1208.6.12.2, Heat-Fusion Joint, and Fittings is hereby deleted in its entirety and the following provisions shall be substituted therefor:

Heat-fusion joints shall be made in accordance with qualified procedures that have been established and proven by test to produce gastight joints at least as strong as the pipe or tubing being joined. Joints shall be made with the joining method recommended by the pipe manufacturer. Heat-fusion fittings shall be marked “ASTM D 2513.” All joints in approved heat fusion welded plastic gas piping shall be performed by individuals who are licensed as journeyman in the plumbing or mechanical trade and certified to do heat fusion welding by the manufacturer of the piping being installed.