Piping method for spring-supported pump

Abstract

The invention discloses a piping method for a spring-supported pump, which comprises the following steps of: firstly, adjusting the axis, the center line and the levelness of a pump body of the spring-supported pump, centering a shaft of a coupler between a motor and the pump body of the spring-supported pump, and connecting a pipeline flange of an upper pipeline with a flange of a heat exchanger; a temporary blind plate gasket is installed between the pipeline flange and the pump body flange, water is injected into the concentric reducing pipe, protective argon is introduced into the upper pipeline, and a welding seam between the upper pipeline and the concentric reducing pipe is sealed through a paper adhesive tape; welding a welding seam between the upper pipeline and the concentric reducing pipe; after welding is completed, a bolt between a pipeline flange of the concentric reducing pipe and a pump body flange of the spring supporting type pump is loosened, water in the concentric reducing pipe is discharged, and the temporary blind plate gasket is taken down; the formal gasket between the pipeline flange of the concentric reducing pipe and the pump body flange of the spring supporting type pump is replaced, and the bolt is fastened. By means of the method for controlling welding deformation, the stress between equipment and the pipeline is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of petrochemical pipeline installation, and more particularly, to a piping method for a spring-supported pump. Background Art

[0002] During the pipeline welding in petrochemical projects, due to local high-temperature heating, the temperature distribution on the welded parts is uneven, which ultimately leads to the generation of welding stress and deformation inside the structure. Welding deformation also makes it difficult for the shape and dimensional accuracy of the structure to meet the technical requirements, directly affecting the installation quality and service performance. Therefore, the quality control technology for pipeline installation is crucial.

[0003] The reactions of many chemical materials exist in various forms, often requiring reactions in the solid, gas, and liquid states, and achieving the predetermined reaction conditions through changes in temperature and pressure. The spring-supported pump described in the present invention belongs to a type of eddy current pump, which can achieve three-state transportation through a special impeller design and can absorb the thermal expansion caused by high temperature. However, the outlet of such pumps is often directly connected to a heat exchanger. Therefore, the pipeline installation stress has a great impact on the leveling and alignment of the spring-supported pump and the quality of the coupling alignment. Improper control will seriously affect the overall operation of its system. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a piping method for a spring-supported pump, which controls the adverse effects of the residual stress caused by welding deformation of the process pipelines at the inlet and outlet of dynamic equipment on the operation of the petrochemical system, and achieves the purpose of improving the stability of chemical production.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is as follows: A piping method for a spring-supported pump, the spring-supported pump includes a pump body, an inlet and outlet is provided on one side of the pump body, the top of the spring-supported pump outlet is connected to a heat exchanger through a pipeline, and the pipeline includes an upper pipeline and a concentric reducer at the lower part, including: Step 1, adjust the axis, center line and levelness of the spring-supported pump body and perform shaft alignment on the coupling between the motor and the spring-supported pump body; Step 2, connect the pipeline flange of the upper pipeline to the heat exchanger flange; Step 3, align the bolt holes of the pipeline flange of the concentric reducer with the pump body flange of the spring-supported pump, install a temporary blind gasket between the pipeline flange and the pump body flange, and then insert bolts into the corresponding bolt holes; Step 4, inject water into the concentric reducer, introduce protective argon into the upper pipeline, and seal the weld between the upper pipeline and the concentric reducer with paper tape; Step 5, weld the weld between the upper pipeline and the concentric reducer; Step 6: After welding is completed, loosen the bolts between the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump, drain the water inside the concentric reducer, and remove the temporary blind flange gasket. Step 7: Replace the official gasket between the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump and tighten the bolts.

[0006] Further, in Step 1, taking the outlet of the spring-supported pump as the reference, use a laser theodolite to adjust the center line positions of the outlet of the spring-supported pump and the heat exchanger to be consistent in both the vertical and horizontal directions; after adjustment, use a frame level to perform fine alignment of the installation of the pump body of the spring-supported pump with the reference of the finished machining surface of the flange at the outlet of the spring-supported pump; use a dial indicator to perform shaft alignment on the coupling between the motor and the pump body of the spring-supported pump.

