(a) Before beginning any welding, the welding surfaces must be clean and free of any material that may be detrimental to the weld, and the pipe or component must be aligned to provide the most favorable condition for depositing the root bead. This alignment must be preserved while the root bead is being deposited.

(b) See Appendix 14-C of this Title for acceptable preparation for butt welding pipe of unequal thicknesses.