5　Welding Work

5.1　General Requirements

5.1.1　This chapter is applicable to the quality acceptance of welding work for steel tower and mast structure during manufacture and installation.

5.1.2　The welding work of steel tower and mast structure may be divided to one or several inspection lots according to the corresponding division principles of inspection lots for the manufacture and installation work of steel tower and mast structure.

5.1.3　For carbon construction steel，the flaw detection of welding seam shall be carried out after the welding seam has cooled to the ambient temperature；and for low-alloy construction steel，the flaw detection of welding seam shall be carried out 24hrs later than the completion of welding.

5.1.4　After the completion of welding seam，the name of welder performing the welding seam shall be stamped on the welding seam and area specified in welding procedure by the steel seal of the welder.

5.1.5　The quality of welding seam on steel pole shall be in conformity with the design requirements.Girth butt-jointed welding seam of pipes shall take the form of full penetration welding joint and not be less than gradeⅡ.The quality of longitudinal butt-jointed welding seam should not be less than gradeⅡand the quantity of longitudinal welding seam shall not be more than two.

5.1.6　Where butt-jointed welding is conducted for main structure，the number of butt welding joints should not exceed one within one rod section or one tower layer.