PE pipe flange strength test tool and method

Abstract

The invention discloses a PE pipe flange strength test tool and method, and relates to the technical field of ship construction, the PE pipe flange strength test tool comprises a base, and a stretching device and a jacking device arranged on the base; the stretching device comprises a left flange joint fixed on the base, a right flange joint which is arranged opposite to the left flange joint left and right and is arranged on the base in a sliding manner, and a sliding driving device for driving the right flange joint to slide left and right; the left flange joint, the PE pipe and the right flange joint define a sealed space; the left flange joint is provided with a water inlet pipe for communicating the airtight space with the outside, and the water inlet pipe is connected with water tightness test equipment; and the jacking device is arranged at the bottom of the PE pipe. The device effectively simulates the stress caused by temperature / hull deformation of the PE pipe in the ship operation process, detects whether the ship pipe leaks or not, and effectively verifies the influence of the vertical arch on the flange strength in the ship operation process, so that construction is carried out in advance, and ship delivery delay caused by later replacement and maintenance is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of shipbuilding, and in particular to a PE pipe flange strength test tool and method. Background Art

[0002] In recent years, PE pipes are increasingly used in ballast systems of large ships. Such system layouts all have a characteristic that they all have long straight pipe sections along the length of the ship and the main pipe diameter is large. Since the thermal linear expansion coefficient of PE pipes is large, expansion joints are generally not installed. Therefore, the stress caused by temperature / hull deformation is absorbed by the PE pipe itself, and the stress is relatively large.

[0003] The currently designed PE pipe flange strength test method generally adopts the GB / 15820-1995 method, but this method has the following problems: the pull-out test using a tensile gauge according to GB / 15820-1995 is only applicable to small-sized PE pipes; the specifications of the ship ballast main pipe are large, and the existing test equipment cannot be clamped, and cannot provide a large tensile force. If the equipment is customized, the cost is quite high; and the pull-out test equipment cannot perform a watertightness test on the pipe during the test, so it is impossible to verify whether the ship pipe leaks under the stress. In addition, the vertical arch during the operation of the ship affects the flange strength; and the current verification method can only verify the PE pipe flange strength during the trial stage, and whether the bolt preload meets the use requirements. If the PE pipe flange strength is not enough, or the bolt preload is insufficient, it is necessary to replace the PE pipe flange on site or increase the bolt preload, which will cause delays in ship delivery and affect the benefits of the shipyard. Summary of the invention

[0004] The purpose of the present invention is to provide a PE pipe flange strength test tool and method, which can effectively simulate the situation in which the PE pipe is subjected to stress caused by temperature / hull deformation during ship operation to detect whether the ship pipe is leaking, and at the same time effectively verify the influence of the vertical arch on the flange strength during the operation of the ship, so as to advance the construction and avoid the delay of ship delivery caused by later replacement and maintenance.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] The invention discloses a PE pipe flange strength test tool, comprising a base, a stretching device and a jacking device arranged on the base; the stretching device comprises a left flange joint fixed on the base, a right flange joint arranged opposite to the left flange joint and slidably installed on the base, and a sliding driving device driving the right flange joint to slide left and right; one end of a PE pipe to be tested is fixed on the left flange joint, and the other end is fixed on the right flange joint; the left flange joint, the PE pipe and the right flange joint form a closed space; a water inlet pipe connecting the closed space with the outside is arranged on the left flange joint, and the water inlet pipe is connected to a water tightness test device; the jacking device is arranged at the bottom of the PE pipe and is used for jacking the PE pipe upwards.

[0007] After adopting the above structure, the PE pipe to be tested is installed on the left flange joint and the right flange joint, and the right flange joint is driven to move to the right by the sliding drive device, so as to stretch the PE pipe to be tested, so as to simulate the stress stretching caused by temperature / hull deformation after the PE pipe is installed on the ship; the PE pipe is lifted from the bottom of the PE pipe by the lifting device, so as to simulate the influence of the flange strength caused by the mid-sagging and mid-arch of the ship after the PE pipe is installed on the ship; then, high-pressure water is introduced into the closed space surrounded by the left flange joint, the PE pipe and the right flange joint to detect whether the ship pipe is leaking, so as to replace the PE pipe flange in advance or increase the bolt preload according to the test results, so as to prevent the secondary rework of the PE pipe after it is installed on the ship, which causes delays in the construction period.

