21 JANUARY 2003
Orifice plate. A component used to create a differential pressure for use in controlling automatic
Panero system. Type I fuel system. Single-outlet hydrant system.
Pantograph. A series of pipes, connected by swivel joints, used to connect fueling equipment to
aircraft or vehicles.
Petroleum. A compound consisting of a mixture of hydrocarbons.
Phillips system (constant-pressure system). Type III system. Constant pressure fueling system with
multiple hydrants in the parking apron. Piping is arranged in a loop.
Pontoon roof. Floating roof for a storage tank that has liquid-tight compartments with positive
Power. A source or means of supplying energy. The time or rate at which work is done or energy is
transmitted or emitted.
Pressure. The force exerted over a surface divided by its area.
Pressure drop. The loss in pressure of a liquid flowing through a piping system caused by pipe
friction, fittings, velocity changes, and changes in elevation.
Pressure indicating transmitter (PIT)
. A device used
pressure, convert the pressure
electrical signal, and send the electrical signal through a wire.
Pressure gauge. An instrument used to measure pipeline pressure at the point where it is installed.
Some gauges can read differential pressure (DP) and some can read vacuum.
Pressure surge/spike (hydraulic shock). Sudden increase in fluid pressure caused by a sudden stop of
Pritchard system. Type II fuel system. Multi-outlet hydrant system.
Refueler. Tank tuck used to resupply aircraft with fuel.
. An opposing
or retarding force; the opposition offered
by a body
Sludge. Heavy viscous oily mass found in the bottom of storage tanks; often contains rust, scale, or
Specific gravity. The ratio of the weight of a given volume of material at 15.5 C (60 F) to the weight
of an equal amount of distilled water at the same temperature, both weights being corrected for the
buoyancy of air.
Stability. Property of product that gives it the ability to retain its physical and chemical properties
intact, even during extended storage.
Static dissipater additive (SDA). An additive that reduces static discharge potential in the vapor space
above the fuel. It reduces the time for static charges to dissipate, decreasing the potential for ignition
from static charges.
. An electrical
by objects rubbing together, creating negative
Strapping. Measuring storage tanks and cargo carriers for capacity.