Official Joint Plumbing Apprentice and Journeyman Training Manual: "Section J Natural Gas Systems" (Revised 1983 edition). Produced by craftsmen affiliated with the American Federation of Labor - Congress of Industrial Organizations (AFL-CIO). Essential vintage union trade technical reference covering fuel gas piping, system installations, pressure regulations, and safety standards. Great resource for plumbers, pipefitters, trade union members, and industrial historians. Pages are pristine, clean, and unread with no interior markings. Strong binding and solid cover.
