ASTM B673, B677, B674 stainless steel pipe and tube covers following manufacturing types (Including hot finished or cold finished):
a. Seamless Pipe (SMLS): It covers stainless steel seamless pipe or tube in hot rolling or cold drawn.
b. Welded Pipe (WLD): Welded by an automatic welding process that does not add filler metal when welding.
c. Cold Worked Pipe (HCW pipe): The heavy cold-worked pipe that apply cold working of not less than 35% reduction in thickness of both wall, and welded to the welded pipe prior to final annealing. Do not use fillers during welding.
d. Welded and HCW pipe: Welded pipe and HCW pipe of 14 and smaller than NPS 14 shall have a single longitudinal weld. After approval by the purchaser, the welded pipe and HCW pipe with an NPS greater than NPS 14 shall have a single longitudinal weld or shall be manufactured by forming and welding two longitudinal sections of flat stock. So each welds are to be tested, inspected, inspected or treated.