Pipe Bending and Forming

Pipe may be bent and components may be formed by any hot or cold method that is suitable for the material, the fluid service, and the severity of the bending or forming process. The finished surface should be flee of cracks and substantially free from buckling. Thickness after bending or forming should be not less than that required by the design. 

Bend flattening Flattening of a bend, the difference between maximum and minimum diameters at any eross section, should not exceed 8% of nominal outside diameter for internal pressure and 3% for external pressure. 

Bending temperature Cold bending of ferritic materials should be done at a temperature below the transformation range. Hot bending should be done at a temperature above the transformation range and in any case within a temperature range consistent with the material and the intended service. 

Corrugated and other bends Dimensions and configuration should conform to the design. 

P-Number Holding Holding time based on nominal thickness  

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