Is The Compressed Air Piping Installation Up To Standard?

The appearance quality of butt weld of compressed air pipe should be free of cracks, pores, slag, melting spatter and unwelded penetration. The depth of biting edge should be less than 0.5mm, the total length on both sides of the weld should be less than 10% of the total length of the weld, and the height of the weld should be less than or equal to 1+0.1b (b is the width of the weld), and not more than 3mm. For pipe fabrication, the pipeline cutout and pipe groove should be processed. The end face of the cut shall be flat and perpendicular to the axis of the pipe. The allowable deviation is 1% of the pipe diameter and not more than 2.0mm. The form and size of the pipe welding bevel shall be in accordance with the provisions of the welding operation instructions. After beveling, iron filings, burrs, etc. should be cleaned up.

Pipe bending should meet the following requirements: Bending should be cold bending, bending very small bending radius should not be less than 3 times the outside diameter of the pipe; the use of stamping elbow, the bending radius shall not be less than double the outside diameter of the pipe. After bending, the very large outside diameter and very small outside diameter difference shall not exceed 8% of the pipe diameter. The bending part of the pipe shall not have folds, flaking, and other defects. Pipe thread processing should be consistent with the provisions of the design and technical documents. After thread processing, the surface shall be free of cracks, dents, burrs, and other defects. For slight mechanical damage or incomplete cross-section of the thread, the total length shall not exceed 1/3 turn, and the reduction of thread height shall not exceed 1/5 of its height.

The laying of compressed air pipe should meet the following requirements: The direction of the pipeline should be in accordance with the requirements of the design technical documents, the permissible deviation of the straightness of the horizontal pipeline is 2/1000 and not more than 30mm; the permissible deviation of the verticality of the vertical pipe is 3/1000 and not more than 20mm; the pipeline should be installed in accordance with the coordinate position and elevation dimensions as stipulated in the design technical documents. The allowable deviation of the coordinate position is 15mm, and the allowable deviation of the elevation is ±15mm. The distance between the outer wall of the pipe and the edge of the neighboring pipes and pipe fittings should not be less than 10mm, and the flanges or live joints on the same row of pipes should be staggered by not less than 100mm. The pipe through the wall should be equipped with casing, and the distance between the joint position and the wall should be more than 800mm. The slope of the compressed air pipe should be in accordance with the provisions of the technical documents. If there is no provision, the slope is 12.5/1000～25/1000. The flange connection should be concentric with the pipe, the connecting bolts should be free to penetrate, the mating surfaces of the two flanges should be parallel, and the permissible deviation of parallelism should not be greater than 1.5/1000 of the diameter of the flange.

The installation of pipe supports and pipe clamps shall comply with the following requirements: The bracket installation position is correct, firmly fixed. Pipes should be in close contact with pipe clamps. Pipe brackets and pipe clamps shall not have pipe welds. The pipe bracket and straight pipe spacing between the requirements should be met, the curved part should be added near the beginning of the bracket. Pipe supports shall not be in direct contact with each other. The installation of the hose shall comply with the following requirements: For hoses with an outside diameter greater than 30mm, the very small bending radius shall not be less than 7 times the outside diameter of the hose. The hose shall not be twisted or deformed. There shall be no friction between hoses or between hoses and other objects. When the hose is close to the heat source, thermal insulation measures must be taken. The thickness and number of times the pipe is coated with paint should be in accordance with the technical requirements of the design. The coating shall be uniform in color and free from defects such as leakage, flow, and bubbles. The compressed air pipe used for pipeline blowing must be tapped and blown according to the process. After blowing, the inner wall of the pipe shall meet the provisions of the design technical documents. If not specified, there shall be no rust, oxidized skin, and other foreign matter.