16. Steel Welding
All welding must be done in accordance with applicable welding standards, JGJ/T81 and National Standard GB/T1595-2010 Constructional Steel Structure Welding Standard, with qualified personnel and approved welding process.
Welders must be qualified by testing and hold valid welding certificates. Where necessary, the contracting authority shall inspect welders’ qualification at any time, and all welders’ certificates must be present on site.
The welding process and quality of welding should be in accordance with requirements of related standards.
All welders must folllow proper health and safety guidelines when welding .
The “Welding procedure qualifying test” must be conducted in accordance with JGJ81-2002 Construction Steel Structure Welding Technical Regulation and JGJ76-2003 Building Steel Structures Qualifying Welding Technology verifications.
The size, construction, the level of the equipment of the welding equipment used shall meet the requirements for the welding process qualified in the welding procedure qualification tests and in accordance with the GB/T1595-2010 Constructional Steel Structure Welding Standard.
The welding shall be done in accordance with the welding procedure. All welding must be done under the constant supervision of a qualified engineer.
The welding slag should be removed at regular intervals.
Welders must check the welding quality after completing the welding. Any weld that does not meet the required quality standards must be reworked or entirely removed and replaced. Defects that have been encountered in welding shall not be overlooked. The contact surfaces of the joints shall be in strict accordance with related specifications for straight seams, corners, etc.
The roots of the welds must be pre-treated before the next layer is applied.
Third party inspections must be performed on all the welding. Reports of inspections must be kept.
The welding slag, welding splashes and welding powder should be removed promptly.
The complete welded structure must be inspected in detail after welding under the direction of the qualified engineer.
The welding consumables such as flux, welding rod and other welding materials must be of specified quality and conform to relevant standards. Their properties must also be suitable for the type of welding to be carried out.
The manufacturer of steel structures shall provide proof that welding work is compliant with related standards.
All welds must be free of undercut, large pores, lack of inclusions, cracks, concave or convex defects, false appearance and cold cracks.
No welding defects should remain when work is considered finished.
Upon completion of welding, the welding joint parts must be cleaned and finished with grinding tools.
Destructive tests for weld metals must be conducted in accordance with related standards.
Welding requirements for connecting parts must be in accordance with the technical regulations of related specifications.
The manufacturer shall mark the welding position, welding method and other relevant information on all welding parts, and keep related records for welding.
Both individual engineers and supervision inspectors must inspect all welding before assembly, and only after successful inspection, the welded pieces may be used in the construction works.
When all welding work is finished, qualified personnel must check strictly, issue reports and issue certificate of the welding quality.
