CEA 4001 - Page 22

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installation, pre-action
One of two types of dry, or alternate in dry mode, installation in which the alarm valve can be opened by an
independent
fire detection system in the protected area.
installation, wet (pipe)
An installation in which the pipework is always charged with water.
jockey pump
A small pump used to replenish minor water loss, to avoid starting an automatic suction or booster pump
unnecessarily.
life safety
A term applied to sprinkler systems forming an integral part of measures required for the protection of life.
looped configuration
A pipe array in which there is more than one distribution pipe route along which water may flow to a range
pipe.
main
distribution pipe
A pipe feeding a distribution pipe.
maximum flow demand (Qmax)
The flow at the point of intersection of the pressure-flow demand characteristic of the most favourable area
of operation and the water supply pressure-flow characteristic with the suction source at its normal water
level.
mechanical pipe joint
A pipe fitting other than threaded tubulars, screwed fittings, spigots and socket and flanged joint, used to
connect
pipes and components.
multiple control
A valve, normally held closed by a temperature sensitive element, suitable for use in a deluge installation or
for
the operation of a pressure switch.
multi-storey building
A building comprising two or more storeys, above or below ground.
node
A point in pipework at which pressure and flow(s) are calculated; each node is a datum point for the purpose
of hydraulic calculations in the installation.
pipe array
The pipes feeding a group of sprinklers. Pipe arrays may be looped, gridded or branched.
pre-calculated
A term applied to an installation in which the pipes down-stream of the design point(s) have been previously
sized
by hydraulic calculation. Tables of diameters are given.
range pipe
A pipe feeding sprinklers either directly or via arm pipes.
riser
A vertical distribution pipe feeding a distribution or range pipe above.