Determine piping system requirements and pipe sizing; Measure, cut, thread and bend pipes to required shape and size; Read blueprints, drawings and specifications to determine layout of plumbing system, water supply network and waste and drainage systems; Install, repair and maintain domestic, commercial or industrial plumbing fixtures and systems; Locate and mark positions for pipe connections, passage holes and fixtures in walls and floors; Cut opening in walls and floors to accommodate pipe and pipe fittings; Join pipes using couplings, clamps, screws, bolts, cement or soldering, brazing and welding equipment; Test pipes for leaks using air and water pressure gauges