Views: 0 Author: Kath Publish Time: 2024-08-02 Origin: Site
The following is mainly applicable to the condensate, cooling water, and air conditioning water pipeline systems in ordinary areas.
1) Use a wire brush and coarse sandpaper to polish the outer surface of the rusted pipe until the metal color is visible.
2) Immediately after rust removal, apply anti-rust paint to the outer surface of the pipe.
3) Anti-rust paint requirements: alkyd red lead anti-rust paint (or alkyd iron red anti-rust paint), alkyd thinner.
4) Before opening the paint bucket, roll the paint bucket on the ground to make the paint texture uniform in the bucket. Then, according to the environmental conditions such as temperature and the means (painting or spraying), pour the paint into a small container and mix it into a suitable concentration. Too thin or too thick paint will affect the effect of painting (spraying).
5) Leave 50-60mm long at both ends of the pipe without painting, and repaint after the welding process is completed.
6) During the storage process of pipe materials that have been painted with anti-rust paint, pay attention to padding to avoid rusting again. Use plastic cloth to seal the two sections of the pipe to prevent the inside of the pipe from being contaminated again.
1) Pipeline prefabrication should be carried out on a platform or a flat hardened prefabrication site. The prefabrication size should be carried out according to the revised pipe section drawing, and there should be room for adjustment to ensure transportation and lifting conditions. The markings should be made and the openings should be sealed in time to avoid pollution.
2) The prefabricated combined section should have sufficient rigidity and strength, otherwise temporary reinforcement measures should be taken, and the location of the lifting rigging binding point should be marked if necessary.
1) When the pipe diameter is less than DN25, a hand saw or a cutter can be used for cutting.
2) When the pipe diameter is ≤DN150, a grinding wheel cutter is used for cutting.
3) When the pipe diameter is ≥DN200, oxygen-acetylene flame cutting is used, but the iron oxide must be cleaned and the pipe end must be polished flat.
The grooves can be processed by groove machines, portable grinders, angle grinders, files, etc. For large diameter pipes, oxy-acetylene flame cutting can also be used for pre-processing. However, oxy-acetylene flame cutting must be polished to remove the oxide layer on the flame-cut surface and make the grooves neat.
1) When spot welding before welding, the root must be welded through. There must be no welding defects
2) The axis of the pipe group should be kept straight when welding.
3) The inner wall of the pipe group should be flush with the corresponding inner wall. If necessary, the misalignment should not exceed 10% of the wall thickness and should be greater than 2mm, and there should be no incomplete welding.
4) The performance of the welding equipment is intact, for example: the AC arc welding machine should have an appropriate no-load voltage and flexible welding current adjustment.
5) According to the wall thickness of the pipe, it is 2 or 3 times to survive.
6) Before each welding, the oxide layer on the surface of the previous welding should be brushed off with a wire brush.
7) The As wire should be close to the welding point and must be struck in the groove. Prevent arc damage to the weldment.
8) After the welding of the weld is completed, the welding slag and spatter should be removed.
9) The weld surface should not have: cracks, pores, slag inclusions, and incomplete welding.
1) The bending radius of the pipe bending should not be less than 1.5 times for hot bending; it should not be less than 1 times for stamping bending; the difference between the maximum outer diameter and the minimum bending radius of cold bending should not be greater than 8/100 of the outer diameter of the pipe, and the pipe wall thinning rate should not be greater than 15%.
2) The installation position and inlet and outlet directions of the valve should be correct and easy to operate; the connection should be firm and the opening and closing should be flexible; the arrangement of valves in a row should be neat and beautiful.
3) Before installing the electric valve, confirm the caliber and flange standards of the electric valve, and purchase the matching electric valve flange and reducer according to the accurate information.
4) The handles of all kinds of manual valves installed on the insulated pipes shall not be downward.
5) The filter of chilled water and cooling water should be installed on the pipe in front of the unit, with the correct direction and convenient for sewage discharge; it should be firmly and tightly connected to the pipe, and its installation position should be convenient for disassembly and cleaning of the filter. The material, specification and wrapping method of the filter screen should meet the design requirements.
6) Install exhaust valves at the highest point of the system and all high points where air may accumulate.
7) The slope of the condensate drainage pipe should comply with the requirements of the design documents.
1) Pipe supports that require insulation, such as chilled water, should be insulated from the pipes and use hardwood support brackets.
2) The spacing between pipe supports shall be based on the corresponding construction acceptance specifications or design requirements.
1) Perform pressure test in different zones and layers: Under the test pressure, stabilize the pressure for 10 minutes, and the pressure shall not drop. Then reduce the system pressure to the working pressure, and the pressure shall not drop within 60 minutes. The appearance inspection shows that there is no leakage and the system is qualified.
2)System pressure test: After all the zone pipelines are connected to the system trunk pipes, the system pressure test is performed on the pipelines of the entire system. The test pressure is based on the pressure at the lowest point, but the pressure at the lowest point shall not exceed the bearing pressure of the pipeline and components. After the pressure test is increased to the test pressure, stabilize the pressure for 10 minutes, and the pressure drop shall not be greater than 0.02MPa. After the system pressure is reduced to the working pressure, the appearance inspection shows that there is no leakage and the system is qualified.
Fill water from the top of the pipeline system and drain water from the bottom. When the color of the water at the outlet is the same as the color of the water inlet, it is qualified. Do not connect the equipment during flushing, and remove the filter screen of the filter.
1) The insulation material of the air conditioning water system uses rubber-plastic sponge insulation material.
2) The foamed rubber-plastic insulation material is bonded to the outer surface of the pipeline with special glue, and the joint is placed above the pipeline, and the joint is ensured to be tight and seamless.