[0008] Preferably, a left mounting plate and a right mounting plate are relatively fixedly mounted on the base; the left flange joint is fixed on the left mounting plate, and the right flange joint is slidably mounted on the right mounting plate; a limit column is respectively arranged on the front and rear sides of the PE pipe on the base, and a slide bar is fixed between each limit column and the right mounting plate, the axial direction of the slide bar is in the left and right direction, and the right flange joint is slidably mounted on the slide bar. Through this design, the right flange joint can be guaranteed to slide smoothly.

[0009] Preferably, the sliding drive device includes a worm gear elevator and a stepper motor driving the worm gear elevator, and the output shaft of the worm gear elevator is fixed on the right flange joint. Through this design, the sliding distance of the right flange joint can be accurately controlled, thereby controlling the stretching distance of the PE pipe, so as to make the test data more accurate.

[0010] Preferably, two slide bars are fixed between each limit column and the right mounting plate, and the two slide bars are arranged in parallel up and down. Through this design, sufficient support points can be provided for the right flange joint, thereby reducing the deformation caused by the force of a single slide bar, and at the same time, the sliding stability of the right flange joint can be ensured.

[0011] Preferably, the lifting device includes a lifting platform installed on the base for moving up and down and a lifting drive device for driving the lifting platform to lift. Through this design, the lifting platform pushes the PE pipe upward from the bottom to bend, thereby simulating the sagging and arching state of the PE pipe.

[0012] Preferably, the lifting platform includes a V-shaped support frame; the PE pipe is supported on the front and rear inclined surfaces of the V-shaped support frame. Through this design, the contact area between the PE pipe and the lifting platform can be increased, the force on the PE pipe is balanced, and the deformation of the PE pipe is avoided.

[0013] Preferably, support wheels are rotatably mounted on the front and rear inclined surfaces of the V-shaped support frame, and the support wheels are supported on the bottom of the PE pipe and rotate in the left and right directions. This design avoids friction between the V-shaped support frame and the PE pipe during the lifting or stretching process, thereby preventing damage to the PE pipe.

[0014] Preferably, two lifting devices are provided, which are respectively located on the left and right sides of the PE pipe. Through this design, the PE pipe can be more stable in shape and more evenly stressed when simulating the sagging and arching state, thus avoiding damage to the PE pipe due to uneven stress.

[0015] A method for conducting an experiment using the above-mentioned PE pipe flange strength test tooling, S1: calculating the maximum deformation △L1 of the PE pipe caused by temperature difference; S2: calculating the maximum deformation △L2 and the sagging and cambering amount of the PE pipe in the ship length direction caused by the deformation of the hull during the operation of the ship; S3: making a PE pipe for the test, and clamping the flange of the PE pipe to the stretching device of the PE pipe flange strength test tooling; S4: stretching the PE pipe by the stretching device, the stretching length is △L, wherein △L=△L1+△L2; S5: lifting the PE pipe by the lifting device, so that the sagging and cambering amount of the PE pipe is consistent with the sagging and cambering amount calculated in S2; step S6: filling the water inlet pipe with water by the watertightness test equipment to perform a pressure tightness test to check whether the PE pipe has leakage.

[0016] By adopting the above method, it is possible to effectively simulate the situation in which the PE pipe is subjected to stress caused by temperature / hull deformation during ship operation, detect whether the ship pipe is leaking, and effectively verify the influence of the vertical arch on the flange strength during ship operation, so as to advance the construction and avoid delays in ship delivery caused by later replacement and maintenance.

[0017] Preferably, the calculation formula for the maximum deformation △L1 of the PE pipe of S1 is: △L1=△t*α*L; where △t is the highest temperature difference between the installation and use of the PE pipe calculated based on the temperature over the years; α is the linear expansion coefficient of the PE pipe; and L is the total length of the PE pipe. Through this design, the deformation of the PE pipe caused by temperature can be accurately calculated, thereby making the simulation data more accurate.

[0018] After adopting the above technical solution, the beneficial effects of the present invention are:

[0019] The present invention provides a PE pipe flange strength test tool and method to solve the technical problem in the prior art that the PE pipes in the ballast system of a large ship need to be reworked after being assembled on the ship because simulation experiments cannot be carried out in advance, which affects the construction period. The present invention effectively simulates the stress caused by temperature / hull deformation during the operation of the ship to detect whether the ship pipes are leaking, and effectively verifies the influence of the vertical arch on the flange strength during the operation of the ship, so as to advance the construction and avoid the delay of ship delivery caused by later replacement and maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of a PE pipe flange strength test tool and method of the present invention;

[0021] Figure 2 yes Figure 1 Schematic diagram of the tooling structure without PE pipe installed;

[0022] Figure 3 yes Figure 1 Side view of

[0023] Figure 4 It is a structural schematic diagram of the jacking device.

