Punjab PSEB Matric NSQF Plumbing (Assistant Plumber) flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Pipe wrench jaw direction

The jaws bite only when the handle is pulled toward the pipe. Pushing the handle the other way releases the grip and can round the fitting flats.

Hacksaw blade pitch choice

Use 18 teeth per inch for thick-wall and large pipe, 24 for general plumbing work, and 32 for thin-wall copper or tubing to avoid snagging and torn teeth.

Nominal bore (NB)

A nominal size label such as 15, 20 or 25 mm used for GI pipe. It is neither the outside nor the inside diameter, so measure the actual pipe to identify it.

BSP taper thread

A screwed pipe thread that tapers about 1 in 16 along its length. The taper wedges into the fitting and seals when jointing compound or PTFE tape is applied.

Solvent cement jointing steps

Cut square, deburr, clean with primer, apply cement to pipe and socket, push fully home with a quarter turn, hold briefly, then cure before pressure testing.

Dielectric union purpose

A fitting with an insulating washer that separates dissimilar metals, such as copper and galvanised steel, so galvanic corrosion does not destroy the joint.

Direct water supply system

Mains pressure feeds every tap directly with no storage tank. It needs adequate residual mains pressure and fails completely when the supply is cut.

Indirect water supply system

The mains fills an overhead storage tank, which then feeds outlets by gravity. It gives storage during cuts but needs sufficient tank height for pressure.

Overhead tank fittings

A service tank needs a float-valve inlet, an overflow pipe discharging visibly, a washout drain, a tight lid and access for cleaning, plus a vent.

Water hammer cause

A pressure surge when a fast-closing valve stops flowing water suddenly. Loose clips and long runs worsen it; an arrestor or slower-closing valve reduces it.

Trap seal depth

The depth of water held in a trap that blocks sewer gas. Design value is about 50 mm; below 25 mm the seal is unreliable and gas can enter.

Dual flush cistern

A WC cistern offering two flush volumes, commonly 6 litres full and 3 litres reduced. The reduced flush saves water for liquid waste only.

Fixture waste pipe sizes

Wash basin waste is 32 mm, sink waste 40 mm and WC soil connection 100 mm. Trap and branch sizes must match the fixture outlet.

Anti-siphon protection

An air gap or vacuum breaker fitted so that backflow cannot siphon contaminated water into the supply. Required on flush valves and submerged outlets.

One-pipe drainage system

Soil and waste discharge into a single vertical stack, with waste branches connected above the highest soil entry so fouling does not reach them.

Drain gradient rule

A 100 mm drain is laid at about 1 in 60 to 1 in 100. Too flat allows silting, too steep leaves solids behind as the liquid runs ahead.

Inspection chamber spacing

Chambers are placed at every change of direction, gradient or size, typically every 45 m on 100 mm drains and every 90 m on 150 mm and larger.

Vent stack function

A pipe open above roof level that equalises air pressure in the drainage stack, preventing trap seals from being sucked out by siphonage.

Drain leakage test

Plug the low end, fill the drain to the highest branch, mark the water level, wait at least 30 minutes and check for a fall in level or visible leaks.

Supply pipe pressure test

Isolate the new section, fill and expel air, raise to 1.5 times working pressure, hold one hour and check every joint with soap solution.

Thread length rule

Cut the thread long enough to fill the socket plus two or three exposed threads. Too long bottoms in the fitting; too short gives weak engagement.

Copper bend radius rule

Minimum bend radius for annealed copper is about three to four times the outside diameter. Hard temper copper must be annealed or bent with a bender.

Bend allowance formula

For a 90-degree bend, the allowance along the centre line is roughly 1.57 times the bend radius. Add it to the straight lengths to get total pipe needed.

Confined space entry rule

A manhole or septic tank requires atmosphere testing for oxygen and toxic gas, a harness and lifeline, and a standby person outside before anyone enters.

Ladder 4 to 1 rule

Set the ladder base one metre out for every four metres of height, secure the top, keep three points of contact and never overreach sideways.

Solvent cement hazards

Primer and cement are flammable and give off harmful vapour. Use only with good ventilation, away from flame, and keep containers closed when not in use.

Drawing scale reading

On a 1:50 drawing, one millimetre measured equals fifty millimetres real. Multiply the scaled measurement by the scale denominator to get the actual size.

Costing formula for a job

Total equals material cost plus labour hours times rate, plus overheads and profit. Add the applicable tax percentage to reach the final quoted price.

Cutting waste allowance

Add roughly five to ten percent to the measured pipe length for bends, offsets and offcuts. Fittings are counted individually, not by length.

Estimate versus quotation

An estimate is an approximate figure that may change with conditions. A quotation is a fixed offer, so always state clearly which one you are giving.

Tax invoice essentials

A valid tax invoice shows the supplier GSTIN, a unique invoice number and date, item description, taxable value, tax rate and the total amount payable.

Job card record

A job card notes customer details, date, complaint, work done, parts used, cost and both signatures. It supports warranty claims and repeat business.