Seamless Pipe and ASME Standards

It has been a while since I have been involved with this, but if memory serves you can use seamless pipe. However, there are some tolerance corrections that apply to seamless pipe versus rolled plate (0.85 rings a bell, but you will need to check). The idea behind this is that plate (or skelp formed into ERW pipe) is more closely controlled to thickness than is seamless pipe.

I apologize for this partially speculative explanation. Unfortunately, most construction codes do not explain their rationales; they just lay out the specs, and not even God seems to know why. There probably is a valid reason, but it is often damned tough to find out what the reason is.

When calculating the required thickness, the nominal thickness of the pipe must be multiplied by 0.85 or 85% because when seamless pipe is made it is drawn through dies and over mandrells to produce pipe. As the mandrell is not perfectly centred all the time the Standard permits a 12.5% deviation from perfect centre which means the wall thickness can be 0.85 as a minimum. The wall thickness will be thicker at the opposite side of the pipe but the thinner part must be used to calcuate the hoop stress.

We use .875 multiple, not .85.

Yes, you can use pipe per B16.19, the B16.19 specification will be invoked by the Material Specification you select such as A106 Grade B.

B36.19 is a standard for stainless steel pipes. can we combine it with a material specification for carbon steel pipes ?

I mean that, if dimension and wall thickness are complied with one of the specification (B36.10 or B36.19), material can be used for ASME VIII div. 1 pressure vessels.

What is your opinion ?