Page 678 - The City and Guilds Textbook: Plumbing Book 1 for the Level 3 Apprenticeship (9189), Level 2 Technical Certificate (8202) and Level 2 Diploma (6035)

Glossary

Acceleration: a measure of the to employers and employees on all water will drop but the velocity of
rate at which an amount of aspects of workplace relations and the water increases. When the pipe
matter increases its velocity. It is employment law. increases back to its original size,
measured in a change of velocity Advisory: recommended but not then the velocity will decrease and
over a period of time and, as such, enforced. the pressure will increase almost to
is directly proportional to force. It its original pressure.
will increase and decrease linearly Aesthetically pleasing: beautiful Boiler cycling: the process of the
with an increase or decrease in in appearance, good-looking, constant firing up and shutting down
force if the mass remains constant. in keeping with the rest of the as the system water cools slightly
It is measured in metres per second surroundings. wastes a lot of fuel energy. Applied to
squared (m/s ). Air infiltration: a process where air when a heating system has reached
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Acceleration due to gravity: the can get into a system and cause air temperature, the boiler shuts down
rate of change of velocity of an locks and corrosion. on the boiler thermostat. A few
object due to the gravitational pull Amp (and milliamp): unit minutes later the boiler will fire up
of the Earth. If gravity is the only of electrical current, the again to top up the temperature as
force acting on an object, then the measurement of ampere. the system loses heat and, after a few
object will accelerate at a rate of seconds, shuts down again.
9.81 m/s downwards towards the Annealing: a process that involves Boiler interlock: ‘locking out’ on
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ground. heating the copper to a cherry-red
colour and then quenching it in the overheat high-limit thermostat.
Accent: the way in which people water. This softens the copper tube BSP: British Standard Pipe.
pronounce their words. so that the copper can be worked
Accident: an unexpected or without fracturing, rippling or BSPT: British Standard Pipe Thread;
the type of thread used on screwed
unplanned event that could result deforming. low carbon steel pipes and fittings.
in personal injury, damage and, Anodising: coating one metal with
occasionally, death. When an another by electrolysis to form a Calorific value: the amount
accident occurs, there are always protective barrier against corrosion. of energy stored in the gas in
reasons for it and if there’s a reason, its uncombusted state. It is
then there is usually blame. Asbestos: a fibrous silicate material the amount of energy released
highly resistant to heat. when the gas is combusted. It is
Actual capacity: (of a cistern) the measured in megajoules (MJ) per
maximum volume it could hold Atom: a fundamental piece of cubic metre or MJ/m .
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when filled to its overflowing level. matter made up of three kinds of
particles called subatomic particles Centre to centre: measuring from
Acute injury: occurs when manual – protons, neutrons and electrons. the centre line of one pipe to the
handling or lifting causes centre line of another, so that all
immediate pain and injury. Benchmarking: this is now a
compulsory requirement to ensure the tube centres are uniform. This
Adhesion: the way in which that systems and appliances are ensures that the pipework will look
water molecules ‘stick’ to other installed in accordance with the perfectly parallel because all of
molecules they come into contact regulations and the manufacturer’s the tubes will be at equal distance
with. instructions. It also safeguards from one another.
Advisory, Conciliation and any guarantee against bad Chamfer: to take off a sharp edge
Arbitration Service (ACAS): an workmanship. at an angle. If we chamfer a pipe
organisation that provides free and Bernoulli’s principle: when a pipe end, we are taking the sharp,
impartial information and advice reduces in size, the pressure of the square edge off the pipe.

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