21 JANUARY 2003
Combustible vapor indicator. A device that measures the quantity of combustible vapors in the
atmosphere; also known as an explosive meter or LEL meter.
Confined space. A space that is large enough and configured so a worker can bodily enter and
perform assigned work, has limited or restricted means for entry or exit (e.g., tanks manholes, pits,
certain dikes), and is not designed for human occupancy.
to a petroleum product some material not usually
as dirt, rust,
water, or another petroleum product.
Corrosion. An electrochemical action causing a material to revert to its natural state (i.e., steel
corrodes to iron oxide [rust]).
Cut-and-cover tanks. Vertical storage tanks mounded over with soil. Used primarily in overseas
locations for concealment and splinter protection.
Dead head. A term used to describe the act of pumping against a closed pipeline.
Deadman control. A control device, such as a valve or switch, designed to interrupt flow if the
operator releases it.
De-energized. A term used to describe a component that has no electrical power applied to it.
. Any undesirable chemical
change that takes
place in a petroleum product
while in storage or in use.
Differential pressure (DP). The difference between high and low pressure. F/Ss use DP gauges to
sense the condition of the filter elements.
Differential pressure transmitter (DPT)
. A device that senses
and low pressure
as created by a venturi or orifice plate, converts the differential pressure (DP) into an electrical signal,
and sends the electrical signal through a wire.
Downstream. A term used to describe the direction of flow in a pipeline in reference to an object.
Downstream is the direction the fuel is moving. Downstream of the pump would be anywhere after the
Enable. The ability of an automatic valve to open when the conditions of its components are met.
Energized. A term describing a component that has electrical power applied to it.
Epoxy coating. A coating of thermosetting resins having strong adhesion to the parent structure,
toughness, and high corrosion and chemical resistance.
Explosion proof. Classification of electrical enclosures for use in hazardous areas designed to prevent
the passage of internal arcs, sparks, or flames.
Filter/separator (F/S). A fuel system component used to remove solid particles and water from the
Flammable liquid. Any liquid having a flash point below 38 C (100 F) and a vapor pressure not
exceeding 40 pounds per square inch absolute at 38 C (100 F).
Flash point. The temperature at which a combustible or flammable liquid produces enough vapor to
Floating roof tank. Petroleum storage tank with a roof that floats on the liquid surface, and rises and