Heat treatment is used to avoid or alleviate the detrimental effects of high temperatures, which are unavoidable during the welding process. The heat treatment required and the recommended temperatures and holding times vary among metals. They are specified in ASME B31.3, Table 331.1.1, Requirements
Steel pipesSteel pipes to BS 1387 are normally specified in the nominal bore sizes given in Table 1. Finishes can be black or galvanised, the latter being preferred for corrosion resistance.