The loss in pressure of a liquid flowing
through a piping system caused by friction of pipe and
fittings, velocity, and change in elevation.
PSI or PSIG. Abbreviation for pounds per square inch, the
PSIA. Pounds per square inch absolute; pressure above an
Radiograph. An image produced on radiosensitive film by
invisible radiation such as X-ray, specifically the image
produced by radiographic inspection of welds and plates.
Relational Database Management System.
Ready-Issue Tank. Storage tank from which fuel is issued
directly to the final-use vehicle such as a ship or aircraft,
sometimes called day tank or operating storage tank.
Recoverable Fuel. That portion of the fuel oil which may be
separated and collected from a given lot of contaminated fuel,
by proper processing in the treating facility in question.
Recovered Oil. Used to denote untreated petroleum fuel
removed from oil-water separators or picked up after being
spilled on land or water. Also used to mean oil which has
been separated from and collected from a given lot of con-
taminated fuel by processing in a treating facility.
Tank vehicles used to resupply aircraft with fuel.
conditions with the liquid temperatures at 100 F (38 C).
Residual Fuel Oil. Topped crude petroleum from refinery
operations. Commercial grades of Burner Fuel No. 5, No. 6,
and bunker fuels are residual fuel oils.
Relaxation Tank. Small tank in a fuel dispensing piping
system downstream of filter/separators or fuel quality
monitors designed to remove static electricity from the liquid