Regarding essential variables, I have an issue. The contractor has a PQR where were made longitudinal welds (butt wedling) in a Split T fitting around a pipe. These longitudinal welds are to clamp two halves of the fitting together and they are not in direct contact with the pipe, because there is a backing strip. The base material of the fitting and of the pipe is X52 which has a yield strength of 359 MPa. In the project, the fitting material is a Gr 70 (260 MPa) and the pipe material is a Gr B (241 MPa). According to API 1104, I can not aprove the work, because the base material (of the pipe and of the fitting) is less than the one of the group which would qualify it (290 MPa - 448 MPa), right?