[0024] In the figure, 1. base, 11. limit column, 2. stretching device, 21. left flange joint, 211. left mounting plate, 22. right flange joint, 221. right mounting plate, 222. slide rod, 23. sliding drive device, 231. worm gear lift, 232. stepping motor, 3. lifting device, 31. lifting platform, 311. V-shaped support frame, 312. lifting drive device, 313. support wheel, 314. telescopic column, 4. PE pipe, 41. flange plate, 5. water inlet pipe. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings.

[0026] The orientations mentioned in this specification are based on the orientations of the PE pipe flange strength test tool and method of the present invention during normal operation, and do not limit the orientations during storage and transportation. They only represent relative positional relationships, not absolute positional relationships.

[0027] like Figure 1 , Figure 2 and Figure 3 As shown together, a PE pipe flange strength test tool includes a base 1, a stretching device 2 and a jacking device 3 arranged on the base 1.

[0028] The stretching device 2 includes a left flange joint 21 fixed on the base 1, a right flange joint 22 arranged opposite to the left flange joint 21 and slidably mounted on the base 1, and a sliding driving device 23 driving the right flange joint 22 to slide left and right; flanges 41 are fixed to the left and right ends of the PE pipe 4 to be tested, respectively, wherein the flange 41 at one end is fixed to the left flange joint 21, and the flange 41 at the other end is fixed to the right flange joint 22. The flange 41 is fixed to the left flange joint 21 / right flange joint 22 on the same side thereof by bolts, and the left flange joint 21, the PE pipe and the right flange joint 22 enclose a closed space.

[0029] The sliding installation method of the right flange joint 22 can be a variety of structures, such as a slide rail is set on the base 1, and a slider is fixedly installed on the right flange joint 22, and the slider is slidably installed in the slide rail to realize the sliding installation of the right flange joint 22.

[0030] In this embodiment, in order to facilitate the installation of the left flange joint 21 and the right flange joint 22, a left mounting plate 211 and a right mounting plate 221 are relatively fixedly installed on the base 1. In order to maintain the stability of the device, the four corners of the left mounting plate 211 and the right mounting plate 221 are connected by connecting rods to form a stable frame structure. The left flange joint 21 is fixed on the left mounting plate 211, and the right flange joint 22 is slidably installed on the right mounting plate 221. Among them, the sliding installation method of the right mounting plate 221 is as follows: a limit column 11 is respectively arranged on the front and rear sides of the PE pipe 4 on the base 1, and a slide bar 222 is fixed between each limit column 11 and the right mounting plate 221, and the axial direction of the slide bar 222 is the left and right direction. The right flange joint 22 is provided with a slide hole for the slide bar 222 to pass through. By sleeve-arranging the right flange joint 22 on the slide bar 222, the right flange joint 22 is slidably installed on the slide bar 222.

[0031] In order to make the sliding smoother, a sliding sleeve is installed in the sliding hole; further, in order to achieve better guidance for the sliding of the right flange joint 22, two sliding rods 222 are fixed between each limit column 11 and the right mounting plate 221 in this embodiment, and the two sliding rods 222 are arranged parallel to each other up and down, so as to ensure that the right flange joint 22 is more stable.

[0032] The sliding drive device 23 can be an electric cylinder or a pneumatic cylinder or an electric push rod. In order to achieve precise control of stretching, the sliding drive device 23 in this embodiment includes a worm gear lift 231 and a stepper motor 232 driving the worm gear lift 231. The output shaft of the worm gear lift 231 is fixed on the right flange joint 22. The operation of the stepper motor 232 drives the movement of the worm gear lift 231, thereby controlling the right flange joint 22 to slide left and right, thereby achieving stretching of the PE pipe 4. The left flange joint 21 is provided with a water inlet pipe 5 connecting the closed space with the outside, and the water inlet pipe 5 is connected to the water tightness test equipment.

