipe to be pressed and can avoid the steel pipe being scratched by the lip sealing ring when it is in place, causing damage to the sealing ring.

[0038] The feeding side of the feed side track 2 is provided with a waiting area, and two waiting flaps 15 are provided between the tracks in the waiting area, one end of the waiting flap is connected to the hinge shaft, and the other end is connected to the piston end of the waiting action cylinder. The function of the waiting flap 15 is to block the steel pipes to be pressed in the waiting area and release them one by one when needed. The head end of the discharge side track 3 is also provided with a stop flap 31, which is used to limit the rolling steel pipes to be pressed so that they stay in the pressing position.

[0039] A buffer area is provided at the tail end of the discharge side track 3, and two buffer flaps 16 are provided between the tracks of the buffer area, one end of the buffer flap is connected to the hinge shaft, and the other end is connected to the piston end of the buffer action cylinder. The function of the buffer flap 16 is to limit the steel pipe from rolling further when the pressed steel pipe enters the buffer area, waiting for the crane to lift it.

[0040] The feeding side of the pressing position is also provided with a steel tapping flap 17, one end of which is connected to the hinge shaft, and the other end is connected to the piston end of the steel tapping action cylinder. The function of the steel tapping flap 17 is to push the steel pipe to roll to the buffer area after the steel pipe is pressed at the pressing position.

[0041] In the embodiment, see Figure 7 The structures of the material waiting flap 15, the buffer flap 16, the steel-discharging flap 17 and the stop flap 31 are the same, and all include a hinge shaft 23, a flap 24, and an actuating cylinder 25. The flap 24 is hinged to a ground fixture by a hinge shaft, and the piston end of the actuating cylinder 25 is connected to the back of the end plate. When the actuating cylinder 25 is actuated, the flap 24 can be erected or laid flat to achieve restriction or release of the steel pipe.

[0042] See Figure 8 Two V-shaped hydraulic brackets 14 are provided on the pressing position, one of which is located on the side of the pipe head sealing seat 12 and the other is located on the side of the pipe tail sealing seat 13. The V-shaped hydraulic bracket on the side of the pipe tail sealing seat is 10-20 mm higher than the V-shaped hydraulic bracket on the side of the pipe head sealing seat. Its structure consists of an upper V-shaped bracket 32 ​​and a hydraulic cylinder body 33 at the bottom. The lifting and lowering of the V-shaped bracket 32 ​​is controlled and regulated by the hydraulic cylinder body 33.

[0043] The operating method of the universal steel pipe pressure test device of the present invention has the following specific operating steps:

[0044] 1) The steel pipe 21 to be pressed is lifted by a crane to the waiting area, and the waiting flap 15 moves, so that the steel pipe to be pressed in the waiting area rolls along the feed side track to the pressing position;

[0045] 2) The V-shaped hydraulic bracket 14 on the pressing position rises to lift the steel pipe, and the two ends of the steel pipe are respectively in place with the sealing rings 8 on the pipe head sealing seat 12 and the pipe tail sealing seat 13, and the hydraulic cylinder 5 extends to make the pipe head sealing seat 12 and the pipe tail sealing seat 13 firmly clamp the steel pipe 21 to be pressed;

[0046] 3) Before injecting water into the water pressure system 4 pipe network, close the drain valve 10, open the exhaust valve 22, and slowly increase the pressure during the water injection process. The pressure increase rate should be controlled at no more than 0.1MPa / minute. During the water injection, observe whether the steel pipe weld is leaking;

[0047] When the design working pressure of the steel pipe 21 to be pressurized is equal to or less than 1.0MPa, the water pressure strength test pressure should be 1.5 times the design working pressure and should not be less than 1.4MPa; when the system design working pressure is greater than 1.0MPa, the water pressure strength test pressure should be the working pressure plus 0.4MPa;

[0048] 4) When the water pressure system 4 reaches the test pressure, the pressure is stabilized for 30 to 45 minutes. The pipe network should have no leakage and no deformation, and the pressure drop should not be greater than 0.05 MPa. It is considered that the steel pipe 21 to be pressurized has no leakage;

