High Quality Content by WIKIPEDIA articles! Pipe fitting is the occupation of installing or repairing piping or tubing systems that convey liquid, gas, and occasionally solid materials. This work involves selecting and preparing pipe or tubing, joining it together by various means, and the location and repair of leaks. Pipe fitting work is done in many different trades: Plumbing, HVAC, manufacturing, fire prevention, and many others. Pipe fitters (sometimes called simply "fitters") are represented in the USA by the United Association of Journeymen and Apprentices of the Plumbing and Pipe Fitting Industry of the United States and Canada. Fitters work with a variety of pipe and tubing materials including several types of plastic, copper, steel, iron, aluminium, clay, and lead.