[0033] The lifting device 3 is arranged at the bottom of the PE pipe 4, and is used to lift the PE pipe 4 upward. The lifting device 3 includes a lifting platform 31 installed on the base 1 and located at the bottom of the PE pipe 4 to be tested, and a lifting drive device 312 that drives the lifting platform 31 to rise and fall. The lifting drive device 312 can be a hydraulic lifting device, and the lifting platform 31 is driven to rise and fall by the lifting drive device 312; through the lifting and falling of the lifting platform 31, the middle of the PE pipe 4 is driven to bulge upward, thereby simulating the state of the middle sagging and middle arching during the navigation of the ship. In order to make the middle sagging and middle arching shape of the PE pipe 4 more stable, two lifting platforms 31 are provided in this embodiment, which are respectively located on the left and right sides of the PE pipe 4.

[0034] like Figure 4 As shown, the lifting platform 31 includes a V-shaped support frame 311; the PE pipe 4 is clamped between the front and rear inclined surfaces of the V-shaped support frame 311, and the V-shaped support frame 311 is welded by steel pipes.

[0035] In order to prevent the V-shaped support frame 311 from causing wear to the PE pipe 4 during stretching and jacking, support wheels 313 are rotatably installed on the front and rear inclined surfaces of the V-shaped support frame 311. The support wheels 313 are supported at the bottom of the PE pipe 4 and rotate in the left and right direction.

[0036] In order to make the lifting platform 31 more stable, telescopic columns 314 are arranged on the front and rear sides of the V-shaped support frame 311 . The fixed end of the telescopic column 314 is fixed on the base 1 , and the telescopic end of the telescopic column 314 is fixed on the V-shaped support frame 311 .

[0037] A method for conducting an experiment using the above-mentioned PE pipe flange strength test tool comprises the following steps:

[0038] S1: Calculate the maximum deformation of the PE pipe △L1 caused by temperature difference;

[0039] According to the temperature of the area where the shipyard is located over the years, the highest temperature difference △t from the installation of the PE pipe to the use stage is calculated, and the maximum deformation △L1 of the PE pipe caused by temperature is calculated; the calculation formula of △L1 is: △L1=△t*α*L, where α is the linear expansion coefficient of the PE pipe, which can be found in the PE pipe material certificate; the linear expansion coefficient refers to the linear expansion of the unit length of the PE pipe along its length direction when the temperature changes by 1°C; the specific value is 1.1 to 1.3 multiplied by 10 to the negative fourth power per Kelvin (10^-4 / K), which means that if the temperature rises by 1K (or 1°C), each meter of PE pipe will increase by about 0.00011 to 0.00013 meters (i.e. 1.1 to 1.3 microns) due to thermal expansion. L is the total length of the PE pipe 4.

[0040] S2: Calculate the maximum deformation △L2 and sagging amount of the PE pipe in the ship's length direction caused by the hull structure during the operation of the ship;

[0041] Through structural finite element analysis (software analysis, analysis software includes PKPM, 3D3S, MTS, MST, Tongji Venus, ETABS, SAP2000, SAFE, PERFORM-3D, MIDAS, STAAD PRO, ROBOT, EASY, FORTEN, ANSYS, ABAQUS, NASTRAN, MARC, LS-DYNA, etc.), the maximum deformation △L2 in the length direction of the PE pipe caused by the hull structure during the operation of the ship and the maximum structural sagging and arching of the PE pipe are calculated.

[0042] S3: Prepare a PE pipe 4 for testing, and clamp the flange of the PE pipe 4 onto the tensile device 2 of the PE pipe flange strength test tooling;

[0043] Make a PE pipe for the test, assemble the PE pipe 4 with the above-mentioned PE pipe flange strength test tooling; it should be noted that the length L+△L1+△L2 should be less than the maximum left-right distance between the left flange joint 21 and the right flange joint 22. The flange on one side of the PE pipe 4 is fixed to the left flange joint 21 with bolts, and the flange on the other side is fixed to the right flange joint 22 with studs. The PE pipe includes a plurality of pipes that are connected to each other on the left and right sides, and the adjacent pipes are fixedly connected by flanges, and a sealing ring is clamped between them.

[0044] S4: The PE tube is stretched by the stretching device 2, and the stretching length is △L, wherein △L=△L1+△L2.

[0045] The right flange joint 22 is driven to slide rightward by the sliding drive device 23 , thereby achieving the stretching of the PE pipe 4 .

[0046] S5: The PE pipe is lifted by the lifting device 3 so that the sagging and arching amount of the PE pipe is consistent with the sagging and arching amount calculated in S2.

[0047] Step S6: Fill the water inlet pipe 5 with water through a water tightness test device to perform a pressure tightness test to check whether the PE pipe has any leakage.

