Question Presently I have one PQR P1 G1 to P1 G2, so can I use this PQR for the below 1) P.no 1 G1 to P1 G1 2) P.no 1 G2 to P.no 1 G2 3) P.no 1 G1 to P.no 1 G2 The same time I can't catch the last sentence of the QW 403.5 The variable does not apply when impact testing of the heat affected zone is not required by other section. AnswerPlease find below the interpretation of QW 403.5.-Change in Material Grouping.-Supplementary essential variables. QW-403.5 (a) - When you are doing procedure qualification record (PQR) you have to use the same material type and grade which yo are plan to use in the production welding. QW-403.5(b) - Your actual base metal's P-Number and Group Number to be used in production welding shall match with the P Number and Group Number Listed in QW422 as mentioned in WPS. QW-403.5(c) - If you want to weld P Number-1Group Number-1 material to P Number-1Group Number- 1 and 2 material you should have two PQR as follows. 01. First PQR shall be P.No.1 Group No.1 with P.No.1 Group No.1 02. Additional PQR shall be P.No.1 Group No.1 with P.No.1 Group No.2 If you are having the two PQRs as mentioned above, you can weld same P.Number material with the same group number material as well as different group number. OR If you have the PQR of different P.number and Different Group Number,then you can weld the material with the same P.Number,Group number as well as the combination of Different P.Number and different Group number which you have qualified with the PQR. For example, If you have the PQR of P.No.1,Group No.2 with P.No.3,Group No.1..your Procedure shall be qualified for three types of combination as below. 01. P.No.1,Group No.2 with P.No.1,Group No.2 02. P.No.1,Group No.2 with P.No.3,Group No.2 03. P.No.3,Group No.1 with P.No.3,Group No.1.