Hydraulic steel pipe installation is the main project of hydraulic equipment installation. The quality of pipeline installation is one of the keys to the normal operation of hydraulic system.

1. When designing and piping, the components, hydraulic components, pipe fittings and flanges to be connected should be considered first according to the hydraulic schematic diagram.

2, the arrangement and direction of pipeline laying should be neat and consistent, distinct. Try to lay pipelines horizontally or vertically, and the non-parallelism of horizontal pipelines shall be ≤ 2/1000; The verticality of vertical pipes shall be ≤2/400. Check with a level.

3. The gap between parallel or cross piping systems shall be greater than10mm.

4, pipeline configuration must make the pipeline, hydraulic valve and other components easy to load and unload and maintain. Any pipe or component in the system should be disassembled as freely as possible without affecting other components.

5. When the hydraulic steel pipe is lengthened, the pipe must have certain rigidity and vibration resistance. Pipe supports and pipe clamps shall be properly configured. Bends should be equipped with brackets or pipe clamps near the starting point. Pipes shall not be welded directly with brackets or pipe clamps.

6. The weight of pipelines shall not be borne by hydraulic components and accessories such as valves and pumps; Piping should not support heavy component weight.

7. For long pipelines, effective measures must be considered to prevent the stress caused by the expansion and contraction of pipelines due to temperature changes.

8. The pipeline materials used must have clear original basic materials, and pipelines with unknown materials are not allowed.

9, hydraulic system diameter below 50mm available grinding wheel cutting machine cutting. Generally, pipes with a diameter greater than 50mm should be cut by machining. If gas cutting is used, the structural changes caused by gas cutting must be removed by mechanical processing, and the welding groove can be turned. Except for the oil return pipe, the pressure is not allowed to be cut by a roller cutter. The cutting surface of the pipe must be smooth without burr, scale, slag, etc. Will be removed. The cutting surface shall be perpendicular to the pipeline axis.

10. When the pipeline consists of multi-section pipe sections and pipe fittings, they should be connected section by section in turn to complete a section. After assembly, the next section should be configured to avoid the accumulated error caused by one-time welding.

1 1. In order to reduce local pressure loss, all sections of the pipeline should avoid local sharp expansion or contraction and sharp bending.

12. The pipeline connected with the pipe joint or flange must be straight, that is, the axis of the pipeline should be parallel to and coincident with the axis of the pipe joint and flange. The length of the straight line segment should be greater than or equal to 2 times of the pipe diameter.

13, pipes with outer diameter less than 30mm can be cold-bent. Cold bending or hot bending can be used when the outer diameter of the pipe is 30 ~ 50 mm, and when the outer diameter of the pipe is greater than 50 mm, the hot bending method is generally used.

14. Welders welding hydraulic pipelines shall hold valid welding certificates for high-pressure pipelines.

15. Selection of welding process: acetylene gas welding is mainly used for ordinary carbon steel pipelines with wall thickness less than or equal to 2mm. Arc welding is mainly used for carbon steel pipes with wall thickness greater than 2mm. Argon arc welding is the best way to weld pipes. For pipes with wall thickness greater than 5mm, argon arc welding shall be used as backing and arc welding shall be used for filling. If necessary, the pipe hole should be filled with protective gas for welding.

16, covered electrode, flux should match the welded pipe, and its brand must have clear evidence, product certificate and be within the effective use period. Covered electrode and flux should be dried according to the product instructions before use, and kept dry during use, and used on the same day. Covered electrode coating should be free of shedding and obvious cracks.

17 and changben hydraulic steel pipes should be butt welded. Before welding, the groove with the width of 10 ~ 20 mm and the surface dirt, oil stain, moisture and rust spots near it shall be removed.

18. welded flange shall be used for welding pipes and flanges, and plug-in flanges shall not be used.

19. Butt welding shall be adopted for the welding of pipes and pipe joints, and plug-in type shall not be adopted.

20. Butt welding shall be adopted for pipeline welding, and plug-in welding shall not be adopted.

2 1. When butt welding is used for hydraulic pipelines, the inner wall of the weld must be 0.3 ~ 0.5mm higher than the pipeline. The inner wall is not allowed to sag. After welding, use a file or hand-held grinding wheel to smooth the weld with high inner wall. Remove welding slag and burr to achieve smoothness.

22, butt weld section should be perpendicular to the center line of the pipeline.

23, weld section is not allowed in the corner, also should avoid between the two bends of the pipeline.

24, welding pipe, must first according to the installation position of spot welding positioning, and then removed for welding, welding and then put on plastic sheets.

25, in the whole process of welding, should prevent the invasion of wind, rain and snow. After the pipeline is welded, the weld with a wall thickness of 5mm or less shall be naturally cooled at room temperature, and strong wind or water spray shall not be used for forced cooling.

26, weld should be penetration, appearance should be uniform and flat. Pressure pipeline welds shall be inspected by sampling flaw detection.

27. After the pipes are welded, all pipes shall be pre-installed once according to their positions. Connect hydraulic components, valve group, valve frame and pump station. All interfaces should fit naturally and be centered, and cannot be twisted forcibly. When loosening the pipe joint or flange screw, there must be no big dislocation, dislocation or angular swing relative to the center line of the joint surface. If this happens, it can be eliminated by baking and setting. (Guangzhou Changben)

28. Pipe clamps can be welded to the rack after all piping is completed, and can also be delivered as required.

29. After pipeline installation, welding and pre-installation, the pipeline shall be disassembled again for pickling and phosphating. After pickling and phosphating, hot air is introduced into the pipeline for rapid drying. After drying, if the system is reassembled in a few days, long hydraulic steel pipe oil will be introduced into the pipeline, which is generally not rust-proof, but it should be properly kept. If it needs to be put on hold for a long time, it needs to be coated with antirust paint, and it must be phosphatized for 48 hours before coating. It should be noted that the antirust paint must be compatible with the cleaning fluid or hydraulic oil used for pipeline cleaning in the future.

30. Before installing pipes again after pickling, phosphating and drying, the inner wall of each pipe should be cleaned in advance. After pre-cleaning, the system should be reassembled as soon as possible, and the system should be fully purified until it reaches the cleanliness level required by the system design.

3 1, the application of hose is limited to the following occasions:

Between the movable elements of the device

-Replacement location for easy replacement of parts

-Places where mechanical vibration or noise is suppressed.

32, the installation of the hose must be careful not to make the hose and joint cause additional stress, distortion, sharp bending, friction and other bad working conditions.

33, hose into the system, the inner cavity and joint should also be clean.