Haryana BSEH Secondary NSQF Plumbing key terms

The depth of water held in a trap that blocks sewer gas from entering a building. It is measured between the trap's crown weir and its dip tube, and normally ranges from 25 mm to 75 mm.

The lower edge of the outlet side of a trap, over which water flows out once the trap is full. It marks the top level of the standing water seal.

A U-shaped fitting under a fixture that holds a water seal and drains into the waste pipe. Its shape lets waste flow out while trapping a plug of water against sewer gases.

A trap shaped like the letter S that drops straight down after the seal. It tends to siphon itself empty, so modern codes usually forbid it in favour of a P-trap with a vent.

A pipe that admits air into the drainage system and lets foul gases escape above roof level. It protects trap seals from siphonage and keeps the flow in drains smooth.

The vertical or horizontal pipe that carries sewage, meaning waste from water closets, to the drain. It is kept separate from pipes that carry only sullage where a two-pipe system is used.

A pipe that carries sullage, that is, waste water from sinks, basins, baths and similar fixtures, but not from water closets. It connects fixture traps to the drainage stack or drain.

Liquid waste from washing and household use that contains no human excreta, such as water from sinks, baths and kitchen washing. It is carried by waste pipes, not soil pipes.

The main vertical pipe in a building's drainage system that receives waste from branch pipes on each floor and carries it down to the building drain. It usually continues upward as a vent.

A small covered chamber built on a drain at a junction or bend so that the line can be rodded and inspected. It is shallower than a manhole and usually has a removable cover at ground level.

A covered opening large enough for a person to enter, giving access to a sewer or drain for cleaning, inspection and repair. It is built at changes of direction, junctions and intervals along the line.

A trap fitted at the outlet of a floor or yard drain that holds a water seal and catches solid matter before it enters the drainage line. It is reached through a grating at surface level.

The pipe that carries waste from a group of fixtures or a single stack to the main drain or sewer line. It connects to the main line at a junction, often through an inspection chamber.

The slope at which a drain is laid so that waste flows by gravity. It is stated as a ratio such as 1 in 60, meaning the pipe drops one unit of height for every 60 units of length.

The minimum flow speed in a drain that keeps solids moving and stops silt from settling. For small sewers it is commonly taken as about 0.6 to 0.9 metres per second.

A steel pipe coated with a layer of zinc by galvanising to resist rust. It is joined by threaded fittings and is common in older Indian water supply and plumbing work.

A pipe cast from grey cast iron, strong in compression and used for soil, waste and rainwater lines. It is heavy and brittle and is joined with sockets, lead or rubber gaskets.

A light, corrosion-resistant plastic pipe made from polyvinyl chloride, used for cold water supply and drainage. It is joined with solvent cement or rubber ring push-fit joints.

A chlorinated polyvinyl chloride pipe that withstands higher temperatures than ordinary PVC, so it can carry hot water. It is joined with solvent cement made for CPVC.

A joint made by coating the pipe end and fitting socket with solvent cement, then pushing them together. The cement softens the plastic so the surfaces fuse into one piece.

A joint where the pipe end is pushed into a fitting containing a rubber ring or seal that grips and seals it. It needs no cement or heat and allows some movement.

Cutting a screw thread on the end of a pipe so it can be screwed into a fitting. For GI pipe it is done with a pipe die or threading machine, and the cut thread is protected with paint.

An adjustable hand tool with serrated jaws that grip round pipe for turning or holding. The jaw teeth bite harder as force is applied, so it grips in one direction only.

A clamping device that holds a pipe firmly while it is cut, threaded or filed. Its jaws are shaped to grip round sections without crushing them.

A hand tool with a sharp cutting wheel and adjustable rollers that is rotated around a pipe to score and cut it. The wheel is tightened a little each turn to avoid burring the pipe.

A tool used to remove the burr or sharp inner ridge left on a pipe after cutting. A clean bore lets water flow freely and stops debris collecting at the joint.

The operation of removing the rough metal or plastic edge left inside and outside a cut pipe. It protects hands, allows fittings to seat fully and reduces turbulence and scale build-up.

A cord with a pointed weight hung from a fixed point to show a true vertical. Plumbers use it to check that a riser or stack is upright and to mark positions on walls.

A tool with a sealed glass tube containing liquid and an air bubble, used to check whether a surface is horizontal or vertical. The bubble centres between the marks when the surface is true.

A valve fitted on a supply pipe that can be turned by hand to start or shut off the flow. It is used to isolate a fixture, a branch or the whole building for repair.

A valve in which a flat disc is raised or lowered by a screw to open or close the pipe. It is used for isolating flow and should be left fully open or fully closed.

A valve controlled by a floating ball or lever that closes the inlet when a tank is full and opens it as the level drops. It keeps storage tanks filled automatically.

A storage tank placed on the roof or at high level that supplies water to fixtures below by gravity. Its height above the highest fixture sets the pressure available.

The height of water column above a point, which produces the pressure at that point. About 10 metres of water head gives roughly one bar of pressure.

A device fitted on the incoming supply that measures the volume of water used. A consumer meter records consumption for billing and helps detect leaks when no water is being drawn.

A fixture used for the reception and flushing away of human excreta. The Indian or squatting type is set into the floor, while the European type is a seated pan.

A cistern that stores water and releases a measured flush into a water closet or urinal. A low-level tank is mounted near the pan and connected by a flush pipe.

A bowl-shaped fixture supplied with hot and cold water and fitted with a waste outlet, used for washing hands and face. Its outlet connects to a trap and then a waste pipe.

A pocket of trapped air in a pipe or fitting that blocks or reduces the flow of water. It is cleared by opening a vent or by flushing water through under pressure.

A loud knocking in pipes caused by a sudden change in flow, such as a tap closing quickly, which sends a pressure surge through the line. It is reduced by air chambers or arrestors.

The process of finding where water escapes from a pipe, joint or fixture. Methods include checking the meter with all taps closed, tracing damp patches and testing joints under pressure.

A check in which a completed pipe section is filled with water or air and held at a set pressure to prove it has no leaks. It is done before pipes are buried or concealed.

The clothing and gear worn to protect a worker from injury, such as safety helmet, goggles, gloves, safety shoes and ear protection. It is the last line of defence against hazards on site.

A safety procedure that isolates a machine or power supply and fixes a lock and warning tag to it before work begins. It stops equipment being switched on while someone is repairing it.

Keeping a workplace clean and orderly by clearing waste, storing tools and materials safely and removing spill hazards. Good housekeeping is the simplest way to prevent slips, trips and fires.

An enclosed area such as a manhole or septic tank with limited entry and poor ventilation, where dangerous gases can collect. Entry requires testing the air, a standby person and rescue arrangements.

The activity of spotting a need, organising money, materials and people, and taking on the risk of running a business to meet it. A plumbing entrepreneur may work as a contractor or open a supply shop.

A written offer stating the price and terms at which a trader or contractor will supply goods or carry out work. It lets the customer compare offers before placing an order.

A document sent by a supplier to a buyer listing goods or services supplied, quantities, rates and the total amount due. It serves as a record for payment and for accounts.

The indirect tax levied in India on the supply of goods and services, collected at each stage of the chain. A registered plumber charges it on bills and files periodic returns.

The set of attitudes and habits that guide behaviour at work, such as punctuality, honesty, responsibility and respect for customers and colleagues. Strong work ethics build trust and repeat business.

Passing on clear, timely and accurate information to a supervisor, customer or team member, in speech, writing or by phone. Good reporting prevents mistakes, delays and disputes on site.