Oil and Gas: Terms & Glossary

Accumulator	Temporary storage tank for liquids and vapors
Actuator	A hydraulic or pneumatic apparatus that will operate a valve by remote control.
Air, compressed	Any air with pressure greater than atmospheric pressure
Air, instrument	Compressed air free of contaminants that is used to operate pneumatic control devices.
Air, plant	Compressed air used to drive pneumatic hand tools.
Air cooler	Large fan-type coolers placed above or below a pipe rack, which draws air across the pipes in the pipe rack to cool them.
Alarm	Signals, via lights or horn, used to indicate whether the liquid level, temperature, or pressure  inside a vessel is too high or too low or whether there is no flow or reverse flow.
Anchor	Stationary support designed to restrict the movement of a pipe caused by vibration, turbulence, expansion, or other external forces.
Anchor bolts	Bolts that have been positioned in concrete prior to curing. Used to secure equipment, buildings, tanks, or other items to a concrete foundation.
Area limit	Boundary identifying the extents of the unit being drawn.
Back-up ring	A 1/8" thick, washer-like, ring placed between two pieces of pipe to prevent the build-up of weld icicles inside the pipe during the welding process.
Ball valve	Valve having a ball with a hole through it that allows straight-through flow. A 90° turn of the wrench opens/closes the valves.
Base plate	Flat, metal plate welded to a vessel or other piece of equipment allowing it to be secured to a concrete foundation via anchor bolts.
Battery limit	Lines placed on a drawing to identify the perimeter limits of a unit.
Bent	One section of a pipe rack containing two vertical columns and one or more horizontal connecting members
Beveled end.	Any piping component having a tapered end used in butt-welding.
Billet.	Near-molten, steel bar from which seamless pipe is formed.
Bill of materials.	A detailed listing of components required to fabricate a run of pipe.
Blind flange	A flanged plate-like device used to terminate the end of a run of pipe, valve or vessel opening
Slowdown	Commodity discharged from a relief valve.
Boiler	Vessel used to convert water into super-heated steam.
Box heater	Vessel used to raise the temperature of a feed before it begins fractional distillation.
Branch	A connecting tie-in of the same or smaller pipe size.
Briddle	A screwed or socket-weld piping configuration containing instruments that measure the liquid level in horizontal or vertical vessels.
Bubble Caps	Small valve like controls on a tray in a fractionating column that allow rising vapors to pass through.
	Butt-weld. Weld made when two beveled ends are butted together and welded.
Bypass valve	Valve connecting the upstream and downstream sides of a control set that allows the control valve to be removed for repair or replacement.
By-product	Liquid fraction of raw crude.

Oil and Gas: A Practical Handbook