Hi

I have a question regarding pipe stress analysis of buried pipes.

I don't know which piping standard do I have to use in order to calculate stresses in light slope piping system in refinery, which is in most of it's part buried underground. Piping material is SA 106 Gr. B and pipe is coated with polyethylene (PE) for corrosion and mechanical protection. Pipe is operating at 260°C.

Can I use B31.3 or some other ASME piping standard, for example B31.8...