Piping method for spring supported pump

Abstract

The application discloses a piping method of a spring support type pump, which comprises the following steps: firstly, adjusting the axis, center line and levelness of a pump body of the spring support type pump, and performing shaft alignment on a coupling between a motor and the pump body of the spring support type pump; connecting a pipeline flange of an upper pipeline with a heat exchanger flange; installing a temporary blind plate gasket between the pipeline flange and a pump body flange, injecting water into a concentric reducing pipe, connecting protective argon into the upper pipeline, and sealing a welding seam between the upper pipeline and the concentric reducing pipe by using a paper adhesive tape; welding the welding seam between the upper pipeline and the concentric reducing pipe; after the welding is completed, loosening the bolts between the pipeline flange of the concentric reducing pipe and the pump body flange of the spring support type pump, draining the water in the concentric reducing pipe, and removing the temporary blind plate gasket; and replacing formal gaskets between the pipeline flange of the concentric reducing pipe and the pump body flange of the spring support type pump and fastening the bolts. The application reduces the stress between the equipment and the pipeline by controlling the welding deformation method.

Description

Technical Field

[0001] This invention relates to the field of petrochemical pipeline installation technology, and more specifically, to a piping method for a spring-supported pump. Background Technology

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

[0003] Many chemical reactions occur in multiple forms, often requiring solid, gas, and liquid states, and are achieved through changes in temperature and pressure to reach predetermined reaction conditions. The spring-supported pump described in this invention is a type of vortex pump. Through a special impeller design, it can achieve three-state transport and absorb the thermal expansion caused by high temperatures. However, the outlet of this type of pump is often directly connected to a heat exchanger. Therefore, the pipeline installation stress has a significant impact on the leveling, alignment, and coupling alignment quality of the spring-supported pump. Improper control can seriously affect the overall system operation. 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, thereby controlling the adverse effects of residual stress caused by welding deformation in the inlet and outlet process pipelines of the control equipment on the operation of the petrochemical system, and achieving the goal 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:

[0006] A piping method for a spring-supported pump, the spring-supported pump including a pump body, with an inlet and outlet on one side of the pump body, and the top of the spring-supported pump outlet connected to a heat exchanger via a pipe, the pipe including an upper pipe and a lower concentric reducer, comprising:

[0007] Step 1: Adjust the axis, centerline, and level of the spring-supported pump body, and align the coupling between the motor and the pump body.

[0008] Step 2: Connect the pipe flange of the upper pipe to the heat exchanger flange;

[0009] Step 3: Align the bolt hole center of the pipe flange of the concentric reducer with the bolt hole center of 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 bolt holes.

[0010] Step 4: Inject water into the concentric reducer, introduce protective argon gas into the upper pipe, and seal the weld between the upper pipe and the concentric reducer with paper tape.

[0011] Step 5: Weld the weld between the upper pipe and the concentric reducer;

[0012] 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.

[0013] Step 7: Replace the gasket between the concentric reducer flange and the spring-supported pump body flange and tighten the bolts.

[0014] Furthermore, in step one, using the outlet of the spring-supported pump as a reference, a laser theodolite is used to adjust the position of the spring-supported pump outlet and the center line of the heat exchanger in both longitudinal and transverse directions; after adjustment, a frame level is used to install and precisely align the pump body of the spring-supported pump using the precision-machined flange surface of the spring-supported pump outlet as a reference; a dial indicator is used to align the coupling between the motor and the pump body of the spring-supported pump.

[0015] Furthermore, in step one, when the pump body is installed and precisely aligned, the longitudinal allowable deviation is within ±0.05mm / m, and the lateral allowable deviation is within ±0.1mm / m.

[0016] Furthermore, in step one, when the coupling is aligned with the shaft, the allowable deviation is ±0.03mm.

[0017] Furthermore, in step two, a hand-operated hoist is hung on both sides and the front side of the heat exchanger support to connect the upper pipe, and the pipe flange of the upper pipe is connected to the heat exchanger flange using the hand-operated hoist.

[0018] Furthermore, in step four, the water injected into the concentric reducer is desalinated water with a chloride ion content ≤25ppm.

[0019] Furthermore, in step four, the water level inside the concentric reducer is raised to 30mm below the weld seam.

[0020] Furthermore, in step five, before welding, stainless steel positioning plates of the same material are used to position and fix the pipes on both sides of the weld.

[0021] Furthermore, in step five, during welding, a frame level is placed on the precision-machined surface of the motor bracket, and a dial indicator is set up at the coupling to observe the changes in key parts of the pump body during the pipeline welding process.

