1) GB3087-82 of the low and medium pressure boiler seamless steel tubes provided. Variety of structural steel tubes for boiler specification, od 10~426mm, a total of 43. Wall thickness of 1.5~26mm amounted to 29. Locomotive boiler superheated steam pipes, drag pipes, small pipes and arched brick pipe outer diameter and wall thickness as otherwise provided.

(2) GB5310-95 of the high pressure boiler seamless hot-rolled tubes of diameter 22~530mm, 20~70mm wall thickness drawing (cold rolled) outer diameter 10~108mm, wall thickness range 2.0-13.0mm.

(3) GB3087-82 of the low and medium pressure boiler seamless steel and GB5310-95 the provisions of the seamless steel tubes for high pressure boilers. Appearance: steel internal and external surface cracks are not allowed, fold, roll fold, scarring, and hairline. These shortcomings should be completely removed. Clears the depth shall not exceed the nominal thickness tolerance, clean it up at the actual wall thickness wall thickness shall not be less than the minimum value allowed.