[0049] 5) Open the drain valve 22 on the pipe head sealing seat 12 to drain all the water in the pressurized steel pipe;

[0050] 6) The hydraulic cylinder 5 retracts, the pipe head sealing seat 12 and the pipe tail sealing seat 13 respectively retreat to release the steel pipe, and the steel discharge flap 17 moves to push the pressed steel pipe to the discharge side track 3. The steel pipe rolls along the discharge side track to the buffer area, and the buffer flap 16 moves to keep the steel pipe in the buffer area until it is lifted away by the crane.

[0051] When the ambient temperature is lower than 5°C during the water pressure test, the water pressure system 4 needs to adopt a heating device as an anti-freezing measure.

[0052] Before the water pressure system is tested by water injection, a water pressure tightness test should be carried out after the water pressure strength test and pipe network flushing are qualified. The test pressure should be the design working pressure, and there should be no leakage after the pressure is stabilized for 24 hours.

[0053] Before the pressure test of the present invention, the pipe network and valves of the hydraulic system 4 need to be subjected to a water pressure strength test and an air pressure tightness test to ensure the accuracy of the test results. The steps are as follows:

[0054] 1) The water pressure strength test pressure is 1.5 times the design working pressure of the pipeline network; the air pressure tightness test pressure is the design working pressure;

[0055] 2) When conducting the water pressure strength test, the water temperature should not be lower than 5°C. After reaching the test pressure, the pressure should be stabilized for at least 1 minute, and there should be no deformation when visually observed;

[0056] 3) The air pressure tightness test should be carried out after the water pressure strength test. The test medium can be air or nitrogen. During the test, the test component should be placed in a water tank. After reaching the test pressure, the pressure should be stabilized for no less than 5 minutes, and no bubbles should be generated;

[0057] 4) After the component passes the test, it should be dried in time and all exposed interfaces should be sealed.

[0058] The embodiments described above are only specific examples selected to illustrate the purpose, technical solutions and beneficial effects of the present invention in detail, but should not limit the scope of protection of the invention. All modifications, equivalent substitutions and improvements made without violating the spirit and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A universal steel pipe pressure test device, the structure of which includes a pressure machine, a feed side track, a discharge side track and a hydraulic system. The pressure machine is arranged at the pressure position between the feed side track and the discharge side track, and the hydraulic system is connected to the pressure machine. Two V-shaped hydraulic brackets are arranged at the pressure position, one of the two V-shaped hydraulic brackets is located at the pipe head sealing seat side, and the other is located at the pipe tail sealing seat side. The V-shaped hydraulic bracket on the pipe tail sealing seat side is 10-20 mm higher than the V-shaped hydraulic bracket on the pipe head sealing seat side; the pressure machine includes a gantry, a pipe head sealing seat and a pipe tail sealing seat, the pipe head sealing seat and the pipe tail sealing seat are respectively connected to the two side columns of the gantry through a hydraulic cylinder and a vertical slide seat, and a plurality of sets of concentrically arranged sealing rings are respectively arranged on the pipe head sealing seat and the pipe tail sealing seat, and the sealing rings include a conical rubber seat ring and a lip-shaped Sealing ring, 3 to 4 metal flip bodies are evenly arranged in the circumferential direction inside the conical rubber seat ring, the cross-section of the metal flip body is L-shaped, including a bottom side, a long side and an inflection point, the bottom side is located in the conical rubber seat ring, the long side is located in the lip sealing ring, the bottom side is connected to the compression spring, the inflection point and the metal back plate are hinged by a pin, a drain pipe is provided on the lower side of each group of sealing rings of the pipe head sealing seat, and the drain valve is connected to the outside of the drain pipe; an exhaust pipe is provided on the upper side of each group of sealing rings of the pipe tail sealing seat, the inner side of the exhaust pipe is bent upward and opened at the high point of the inner wall of the steel pipe to be pressed, and the outer side of the exhaust pipe is connected to the exhaust valve; the size of a certain group of sealing rings matches the nominal diameter of a certain specification of steel pipe; the water pressure system includes a water pump, a water tank, a valve and a pipeline, the output end of the water pump is connected to the pipe tail sealing seat through a pipeline and the outlet is at the center of the pipe tail sealing seat.