[0007] Further, in Step 1, when performing fine alignment of the installation of the pump body, the longitudinal allowable deviation is within ±0.05 mm / m, and the transverse allowable deviation is ±0.1 mm / m.

[0008] Further, in Step 1, when performing shaft alignment on the coupling, the allowable deviation is ±0.03 mm.

[0009] Further, in Step 2, hang a chain hoist on both sides and the front side of the support of the heat exchanger to connect the upper pipeline, and use the chain hoist to connect the pipe flange of the upper pipeline and the heat exchanger flange.

[0010] Further, in Step 4, the water injected into the concentric reducer is demineralized water with a chloride ion content ≤ 25 ppm.

[0011] Further, in Step 4, the water level inside the concentric reducer is 30 mm below the weld.

[0012] Further, in Step 5, before welding, use a stainless steel positioning plate of the same material to position and fix the pipelines on both sides of the weld.

[0013] Further, in Step 5, during welding, place a frame level on the finished machining surface of the motor support, and install a dial indicator at the coupling to observe the changes in the key parts of the pump body during the pipeline welding process.

[0014] Further, in Step 7, before replacing the official gasket, first measure and accept the distance between the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump, the flatness of the flange, and the vertical and horizontal center lines.

[0015] The piping installation of spring-supported pumps must follow a series of key principles to ensure the stable operation and efficient performance of the pump system. The first principle is to reduce the additional stress of the pipeline on the pump inlet and outlet to avoid damage to the pump body or shortening of its service life due to stress concentration. According to the technical solution provided by the present invention, by reasonably selecting a method for controlling welding deformation when installing the upper pipeline of the spring-supported pump, during the installation of the pipeline between the pump outlet and the heat exchanger, the method for controlling welding deformation is used to calculate the thermal expansion of the pipeline, successfully control the welding deformation of the stainless steel pipeline, reduce the stress between the equipment and the pipeline, speed up the progress of pipeline installation and equipment single-machine trial run, improve the service life of the equipment, and ensure the stability of the later system operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings herein are used to provide further explanation of the present invention and constitute a part of this application. The illustrative embodiments of the present invention and their description are used to explain the present invention and do not constitute improper limitations on the present invention.

[0017] Figure 1 It is a schematic structural diagram of a spring-supported pump, a heat exchanger, an argon-filling protection device, etc. involved in the piping method of the present invention; Figure 2 It is a schematic diagram of local welding of the present invention; Figure 3 It is a schematic diagram of the centering of the coupling of the present invention.

[0018] In the figure: 1 is the pump body, 1-1 is the pump body flange, 1-2 is the pump body spring leg, 1-3 is the spring leg pad, 1-4 is the foundation anchor plate, 1-4 is the motor, and 1-5 is the coupling; 2 is a pipeline, 2-1 is a temporary blind plate gasket, 2-2 is a pipeline flange, 2-3 is a bolt, 2-4 is a paper tape, 2-5 is an argon filling inlet, 2-6 is a protective argon gas pipe, 2-7 is a gas cylinder, 2-8 is a frame level, 2-9 is desalted water, 2-10 is a dial indicator, 2-11 is an upper pipeline, and 2-12 is a concentric reducer.

[0019] 3 is a heat exchanger, and 3-1 is a heat exchanger flange. DETAILED DESCRIPTION

[0020] In order to make those skilled in the art better understand the present invention, the present invention is further clearly and completely described below in conjunction with the accompanying drawings and embodiments. It should be noted that, in the absence of conflict, the features in the embodiments and examples of this application can be combined with each other.

[0021] like Figure 1 and Figure 2As shown in the figure, a typical embodiment of the present invention relates to a spring-supported pump, which includes a pump body 1. An inlet and outlet is provided on one side of the pump body 1, and a motor is provided on the other side of the pump body 1. The top of the outlet of the spring-supported pump is connected to a heat exchanger 3 through a pipeline. The pipeline 2 includes an upper pipeline 2-11 and a lower concentric reducer 2-12.

