8　Welding

8.1　Welding Procedure Qualification（WPQ）

8.1.1　The construction company shall determine if there is any data on welding procedure qualification（WPQ）prior to welding.The qualification must be made if such data are not available，or if the applicable scope is not suitable for the welding work.

8.1.2　The WPQ is required for the initial welding of steel.

8.1.3　The WPQ shall be in accordance with DL/T 868，and shall comply with the following requirements：

1　Specimens used for WPQ purposes shall be of butt weld type or T-fillet weld type.Specimens for butt joints shall include vertically and horizontally welded positions for wall plates of the bottom ring.Specimens for T-fillet joints shall be cut from the specimens for fillet joints connecting bottom-ring wall plates and bottom margin plates.The preparation and examination of specimens for T-fillet joints shall be as specified in Appendix A.

2　All specimens with butt-weld joints are subject to stretching and horizontal bending test.An impulse test is also required where the ballistic work on the base metal is required in design.