2. The universal steel pipe pressure test device according to claim 1, characterized in that: A waiting area is provided on the feed side track, and 1 to 2 waiting flaps are provided between the tracks of the waiting area. One end of the waiting flap is connected to the hinge shaft, and the other end is connected to the piston end of the waiting action cylinder.

3. The universal steel pipe pressure test device according to claim 1, characterized in that: A buffer area is provided at the end of the discharge side track, and 1 to 2 buffer flaps are provided between the tracks of the buffer area. One end of the buffer flap is connected to the hinge shaft, and the other end is connected to the piston end of the buffer action cylinder.

4. The universal steel pipe pressure test device according to claim 1, characterized in that: The vertical slide is provided with a nut, which is matched with a ball screw. Both ends of the ball screw are connected to the columns of the gantry through bearing seats. The end of the ball screw is connected to a slide motor. The vertical slide and the column are also matched and connected through a dovetail groove guide rail.

5. The universal steel pipe pressure test device according to claim 1, characterized in that: The pressing position is provided with a steel tapping flap, one end of which is connected to the hinge shaft, and the other end is connected to the piston end of the steel tapping action cylinder.

6. An operating method of a universal steel pipe pressure test device, using the universal steel pipe pressure test device according to claim 1, characterized in that: The specific steps are as follows: 1) The steel pipe to be pressed is lifted by a crane to the waiting area, and the waiting flap moves, so that the steel pipe to be pressed in the waiting area rolls along the feed side track to the pressing position; 2) The V-shaped hydraulic bracket on the pressure-pressing position rises to lift the steel pipe to be pressed. The two ends of the steel pipe to be pressed are respectively in place with the sealing rings on the pipe head sealing seat and the pipe tail sealing seat. The hydraulic cylinder extends so that the pipe head sealing seat and the pipe tail sealing seat firmly clamp the steel pipe to be pressed; 3) Before injecting water into the water pressure system network, close the drain valve, open the exhaust valve, and slowly increase the pressure during the water injection process. The pressure increase rate should be controlled at no more than 0.1MPa / minute. During the water injection, observe whether the welds on the steel pipes to be pressurized are leaking; When the design working pressure of the steel pipe to be pressurized is equal to or less than 1.0MPa, the water pressure strength test pressure should be 1.5 times the design working pressure and should not be lower than 1.4MPa; when the system design working pressure is greater than 1.0MPa, the water pressure strength test pressure should be the working pressure plus 0.4MPa; 4) When the water pressure system reaches the test pressure, the pressure should be stabilized for 30 to 45 minutes. The pipe network should have no leakage or deformation, and the pressure drop should not be greater than 0.05 MPa. It is considered that the steel pipe to be pressurized has no leakage; 5) Open the drain valve on the pipe head sealing seat to drain all the water in the steel pipe to be pressurized; 6) The hydraulic cylinder retracts, and the pipe head sealing seat and the pipe tail sealing seat retreat respectively to release the steel pipe to be pressed. The steel discharge flap moves to push the pressed steel pipe to the discharge side track. The steel pipe rolls along the discharge side track to the buffer area, and the buffer flap moves to keep the steel pipe in the buffer area until it is lifted away by the crane.

7. The method for operating the universal steel pipe pressure test device according to claim 6, characterized in that: When the ambient temperature is lower than 5°C during the water pressure strength test, a heating device is used in the water pressure system as an anti-freezing measure.

8. The method for operating the universal steel pipe pressure test device according to claim 6, characterized in that: Before the water pressure system is subjected to water injection pressure test, a water pressure tightness test shall be carried out after the water pressure strength test and pipe network flushing are qualified. The test pressure shall be the design working pressure, and there shall be no leakage after the pressure is stabilized for 24 hours.

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