[0022] Furthermore, in step seven, before replacing the formal gasket, 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 longitudinal and transverse center lines are measured and accepted.

[0023] The piping installation of spring-supported pumps must adhere to a series of key principles to ensure the stable operation and high efficiency of the pump system. The primary principle is to reduce the additional stress on the pump inlet and outlet pipes, avoiding pump damage or shortened service life due to stress concentration. According to the technical solution provided by this invention, by rationally selecting a method to control welding deformation during the installation of the upper piping of the spring-supported pump, and calculating the thermal expansion of the piping between the pump outlet and the heat exchanger, the welding deformation of the stainless steel piping is successfully controlled. This reduces the stress between the equipment and the piping, accelerates the progress of piping installation and single-unit commissioning of the equipment, improves the service life of the equipment, and ensures the stability of the system operation in the later stages. Attached Figure Description

[0024] The accompanying drawings, which are provided to further illustrate the invention and form part of this application, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0025] Figure 1 This is a schematic diagram of the structure of the spring-supported pump, heat exchanger, argon charging protection device, etc. involved in the piping method of the present invention;

[0026] Figure 2 This is a partial welding schematic diagram of the present invention;

[0027] Figure 3 This is a schematic diagram of the alignment of the coupling of the present invention.

[0028] In the picture:

[0029] 1 is the pump body, 1-1 is the pump body flange, 1-2 is the pump body spring support leg, 1-3 is the spring support leg pad, 1-4 is the foundation anchor plate, 1-4 is the motor, and 1-5 is the coupling.

[0030] 2 is the pipe, 2-1 is the temporary blind flange gasket, 2-2 is the pipe flange, 2-3 is the bolt, 2-4 is the paper tape, 2-5 is the argon inlet, 2-6 is the protective argon pipe, 2-7 is the gas cylinder, 2-8 is the frame level, 2-9 is the demineralized water, 2-10 is the dial gauge, 2-11 is the upper pipe, and 2-12 is the concentric reducer.

[0031] 3 represents the heat exchanger, and 3-1 represents the heat exchanger flange. Detailed Implementation

[0032] To enable those skilled in the art to better understand the present invention, the present invention will be further described clearly and completely below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0033] like Figure 1 and Figure 2 As shown, in a typical embodiment of the present invention, the spring-supported pump includes a pump body 1, with an inlet and outlet on one side and a motor on the other side. The top of the spring-supported pump outlet is connected to a heat exchanger 3 via a pipe, the pipe 2 including an upper pipe 2-11 and a lower concentric reducer 2-12.

[0034] Pipeline 2 is installed directly above the outlet of the spring-supported pump. Four foundation anchor plates 1-4 are pre-embedded on the surface of the pump foundation for equipment installation. The pump body 1 is supported on four sets of pump body spring legs 1-2. The bottom of the pump body spring legs 1-2 has spring leg pads 1-3. The spring leg pads 1-3 are in direct contact with the foundation anchor plates 1-4. The horizontality of the foundation anchor plates 1-4 must be high, and the allowable deviation range must be controlled within 0.1mm.

[0035] The piping method for the spring-supported pump provided in this embodiment includes the following steps one through seven.

[0036] Step 1: Adjust the axis, center line, and level of the spring-supported pump body 1, and align the coupling 1-5 between the motor 1-4 and the spring-supported pump body 1.

[0037] Using the outlet of the spring-supported pump as a reference, a laser theodolite is used to adjust the outlet of the spring-supported pump to align with the centerline of the heat exchanger in both longitudinal and transverse directions. After adjustment, a frame level is used to precisely align the pump body of the spring-supported pump using the machined flange surface of the pump outlet as a reference. The longitudinal allowable deviation is ±0.05mm / m, and the transverse allowable deviation is ±0.1mm / m. A dial indicator is used to align the coupling between the motor and the pump body of the spring-supported pump, with an allowable deviation of ±0.03mm.

[0038] Step 2: Connect the pipe flange 2-2 of the upper pipe 2-11 to the heat exchanger flange 3-1.

[0039] More specifically, after the pump body axis, centerline, levelness, and coupling alignment have all passed inspection, a hand-operated hoist is first hung on both sides and the front side of the support steel structure of heat exchanger 3 to connect the upper pipe 2-11. Before installation, the flange sealing surface is carefully inspected for damage and defects, and PTFE plates are used to protect the sealing surface to ensure good sealing and prevent damage to the sealing surface during hoisting. The prefabricated section of the upper pipe 2-11 is installed in place using the oblique translation method, and the bolts 2-3 between heat exchanger 3 and pipe flange 2-2 are tightened.

