1. When designing and piping, the components, hydraulic components, pipe joints, and flanges that need to be connected should be considered comprehensively according to the hydraulic schematic diagram.

2. The arrangement and direction of pipeline laying should be neat and consistent, with distinct levels.Try to use horizontal or vertical pipe distribution, the non-parallelism of the horizontal pipe should be ≤2/1000; the non-verticality of the vertical pipe should be ≤2/400.Use a level meter to detect.

3. There should be a gap of more than 10mm between parallel or intersecting pipe systems.

4. The configuration of the pipeline must make it easy to load, unload and maintain pipelines, hydraulic valves and other components.Any section of pipe or component in the system should be freely disassembled and assembled as much as possible without affecting other components.

How to pipe the hydraulic pipeline?What are the 33 precautions for the layout of hydraulic pipelines?

5. When piping, the pipeline must have a certain rigidity and vibration resistance.Pipe brackets and pipe clamps should be appropriately configured.Curved pipes should be provided with brackets or pipe clamps near the bending point.The pipe shall not be directly welded with the bracket or pipe clamp.

6. The weight of the pipeline should not be borne by valves, pumps, and other hydraulic components and accessories; nor should the pipeline support the weight of heavier components.

7. For longer pipes, effective measures must be considered to prevent stress caused by temperature changes that cause the pipe to expand and shrink.

8. The pipe material used must have a clear original basis material, and pipes of unknown material are not allowed to be used.

9. If the diameter of the hydraulic system pipe is below 50mm, it can be cut by a grinding wheel cutting machine.Pipes with a diameter of more than 50mm should generally be cut by machining methods.If gas cutting is used, the part of the tissue that has changed due to gas cutting must be turned by mechanical processing method, and the welding bevel can be turned out at the same time.Except for the oil return pipe, the pressure from the pipe is not allowed to be cut with a roller-type extrusion cutter.The cutting surface of the pipe must be flat to remove burrs, oxide skin, slag, etc.The surface of the incision should be perpendicular to the axis of the tube.

10. When a pipeline is composed of multiple pipe sections and supporting parts, it should be taken over one by one in turn, and one section should be completed. After assembly, the next section should be configured to avoid cumulative errors after one welding.

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

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

13. The cold bending method can be used for pipes with an outer diameter of less than 30mm.When the outer diameter of the pipe is 30~50mm, cold bending or hot bending method can be used.When the outer diameter of the pipe is greater than 50mm, the hot bending method is generally used.

14. Welders who weld hydraulic pipelines should hold a valid high-pressure pipeline welding certificate.

15. Selection of welding process: Acetylene gas welding is mainly used for pipes with a wall thickness of less than or equal to 2mm for general carbon steel pipes.Arc welding is mainly used for pipes with a wall thickness of more than 2mm of carbon steel pipes.Argon arc welding is best used for pipe welding.For pipes with a wall thickness greater than 5mm, argon arc welding should be used for bottoming and arc welding for filling.When necessary, the method of filling the pipe hole with protective gas should be used for welding.

16. The electrode and flux should match the welded pipe, and the grade must have clear basis information, have a product certificate, and be within the effective use period.The electrode and flux should be dried in accordance with the product manual before use, and kept dry during use, and used on the same day.The electrode skin should be free of shedding and significant cracks.

17. Butt welding should be used for hydraulic pipeline welding.Before welding, the surface dirt, oil stains, moisture and rust spots of 10 to 20mm wide in and near the bevel should be removed.

18. Butt welding flanges should be used for the welding of pipes and flanges, and plug-in flanges should not be used.

19. Butt welding should be used for the welding of pipes and pipe joints, not in the form of plug-in.

20. Butt welding should be used for the welding of pipes and pipes, and plug-in welding is not allowed.

21. When butt welding is used for hydraulic pipelines, the inner wall of the weld must be 0.3to 0.5mm higher than that of the pipeline.Recessed into the inner wall is not allowed.After welding, use a file or a portable grinding wheel to flatten the higher welds in the inner wall.Remove welding slag and burrs to achieve a smooth finish.

22. The cross-section of the butt welding weld should be perpendicular to the centerline of the pipe.

23. The cross-section of the weld is not allowed to be at the corner, and it should also be avoided between the two bends of the pipe.

24. When welding the pipe, it must be positioned by spot welding according to the installation position, then removed for welding, and then assembled for shaping after welding.

25. During the whole welding process, the invasion of wind, rain and snow should be prevented.After the pipe is welded, the welds with a wall thickness of less than or equal to 5mm should be cooled naturally at room temperature, and should not be forced to cool by strong wind or water.

26. The welds should be thoroughly welded and the appearance should be uniform and flat.The welds of the pressure pipe should be sampled for flaw detection and inspection.27. After the pipeline and piping are welded, all pipelines should be pre-installed once according to their location.Connect the hydraulic components, valve blocks, valve frames, and pumping stations.Each interface should be naturally affixed and aligned, and cannot be connected by strong torsion.When loosening the pipe joint or flange screw, there must be no large dislocation, off-seam or angle of rotation relative to the centerline of the binding surface.If this happens, it can be eliminated by roasting on fire.

28. The pipe clamp and the rack can be welded firmly after all the piping is completed, or it can be handed over as required.

29. After the pipeline is piped, welded, and pre-installed, it will be disassembled again for pickling and phosphating treatment.After pickling and phosphating the pipeline, hot air is introduced into the pipeline for rapid drying.After drying, if the system is reinstalled in a few days and the hydraulic oil is introduced into the pipe, it will generally not be rust-proof, but it should be kept properly.If it needs to be shelved for a long time and anti-rust coating is required, it must be coated after 48 hours of phosphating treatment.It should be noted that the anti-rust coating must be compatible with the cleaning fluid or hydraulic oil used in future pipeline cleaning.

30. Before the pipeline is installed again after pickling, phosphating, and drying, the inner wall of each pipeline needs to be pre-cleaned once.After the pre-cleaning is completed, it should be reinstalled into the system as soon as possible, and the overall cycle purification treatment of the system should be carried out until it reaches the cleanliness level required by the system design.

31. The application of hoses is limited to the following occasions：

(1) Between the movable elements of the equipment；

(2) To facilitate the replacement of replacement parts；

(3) Suppress the transmission of mechanical vibration or noise.

32. The installation of the hose must be careful not to cause additional force, distortion, sharp bending, friction and other undesirable working conditions on the hose and joints.

33. Before the hose is loaded into the system, the inner cavity and joints should also be cleaned.