Page 48 - igem-g-4 edition 2_Neat

IGEM/G/4 Edition 2
ventilation
Movement of air and its replacement with fresh air due to the effects of wind, temperature
gradients, or artificial means, for example fans or extractors.

ventilator
Opening, often with a security grille, used for ventilation.

venting
Discharge of gas (or, when purging, other mixtures) from gas plant to atmosphere.
 vent line Device for conducting relief, bleed or fault gas away from gas plant, usually to
atmosphere
 vent Equipment aperture that vents gas
 vent pipe A pipe, usually vertical, used to vent gas to atmosphere, i.e. a vent line.
Alternatively, a vent pipe may be a pipe containing vent lines and breather
lines.

vent valve
Valve having the same performance requirements as a safety shut-off valve (SSOV) and used
as part of a SSOV proving system to prove the effective closure of the main SSOVs.

volumetric regulator
Regulator which maintains a pre-set volume flow rate, irrespective of pressure.

washover pipe
Rotating drill pipe of larger diameter than the pilot drill and placed around it with its leading
edge less far advanced.

waterborne accommodation (see also “permanently moored boat”)
A permanently or temporarily occupied floating domestic accommodation vessel that is
designed to be permanently moored to a fixed berth, and is not fitted with an onboard gas
supply. A means of propulsion may or may not be fitted.

waterless gasholder
Low pressure gasholder in which the moving parts are sealed by other methods than water.

watersealed gasholder
Low pressure gasholder in which water plays an essential part as a sealing medium.

wayleave
Right of way over another’s ground or property, rented to the owner of a pipeline.

weep by-pass pressure proving system
System which proves that burner gas isolation valves are closed immediately prior to the start
of an ignition sequence by pressurizing the pipework to the burner gas isolation valves
through a restricted by-pass around the safety shut-off valve(s) (SSOV(s)).

weldability
Ability of a material to be welded satisfactorily.

weldolet
Forged fitting, of the saddle type, enabling the fabrication of a fully welded branch connection.

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