Final answer:
The thickness to be used in applying the heat treatment provisions of ASME B31.3, Table 331.1.1 shall be determined based on the requirements stated in the ASME B31.3 code.
Step-by-step explanation:
When components of a piping system are joined by welding, the thickness to be used in applying the heat treatment provisions of ASME B31.3, Table 331.1.1 shall be determined based on the requirements stated in the ASME B31.3 code. The code specifies the minimum required thickness of the piping components that need to be heat treated after welding to ensure the structural integrity and to relieve the residual stresses.
It is important to refer to the ASME B31.3 code for the specific requirements regarding heat treatment and to consult with an engineer or a qualified professional to determine the appropriate thickness for applying the heat treatment provisions.