The joint bevels shall be prepared in accordance with the registered and approved weld procedure. Internal and external surfaces to be welded shall be clean and free from paint, oil, rust and scale.
Stamp the welder's identification symbol adjacent to all pressure welds with low stress stamp in carbon and low alloy steels with wall thickness of 6.4 mm (1/4") or greater. For flanged joints where the pipe wall thickness is less than 6.4 mm (1/4"), stamp the welders identification on the edge of the flange. When both members of a weld are less than 6.4 mm (1/4") thick, the welder's identity shall be recorded in a permanent written record.
For austenitic stainless steels, high alloy steels and non-ferrous metals, the welder's symbol shall be applied with waterproof paint.
The permanent marking material used on austenitic stainless steels and non-ferrous alloys shall not contain any harmful metal, metal salts, or elements such as zinc, lead, chlorides, sulphur, and other low melting point metals. Submit type of paint or ink including analysis of the above elements for OWNER's approval.