[0022] The pipeline 2 is installed directly above the outlet of the spring-supported pump. Four foundation anchor plates 1-4 for installing equipment are embedded in the upper surface of the pump foundation. The pump body 1 is supported on 4 sets of pump body spring legs 1-2, and there is a spring leg backing plate 1-3 at the bottom of the pump body spring legs 1-2. The spring leg backing plate 1-3 is in direct contact with the foundation anchor plate 1-4. The requirement for the levelness of the installation of the foundation anchor plate 1-4 is relatively high, and the allowable deviation range is controlled within 0.1 mm.

[0023] The piping method of the spring-supported pump provided in this embodiment includes the following steps 1 to 7.

[0024] Step 1: Adjust the axis, center line and levelness of the pump body 1 of the spring-supported pump, and perform shaft alignment on the coupling 1-5 between the motor 1-4 and the pump body 1 of the spring-supported pump.

[0025] Taking the outlet of the spring-supported pump as the reference, use a laser theodolite to adjust the center line positions of the outlet of the spring-supported pump and the heat exchanger to be consistent in both the vertical and horizontal directions. After adjustment, use a frame level to perform fine alignment of the installation of the pump body of the spring-supported pump with the finished machining surface of the flange at the outlet of the spring-supported pump. The longitudinal allowable deviation is within ±0.05 mm / m, and the transverse allowable deviation is ±0.1 mm / m. Use a dial indicator to perform shaft alignment on the coupling between the motor and the pump body of the spring-supported pump, and the allowable deviation is ±0.03 mm.

[0026] Step 2: Connect the pipeline flange 2-2 of the upper pipeline 2-11 to the heat exchanger flange 3-1.

[0027] Relatively specifically, after all the inspections of the adjustment of the pump body axis, center line, levelness, and coupling alignment are qualified, first hang a chain hoist on both sides and the front side of the support steel structure of the heat exchanger 3 to connect the upper pipeline 2-11. Before installation, carefully check that the flange sealing surface has no damage and defects, and use a tetrafluoroethylene plate to protect the sealing surface to ensure good sealing and prevent damage to the sealing surface during the hoisting process. Use the oblique translation method to install the prefabricated section of the upper pipeline 2-11 in place, and tighten the bolts 2-3 between the heat exchanger 3 and the pipeline flange 2-2.

[0028] Step 3: Align the bolt holes of the pipeline flange 2-2 of the concentric reducer 2-12 with the pump body flange 1-1 of the spring-supported pump, install a temporary blind gasket 2-1 between the pipeline flange 2-2 and the pump body flange 1-1, and then insert bolts 2-3 into the corresponding bolt holes.

[0029] In this step, 4 bolts 2-3 inserted need to be tightened diagonally for centering guidance and cannot bear the weight of the upper pipeline 2-11, and all the inserted bolts 2-3 can be loosened freely.

[0030] Before inserting the bolts 2-3, install the temporary blind flange gasket 2-1 first. The temporary blind flange gasket 2-1 uses a tetrafluoroethylene plate with the same thickness as the formal gasket.

[0031] Step 4: Inject water into the concentric reducer 2-12, connect protective argon gas into the upper pipeline 2-11, and seal the weld between the upper pipeline 2-11 and the concentric reducer 2-12 with paper tape 2-4.

[0032] After the installation of the bolts 2-3 between the pipeline flange 2-2 of the concentric reducer 2-12 and the pump body flange 1-1 of the spring-supported pump is completed, as Figure 2 shown, inject water into the concentric reducer 2-12. Since the pipeline is made of stainless steel, the water quality must be demineralized water with a chloride ion content ≤ 25 ppm, and the liquid level is 30 mm below the weld to achieve the effect of cooling during the welding process.

[0033] As Figure 1 shown, the argon gas shielded backing welding device mainly includes a protective argon gas pipe 2-6 and a gas cylinder 2-7. The pressure gauge flange port on the side of the upper pipeline 2-11 serves as the argon gas charging inlet 2-5.

[0034] Connect the protective argon gas pipe 2-6 to the argon gas charging inlet 2-5, seal it with high-density sponge, and seal the weld with paper tape 2-4 to prevent the leakage of argon gas during welding, which may lead to welding defects caused by the failure of argon gas shielding, and create conditions for the argon gas shielding of the subsequent pipeline backing welding.

[0035] Step 5: Weld the weld between the upper pipeline 2-11 and the concentric reducer 2-12.

