Views: 0 Author: Site Editor Publish Time: 2022-06-17 Origin: Site
Curved pipe truss is applicable to large stadiums, public buildings and other kinds of structure buildings with circular and rectangular pipes as skeletons to form various shapes of spatial structures. The pipes, plates, welding materials and cast steel used in the fabrication of pipe trusses shall not only meet the requirements of corresponding design documents, but also with relevant regulations.
Curved pipe truss can be carried out in the factory or construction site according to the specific engineering conditions.
1. Shot (sand) derusting
Shot blasting is recommended for pipe truss members, and other methods are allowed, such as sand blasting, manual rust removal, acid pickling, etc., but the derusting grade required by the design must be met. The derusting grade must meet the requirements of gb8923 standard.
2. Take over
1) For pipe butt joint, the welding procedure qualification must be carried out according to standard, and the welding material, welding method and welding process parameters shall be determined to ensure the quality of the connecting pipe.
2) The butt weld of pipe usually adopts the equal strength full penetration welding with lining pipe (plate) and clapboard welding, and the equal strength fillet welding with outer sleeve and plug-in type. The quality grade of weld must meet the specific requirements of design drawings.
3) Different pipe butt joint forms can be divided into three situations: the same inner diameter, different wall thickness, the same outer diameter and different inner diameter and outer diameter.
4) Carbon dioxide gas welding and manual arc welding can be used for pipe welding. The welding seam of connecting pipe shall be cooled to the ambient temperature for visual inspection. The pipes made of Q195, Q235 and 20 shall be naturally cooled to the ambient temperature after welding; the pipes made of Q295, Q355, 09mnv, 09MnNb, 12mn, 12mn, 14MnNb, 16Mn, 16mnre and 18nb shall be welded for 24h; The pipes made of Q390, Q420, Q460, 15MnV, 15mnti, 16mnnb, 15MnVN and 14MnVTiRe shall be subject to ultrasonic flaw detection 48 hours after welding.