(i) These regulations cover both hot finished and cold drawn seamless pipes of ferritic alloy steel grades.  These shall conform in all respects with the requirements herein specified.

(ii)  The seamless pipes conforming to other national/international standards which are known to be commonly used as being suitable for high temperature service can also be used with the designations of the national/international standards, provided such materials are not specifically prohibited by the regulations.

(iii)  While making pipes to other national/international standards the allowable stresses of the respective standard shall be strictly followed while designing the tubes.

(iv)   The design metal temperatures shall not exceed the following limits

Grade                                                              Temp. Degree C (Degree F)

P1, P2                                                                          537 (1000)

P5, P9, P11, P12, P22, P91, X20CrMoV121                    648 (1200)