[0036] The argon gas in argon arc welding only plays a role in gas shielding and is very sensitive to oil, rust and other contaminants on the surface of the weldment and the filler metal. If not cleaned properly, defects such as pores and inclusions are likely to occur in the weld. Before welding, it must be carefully cleaned, and the grease, paint, coating on the groove surface and its inner and outer walls of the weldment, as well as the lubricant, oxide film and rust used in processing, etc., within 15 m~20 mm on each surface must be completely removed to make it show metallic luster. The cleaning requirements for the weldment are strict, and welding should be carried out as soon as possible after cleaning. Argon arc welding has relatively high requirements for the purity of argon gas, and the required purity is not less than 99.99%. High-purity argon gas can ensure the welding quality, improve the welding efficiency, and reduce the occurrence of pores.

[0037] Before welding, use stainless steel positioning plates of the same material to accurately position and fix the pipes on both sides of the weld to ensure that the pipes are in the correct position. After welding is completed, the stainless steel positioning plates should be promptly cut and polished, and PT inspection should be carried out to ensure the construction quality. Before this process is carried out, the fitter team should be notified to prepare personnel and tools and cooperate with the installation to ensure the smooth progress of stress-free pipe installation.

[0038] During welding, place a frame level 2-8 with an accuracy of 0.03 mm on the upper surface of the finish-machined surface of the pump body motor support, and install a dial indicator 2-10 at the coupling to observe the changes in the key parts of the pump body during the pipe welding process, so that the welding process can be adjusted in a timely manner according to the data changes of the frame level during welding. Among them, it is necessary to ensure that the initial data meets the specification requirements.

[0039] During the welding process, controlling the welding parameters is the key to preventing deformation. Two welders symmetrically use argon arc welding for backing, first spot-welding to fix the weld joint, and the positioning welding uses similar welding wires and processes as the formal welding. The length of the positioning weld is 10-15 mm, the reinforcement height is 2-3 mm, and there are 4 fixed positioning points. The positioning weld should ensure full penetration and no defects. Both ends of the positioning weld should be processed into a slope shape to facilitate the joint. When performing the formal backing weld, select appropriate welding current, voltage, and welding speed. During welding, the welding current should be adjusted as low as possible, and the welding speed should be increased as much as possible to reduce the welding line energy. During welding, the swing amplitude of the handle should be as small as possible. These measures can all reduce welding deformation. While ensuring the quality of the welded joint, minimize the thermal impact on the pipe. Select a smaller welding current and a faster welding speed to control the welding deformation of the stainless steel pipe.

[0040] To reduce the welding deformation of the pipe, argon arc welding is also used for filling and surfacing welding. During welding, the fitter observes the radial and axial displacements of the dial indicator on the coupling and the changes in the frame level at the same time. Once any deviation is found, measures should be taken immediately, stop welding on the side with a large deviation, and use the welding method in the opposite diagonal direction to restore the shape and size of the pipe, achieving an anti-deformation effect to bring it within the allowable installation deviation range of the pump body.

[0041] Step Six, after welding is completed, loosen the bolts 2-3 between the pipe flange 2-2 of the concentric reducer 2-12 and the pump body flange 1-1 of the spring-supported pump, drain the water inside the concentric reducer 2-12, and remove the temporary blind flange gasket 2-1.

[0042] After all the welds are completed, check the appearance quality of the welds, there are no sand holes and undercuts, and the weld reinforcement meets the specification requirements. After the welds are completely cooled, pickle and passivate the welds and conduct non-destructive testing.

[0043] After passing the inspection, slowly loosen the bolts 2-3 between the pipeline flange 2-2 and the pump body flange 1-1, drain the internal demineralized water, remove the temporary blind flange gasket 2-1, and measure and accept the distance between the flanges, the flatness of the flanges, and the longitudinal and transverse centerlines. Use a feeler gauge to measure the distance and non-parallelism between the flanges, and measure the deviation of the longitudinal and transverse centers symmetrically at four points. Check that the bolts inserted into the screw holes can freely penetrate without jamming. The acceptance standard is that the distance between the two flanges is 4 mm. Since the pump speed is greater than 6000 r / min, the non-parallelism of the two flanges is not greater than 0.1 mm; the concentricity deviation of the two flanges not only satisfies the free movement of the bolts in the bolt holes, but also satisfies being less than or equal to 0.2 mm.

