This checkoff list could be used by a scribe to keep track of which Scouts have earned which merit badges or could be used by an individual Scout.
Plumbing Merit Badge
Plumbing, including pipe fitting, is an important and well-paid occupation. The industry is quite broad. It covers installations and repairs in homes, commercial properties, and factories. Plumbing pipelines are used for water supply, waste drainage, natural-gas heating, and many other purposes.
Printable helps for requirements:
A reader asks about how old a Scout should be to work on a merit badge. The Guide to Advancement provides some answers.