[0040] Step 3: Align the center of the bolt hole of the pipe flange 2-2 of the concentric reducer 2-12 with the center of the bolt hole of the pump body flange 1-1 of the spring-supported pump, and install a temporary blind flange gasket 2-1 between the pipe flange 2-2 and the pump body flange 1-1. Then, insert bolts 2-3 into the corresponding bolt holes.

[0041] In this step, the inserted bolts 2-3 need to be tightened diagonally for four times as a centering guide. They cannot bear the weight of the upper pipe 2-11, and the inserted bolts 2-3 can be loosened freely.

[0042] Before inserting bolt 2-3, install temporary blind flange gasket 2-1. Temporary blind flange gasket 2-1 should be made of PTFE sheet with the same thickness as the permanent gasket.

[0043] Step 4: Inject water into the concentric reducer 2-12, introduce protective argon gas into the upper pipe 2-11, and seal the weld between the upper pipe 2-11 and the concentric reducer 2-12 with paper tape 2-4.

[0044] After 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 are installed, as follows: Figure 2 As shown, water is injected into the concentric reducer 2-12. Since the pipe is made of stainless steel, the water must be desalinated water with a chloride ion content ≤25ppm. The liquid level should be 30mm below the weld seam to achieve the effect of cooling during the welding process.

[0045] like Figure 1 As shown, the argon purging protection device for the root pass welding mainly includes a protective argon gas pipe 2-6 and a gas cylinder 2-7. The pressure gauge flange on the side of the upper pipe 2-11 serves as the argon purging inlet 2-5.

[0046] Connect the protective argon gas pipe 2-6 to the argon inlet 2-5, seal it with high-density sponge, and seal the weld seam with paper tape 2-4 to prevent argon gas leakage during welding, which could lead to welding defects caused by the failure of argon protection and create conditions for subsequent pipeline priming welding with argon.

[0047] Step 5: Weld the weld between the upper pipe 2-11 and the concentric reducer 2-12.

[0048] In argon arc welding, argon gas only serves as a protective gas and is highly sensitive to oil, rust, and other contaminants on the surface of the workpiece and filler metal. Improper cleaning can easily lead to defects such as porosity and inclusions in the weld. Thorough cleaning is essential before welding, completely removing grease, paint, coatings, lubricants, oxide films, and rust from the bevel surface and the inner and outer walls of the workpiece (15-20 mm each), ensuring a metallic luster. Strict cleaning procedures must be followed, and welding should commence as soon as possible after cleaning. Argon arc welding requires high argon gas purity, no less than 99.99%. High-purity argon gas ensures weld quality, improves welding efficiency, and reduces porosity.

[0049] Before welding, use stainless steel positioning plates of the same material to accurately position and fix the pipes on both sides of the weld seam to ensure that the pipes are in the correct position. After welding is completed, the stainless steel positioning plates should be cut and ground in a timely manner, and PT testing should be performed to ensure construction quality. Before this process, the fitter team should be notified to prepare personnel and tools to cooperate in the installation and ensure the smooth implementation of stress-free piping.

[0050] During welding, a frame-type level 2-8 with an accuracy of 0.03mm is placed on the precision-machined surface of the pump body motor bracket, and a dial indicator 2-10 is set up at the coupling to observe the changes in key parts of the pump body during the pipeline welding process. This allows for timely adjustments to the welding process based on the changes in the data from the frame-type level, ensuring that the initial data meets the specifications.

[0051] During welding, controlling welding parameters is crucial to preventing deformation. Two welders symmetrically use argon arc welding for the root pass, first tack welding to fix the weld joint, and then using welding wire and techniques similar to the final welding for the tack weld. The tack weld is 10-15mm long with a 2-3mm reinforcement, and four tack welds are used. The tack welds should ensure full penetration and be free of defects. The ends of the tack welds should be machined into a bevel shape to facilitate the joint. For the final root pass, appropriate welding current, voltage, and welding speed are selected. The welding current should be kept as low as possible, and the welding speed should be increased as much as possible to reduce welding heat input. The hand swing should be kept as small as possible; these measures can all reduce welding deformation. This ensures the quality of the weld joint while minimizing the thermal impact on the pipeline. Using a smaller welding current and a faster welding speed controls the welding deformation of the stainless steel pipeline.