[0044] Step 7: Replace the formal gasket between the pipeline flange 2-2 of the concentric reducer 2-12 and the pump body flange 1-1 of the spring support type pump and tighten the bolts 2-3. Before adding the formal gasket, check that the sealing surfaces of the two flanges and the gasket are free of damage and defects.

[0045] The scope of protection required by the present invention is not limited to the above specific embodiments. For those skilled in the art, the present invention can have various deformations and modifications. Any modification, improvement, and equivalent replacement made within the concept and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A piping method for a spring-supported pump, the spring-supported pump comprising a pump body, an inlet and outlet being provided on one side of the pump body, the top of the outlet of the spring-supported pump being connected to a heat exchanger through a pipeline, the pipeline comprising an upper pipeline and a concentric reducer at the lower part, characterized in that, Including: Step 1: Adjust the axis, center line and levelness of the spring-supported pump body, and perform shaft alignment on the coupling between the motor and the pump body of the spring-supported pump. Step 2: Connect the pipe flange of the upper pipe to the heat exchanger flange. Step 3: Align the center of the screw holes of the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump, install a temporary blind flange gasket between the pipe flange and the pump body flange, and then insert bolts into the corresponding screw holes. Step 4: Inject water into the concentric reducer, connect protective argon gas to the upper pipe, and seal the weld between the upper pipe and the concentric reducer with paper tape. Step 5: Weld the weld between the upper pipe and the concentric reducer. Step 6: After welding, loosen the bolts between the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump, drain the water inside the concentric reducer, and remove the temporary blind flange gasket. Step 7: Replace the formal gasket between the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump and tighten the bolts.

2. The piping method of the spring-supported pump according to claim 1, characterized in that: In Step 1, taking the outlet of the spring-supported pump as the reference, use a laser theodolite to adjust the center line positions of the outlet of the spring-supported pump and the heat exchanger to be consistent in both the vertical and horizontal directions; after adjustment, use a frame level to perform fine alignment of the installation of the pump body of the spring-supported pump with the reference of the precision machined surface of the flange at the outlet of the spring-supported pump; use a dial indicator to perform shaft alignment on the coupling between the motor and the pump body of the spring-supported pump.

3. The piping method of the spring-supported pump according to claim 2, characterized in that: In Step 1, when performing fine alignment of the installation of the pump body, the longitudinal allowable deviation is within ±0.05 mm / m, and the transverse allowable deviation is ±0.1 mm / m.

4. The piping method of the spring-supported pump according to claim 2 or 3, characterized in that: In Step 1, when performing shaft alignment on the coupling, the allowable deviation is ±0.03 mm.

5. The piping method of the spring-supported pump according to claim 4, characterized in that: In Step 2, hang a chain block on each side and the front side of the support of the heat exchanger to connect the upper pipe, and use the chain block to connect the pipe flange of the upper pipe to the heat exchanger flange.

6. The piping method of the spring-supported pump according to claim 1 or 5, characterized in that: In Step 4, the water injected into the concentric reducer is demineralized water with a chloride ion content ≤ 25 ppm.

7. The piping method of the spring-supported pump according to claim 6, characterized in that: In Step 4, the water level inside the concentric reducer is 30 mm below the weld.

8. The piping method of the spring-supported pump according to claim 1 or 7, characterized in that: In Step 5, before welding, use a stainless steel positioning plate of the same material to position and fix the pipes on both sides of the weld.

9. The piping method of the spring-supported pump according to claim 8, characterized in that: In Step 5, during welding, place a frame level on the precision machined surface of the motor support, install a dial indicator at the coupling, and observe the changes in the key parts of the pump body during the pipe welding process.

10. The piping method of the spring-supported pump according to claim 1 or 9, characterized in that: In Step 7, before replacing the formal gasket, first measure and accept the distance, flange flatness, and vertical and horizontal center lines between the pipe flange of the concentric reducer and the pump body flange of the spring-supported pump.

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