[0048] Carry out a tightness test on the PE pipe 4 at 1.5 times the design pressure for 1 hour to check whether there is any leakage in the pipeline.

[0049] The present invention provides a PE pipe flange strength test tool and method to solve the technical problem in the prior art that the PE pipes in the ballast system of a large ship need to be reworked after being assembled on the ship because simulation experiments cannot be carried out in advance, which affects the construction period. The present invention effectively simulates the stress caused by temperature / hull deformation during the operation of the ship to detect whether the ship pipes are leaking, and effectively verifies the influence of the vertical arch on the flange strength during the operation of the ship, so as to advance the construction and avoid the delay of ship delivery caused by later replacement and maintenance.

[0050] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A PE pipe flange strength test tool, characterized by: It comprises a base, a stretching device and a lifting device arranged on the base; The stretching device comprises a left flange joint fixed on the base, a right flange joint arranged opposite to the left flange joint and slidably mounted on the base, and a sliding drive device driving the right flange joint to slide left and right; one end of the PE pipe to be tested is fixed on the left flange joint, and the other end is fixed on the right flange joint; the left flange joint, the PE pipe and the right flange joint form a closed space; the left flange joint is provided with a water inlet pipe connecting the closed space with the outside, and the water inlet pipe is connected to the water tightness test equipment; The lifting device is arranged at the bottom of the PE pipe and is used for lifting the PE pipe upward.

2. A PE pipe flange strength test tool according to claim 1, characterized in that: A left mounting plate and a right mounting plate are relatively fixedly installed on the base; the left flange joint is fixed on the left mounting plate, and the right flange joint is slidably installed on the right mounting plate; a limit column is respectively arranged on the front and rear sides of the PE pipe on the base, and a sliding rod is fixed between each limit column and the right mounting plate, the axial direction of the sliding rod is left and right, and the right flange joint is slidably installed on the sliding rod.

3. A PE pipe flange strength test tool according to claim 1, characterized in that: The sliding drive device comprises a worm gear elevator and a stepping motor for driving the worm gear elevator to operate, and the output shaft of the worm gear elevator is fixed on the right flange joint.

4. A PE pipe flange strength test tool according to claim 2, characterized in that: Two sliding rods are fixed between each of the limiting columns and the right mounting plate, and the two sliding rods are arranged in parallel up and down.

5. A PE pipe flange strength test tool according to claim 1, characterized in that: The lifting device comprises a lifting platform installed on the base for moving up and down and a lifting driving device for driving the lifting platform to move up and down.

6. A PE pipe flange strength test tool according to claim 5, characterized in that: The lifting platform comprises a V-shaped support frame; the PE pipe is supported on the front and rear inclined surfaces of the V-shaped support frame.

7. A PE pipe flange strength test tool according to claim 6, characterized in that: Support wheels are rotatably mounted on the front and rear inclined surfaces of the V-shaped support frame. The support wheels are supported on the bottom of the PE pipe and rotate in the left and right directions.

8. A PE pipe flange strength test tool according to claim 5, characterized in that: The jacking devices are provided with two, which are respectively located on the left and right sides of the PE pipe.

9. A method for conducting an experiment using the PE pipe flange strength test tool as described in any one of claims 1 to 8, characterized in that: The following steps are involved: S1: Calculate the maximum deformation of the PE pipe △L1 caused by temperature difference; S2: Calculate the maximum deformation △L2 and sagging amount of the PE pipe in the ship's length direction caused by the deformation of the hull during the operation of the ship; S3: Prepare a PE pipe for testing, and clamp the flange of the PE pipe to the tensile device of the PE pipe flange strength test tooling; S4: stretching the PE tube by a stretching device, the stretching length is △L, where △L=△L1+△L2; S5: The PE pipe is lifted by the lifting device to make the sagging and arching amount of the PE pipe consistent with the sagging and arching amount calculated in S2; Step S6: Fill the water inlet pipe with water through a water tightness test device to perform a pressure tightness test to check whether the PE pipe has any leakage.

10. A method for conducting an experiment using a PE pipe flange strength test tool according to claim 9, characterized in that: The calculation formula for the maximum deformation △L1 of the PE pipe of S1 is: △L1=△t*α*L; wherein △t is the highest temperature difference from the installation of the PE pipe to the use stage calculated based on the temperature over the years; α is the linear expansion coefficient of the PE pipe; and L is the total length of the PE pipe.

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