[0052] To reduce welding deformation of the pipeline, argon arc welding is also used for the filler cover welding. During welding, the fitter observes the radial and axial displacement of the dial indicator on the coupling, and at the same time observes the changes of the frame level. Once a deviation is found, measures are taken immediately to stop welding on the side with the larger deviation and to restore the shape and size of the pipeline by welding in the opposite diagonal direction, so as to achieve the anti-deformation effect and keep the pump body within the allowable installation deviation range.

[0053] Step 6: 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.

[0054] After all welds are completed, the weld appearance quality is inspected; there are no pinholes or undercuts, and the weld reinforcement meets the specifications. After the welds have completely cooled, they are pickled and passivated, followed by non-destructive testing.

[0055] After passing inspection, slowly loosen bolts 2-3 between pipe flange 2-2 and pump body flange 1-1 to drain the internal demineralized water. Remove temporary blind flange gasket 2-1 and measure and accept the flange spacing, flange flatness, and longitudinal and transverse centerline. Flange spacing and non-parallelism are measured using a feeler gauge at four symmetrical points to check that the bolts inserted into the bolt holes can be freely inserted without jamming. The acceptance standard is a 4mm spacing between the two flanges. Since the pump speed is greater than 6000 r / min, the non-parallelism between the two flanges should not exceed 0.1mm; the concentricity deviation between the two flanges should not only allow the bolts to move freely within the bolt holes but also be less than or equal to 0.2mm.

[0056] Step 7: Replace the original gasket between the pipe flange 2-2 of the concentric reducer 2-12 and the pump body flange 1-1 of the spring-supported pump, and tighten bolts 2-3. Before adding the original gasket, check that the sealing surfaces of both flanges and the gasket are free from damage and defects.

[0057] The scope of protection claimed by this invention is not limited to the specific embodiments described above. For those skilled in the art, this invention can have various modifications and alterations. Any modifications, improvements, and equivalent substitutions made within the concept and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A piping method for a spring-supported pump, the spring-supported pump comprising a pump body, an inlet and outlet on one side of the pump body, and a heat exchanger connected to the top of the spring-supported pump outlet via a pipe, the pipe comprising an upper pipe and a lower concentric reducer, characterized in that... include: Step 1: Adjust the axis, centerline, and level of the spring-supported pump body, and align the coupling between the motor and the pump body. Step 2: Connect the pipe flange of the upper pipe to the heat exchanger flange; Step 3: Align the bolt hole center of the pipe flange of the concentric reducer with the bolt hole center of 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 bolt holes. Step 4: Inject water into the concentric reducer, introduce protective argon gas into 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 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 gasket between the concentric reducer flange and the spring-supported pump body flange and tighten the bolts.

2. The piping method for the spring-supported pump according to claim 1, characterized in that: In step one, using the outlet of the spring-supported pump as a reference, a laser theodolite is used to adjust the position of the spring-supported pump outlet and the center line of the heat exchanger in both longitudinal and transverse directions. After adjustment, a frame level is used to install and precisely align the pump body of the spring-supported pump using the precision-machined flange surface of the spring-supported pump outlet as a reference. A dial indicator is used to align the coupling between the motor and the pump body of the spring-supported pump.

3. The piping method for the spring-supported pump according to claim 2, characterized in that: In step one, when installing and precisely aligning the pump body, the allowable longitudinal deviation is ±0.05mm / m, and the allowable lateral deviation is ±0.1mm / m.

4. The piping method for a spring-supported pump according to claim 2 or 3, characterized in that: In step one, when the coupling is aligned with the shaft, the allowable deviation is ±0.03mm.

5. The piping method for the spring-supported pump according to claim 4, characterized in that: In step two, a hand-operated hoist is hung on both sides and the front side of the heat exchanger support to connect the upper pipe. The hand-operated hoist is used to connect the pipe flange of the upper pipe to the flange of the heat exchanger.

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

7. The piping method for the spring-supported pump according to claim 6, characterized in that: In step four, the water level inside the concentric reducer is raised to 30mm below the weld seam.

8. The piping method for a spring-supported pump according to claim 1 or 7, characterized in that: In step five, before welding, stainless steel positioning plates of the same material are used to position and fix the pipes on both sides of the weld.

9. The piping method for a spring-supported pump according to claim 8, characterized in that: In step five, during welding, a frame level is placed on the precision-machined surface of the motor bracket, and a dial indicator is set up at the coupling to observe the changes in key parts of the pump body during the pipeline welding process.

10. The piping method for a spring-supported pump according to claim 1 or 9, characterized in that: In step seven, before replacing the original gasket, 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 longitudinal and transverse center lines are measured and accepted.

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