Plumbing Tools, Materials and Fittings
This domain checks whether you can identify pipes, fittings, valves and tools, select them for the service conditions, and use them without damaging the joint or the material. Questions often compare material properties, pressure-temperature ratings and correct tool choice.
Materials and their limits
Common materials are galvanized iron (GI), copper, chlorinated polyvinyl chloride (CPVC), polypropylene random copolymer (PPR), unplasticized PVC (PVC-U), soil-waste-rainwater (SWR) pipe, cast iron and high-density polyethylene (HDPE). GI is strong but corrodes; copper resists corrosion and handles heat; CPVC and PPR handle hot water, while PVC-U is for cold water and drainage. Always check the pressure-temperature derating: a pipe rated at a high pressure when cold may be rated much lower at 70 °C.
Fittings, valves and tools
Know elbows, tees, reducers, couplings, unions, caps, nipples, bushings and crosses, plus gate, globe, ball, butterfly, check and pressure-reducing valves. Gate and ball valves isolate; globe valves throttle; check valves allow one-way flow. Tools include pipe wrenches, chain wrenches, hacksaws, pipe cutters, reamers, deburring tools, threading dies, flaring tools, press and crimp tools, levels and pressure gauges. Use a backing wrench on valves and fittings so the pipe thread does not carry the tightening force.
Worked example
A copper hot-water line must connect to an existing GI pipe. Direct copper-to-GI contact creates galvanic corrosion, so fit a dielectric union or insulating flange at the transition. For 70 °C water at 4 bar, PVC-U is unsuitable; select CPVC or PPR after checking the manufacturer's pressure-temperature chart.
Traps that cost marks
Do not use a pipe wrench on chrome-plated or plastic fittings; do not overtighten tapered threads and split the fitting; do not use a gate valve for fine throttling; observe the arrow on a check valve; and do not mix BSP and metric threads.