UPMSP High School Plumbing - Code 976 key terms

Clothing and gear worn to reduce the risk of injury on site, such as safety helmet, goggles, gloves, safety shoes and ear protection. It is the last line of defence after engineering and work-practice controls.

Keeping the workshop and site clean and orderly: clearing offcuts, coiling hoses, storing tools and wiping up spills. Good housekeeping prevents slips, trips, fires, pest harbourage and lost tools.

A procedure for isolating energy before maintenance: switching off, locking the isolator, attaching a warning tag and verifying that isolation is effective. It prevents accidental start-up or release of stored pressure.

A structured examination of a task to identify hazards, decide who may be harmed and how, and record control measures before work begins. It is reviewed whenever conditions or methods change.

A short briefing held at the start of a shift covering the day's tasks, the hazards involved and the controls to be used. It confirms that workers have understood the safety instructions.

An adjustable wrench with hardened serrated jaws that grip round pipe for turning. Jaw grip increases as force is applied, but the teeth mark finished surfaces, so a strap wrench suits chrome work.

A hand tool with a hardened cutting wheel and rollers that scores and severs metal or plastic pipe squarely as it is rotated and gradually tightened. The internal burr is then removed with a reamer.

A tapered hand or spiral tool used to remove the internal burr left by a pipe cutter. Deburring restores the full bore, eases flow and prevents turbulence and erosion-corrosion at the joint.

The part of a stock-and-die set that holds hardened chasers and cuts an external taper thread on pipe as it is rotated and advanced. Correct chaser size and cutting oil give a clean thread.

A tool with sealed vials containing liquid and an air bubble; the bubble centres between graduation marks when the surface is truly horizontal or vertical. Used to check pipe falls and fixture alignment.

A pointed weight suspended on a cord to give a true vertical reference line. Plumbers use it to transfer points from ceiling to floor and to check that risers and stacks stand upright.

The standard approximate internal diameter used to designate pipe size, written in millimetres or inches, for example 15 mm (1/2 in). Actual outside diameter varies with material and wall thickness.

Steel pipe coated with zinc to resist corrosion, normally joined with screwed fittings and protected at cut ends with zinc-rich paint. Widely used for cold water lines and in older buildings.

Unplasticised polyvinyl chloride: a rigid, light, corrosion-resistant plastic pipe used for cold water, soil, waste and drainage. It is jointed with solvent cement or push-fit rings and is not suitable for hot water.

Chlorinated polyvinyl chloride pipe, with a higher chlorine content than uPVC, that tolerates hot water up to roughly 80 to 90 degrees Celsius. Used for hot water distribution and near water heaters.

High-density polyethylene pipe: tough, flexible and corrosion-resistant, supplied in coils and joined by butt fusion or electrofusion. Used for buried water mains, borewell lines and sewer force mains.

Seamless metal tube used for hot and cold water and for gas, joined by capillary soldering, brazing, press fittings or compression fittings. It is light, durable and tolerant of high temperature.

A fitting that changes the direction of a pipe run, commonly through 90 or 45 degrees. It is available in equal or reducing form with threaded, solvent-weld, compression or flanged ends.

A three-way fitting with one branch set at right angles to the main run, used to divide or combine flow. An equal tee has the same size throughout; a reducing tee steps the branch down.

A three-part screwed fitting with two end pieces and a central nut that lets a pipe run be disconnected without cutting or unscrewing the whole line. Useful at fixtures, valves and pumps.

Tape or paste applied to male threads to fill the spiral gap between mating threads and so prevent leakage. PTFE tape is wound clockwise, in the direction the fitting is screwed on.

A joint made by coating uPVC or CPVC pipe and socket with solvent cement, which softens the surfaces so that they fuse together. The pipe must be pushed fully home and briefly held.

A joint consisting of a body, a nut and a soft metal or plastic olive; tightening the nut compresses the olive onto the pipe to form a seal. Common on copper and small-bore plastic pipe.

A storage tank at roof level that supplies fixtures by gravity, giving steady low pressure and a buffer against supply cuts. It needs a float valve, an overflow pipe and safe cleaning access.

A valve operated by a floating arm or ball inside a tank: as the water rises the float closes the inlet and stops overflow. It is set to leave an air gap below the overflow level.

A pressure surge caused by the sudden stopping of flow, heard as banging in pipes and felt as stress on joints. It is reduced by slow-closing valves, air chambers or arrestors and secure clipping.

The depth of water held in a trap between the fixture and the drain, measured vertically, which blocks sewer gas from entering the building. It is typically 50 to 75 mm deep.

A trap whose body forms a U-shaped water seal, commonly fitted under sinks and basins and often provided with a cleaning eye. Its shape retains water while allowing waste to pass through.

A trapped fitting at ground level that receives waste from sinks, baths or yards, having a grating and a water seal, and discharging into the underground drainage line.

A pipe that carries sewage containing soil, that is human waste, from water closets. It is distinguished from a waste pipe, which carries sullage from sinks, baths, basins and floor traps.

A pipe open to the atmosphere above roof level that admits air behind the flowing discharge, protects trap seals and releases foul gases. It also equalises pressure within the stack.

The slope at which a drain is laid, expressed as a ratio such as 1:60 or as millimetres per metre, so that solids are carried along without the flow running so fast that water is left behind.

An access point built into an underground drain, fitted with a removable cover, allowing inspection, rodding and clearing of blockages. It is placed at changes of direction, gradient or pipe size.

A pictorial plumbing drawing in which pipe runs are drawn on 30-degree diagonals so that length, direction and fittings appear in one view. Often used for hot and cold water layouts.

A pressure test in which completed pipework is filled with water, pumped up to a specified test pressure and then examined over a set period for leaks and unacceptable pressure drop.

A drainage test in which smoke is forced into the system and the joints and connections are watched for escaping smoke, revealing leaks and confirming that trap seals are sound.

A priced schedule listing items of work with descriptions, units and measured quantities, prepared from drawings and specifications. It forms the basis for tendering, comparison of bids and payment.

The process of reading drawings and specifications to list every pipe, fitting, fixture and consumable required, with size and quantity, before pricing or ordering. Errors here distort the whole estimate.

The principles of honest, fair and responsible conduct at work: punctuality, respect for the customer's property, truthful quoting, safe working and refusal of bribes or shortcuts.

Spotting a plumbing-related opportunity and organising money, tools, staff and customers to run a profitable business, with attention to costing, licensing, record keeping and service quality.