Dear Engineers I am very curious to know about Piping material specifications (PMs) . How can I select the appropriate material for components which is used in piping? For example we use A106 Gr B for vapour pipes or A105 for flanges and A105/A234 for fittings less/bigger than 2". Now I want to know if the fluid changed to gas or oil or for example styrene monomer how I should choose these materials. what is the main refrence for choosing these materials? Are ASME or Bs or ASTM standards used for this? Thanks in advance!