Page 35 - igem-g-4 edition 2

IGEM/G/4 Edition 2
peak demand shaving
Gas held to supply “needle peaks” at times of severe weather, either within days or on a daily
basis.

pearson survey
Method of locating faults in pipe protective wrapping, by measurements taken at ground level
above the pipe and without excavating.

permanently moored boat (see also “waterborne accommodation”)
Vessel that is not used primarily for navigation, whether or not it is any person’s sole or main
residence.

permit to work
Formal written document used to control certain types of work that are potentially hazardous.

pig
Piston-like device, for example a steel frame and cup washers of rubber, neoprene or other
suitable material, such that compressed air, gas or water pressure will propel it along a
pipeline or pipework.

pig trap
Fabricated pipe fitting for inserting and removing pigs from a pipeline while in service.

piggable
Capable of passing a pig.

pilot bore
Creation of the first (usually steerable) pass of any boring process which later requires back
reaming or similar enlarging.

pilot burner
Small gas flame or main gas flame at a low burn rate for igniting gas at the burner ports.

pilot control
Auxiliary system that controls a main regulator or other device.

pilot flame
Start-gas flame established at a separate pilot burner which is utilized to ignite a main flame.

pilot fuel
Small quantity of oil injected into the cylinders of dual-fuel engines to cause ignition of the
gas/air mixture therein.

pipe and cable locator
Instrument used for the detection of buried metallic pipes and cables.

pipe array
Lengths of buried pipe laid in parallel within a controlled site, being manifolded together and
connected to a gas supply/discharge system via regulation equipment with or without
compressor facilities for the purpose of storing high pressure gas.

pipe jacking
Technique of installing a line of circular pipes into the ground by pushing from a fixed point
with hydraulic rams.

pipeline
System of piping with all associated equipment and stations up to the point of delivery.

31
©IGEM, IGEM House, High Street, Kegworth, Derbyshire, DE74 2DA. Website: www.igem.org.uk