NOZZLE --A taper or restriction used to
pump and its output shaft lever. It is mechanically
speed up or direct the flow of gas or liquid.
connected to the MFC power lever. The PLA
actuator supplies the torque to position the MFC
OIL DISTRIBUTION (OD) BOX--This box
power lever at the commanded rate.
is located at the forward end of each MRG
assembly. It directs HP oil from the HOPM to
POWER TURBINE (PT)--The GTE turbine
the propeller hub through the shaft bore. The OD
that converts the GG exhaust into energy and
box also establishes propeller pitch by using
transmits the resulting rotational force via the
control oil from the HOPM to position the valve
attached output shaft.
rod, which extends through the shaft to the hub.
POWER TAKEOFF (PTO)--The drive shaft
ORIFICE --A circular opening in a flow
between the GTGS GTE and the reduction gear.
passage that creates a flow restriction.
It transfers power from the GTE to the reduction
gear to drive the generator.
PARAMETER --A variable, such as temper-
ature, pressure, flow rate, voltage, current, or
PRAIRIE AIR SYSTEM--This system emits
frequency that may be indicated, monitored,
cooled bleed air from small holes along the leading
checked, or sensed in any way during operation
edge of the propeller blades. The resulting air
or testing.
bubbles disturb the thrashing sound so identifica-
tion of the type of ship through sonar detection
PERMANENT MAGNET ALTERNATOR
becomes unreliable.
(PMA)--The PMA is mounted on the generator
shaft extension of each GTGS and supplies speed
PRESSURE --Force per unit of area, usually
sensing and power to the EG. The PMA also
expressed as psi.
supplies initial generator excitation.
PRIME MOVER--( 1) The source of motion--
as a GTE, (2) the source of mechanical power used
PHOTOELECTRIC--Electricity produced by
the action of light.
to drive a pump, or compressor, (3) or rotor of
a generator.
PITCH--A term applied to the distance a
propeller will advance during one revolution.
PROPELLER --A propulsive device consisting
of a boss or hub carrying two or more radial
blades. (Also called a screw.)
PLENUM CHAMBER--An enclosed space
in which the pressure of the air is greater than the
outside atmosphere.
PROPULSION AUXILIARY CONTROL
CONSOLE (PACC)--This console is located in
POTENTIOMETER--A variable resistance
CCS and is part of the PAMCE. It contains the
unit having a rotating contact arm that can be set
electronic equipment capable of controlling and
at any desired point along the resistance element.
monitoring both propulsion plants and auxiliary
equipment on a CG- or DD-class ship. (Also
POWER TURBINE INLET TOTAL PRES-
known as PACC on the DDG-51 class ship but
not a part of PAMCE.)
SURE (Pt 5 . 4 )--The pressure sensed by pressure
probes located in the GTE turbine midframe and
PROPULSION AND AUXILIARY MACHIN-
piped to a transducer on the bottom of the GTM.
ERY CONTROL EQUIPMENT (PAMCE)--
POWER TURBINE INLET GAS TEMPER-
This equipment is located in CCS, is part of the
ECSS, and includes the PACC and PACEE. This
ATURE (T5.4)--The temperature sensed by
equipment provides centralized control and
thermocouples installed in the GTE midframe.
monitoring of both main propulsion plants and
POWER TURBINE SPEED (Np t)--The
auxiliary machinery on a CG- or DD-class ship.
speed sensed by magnetic pickups in the GTE
turbine rear frame.
PROPULSION AND AUXILIARY MACHIN-
ERY INFORMATION SYSTEM EQUIPMENT
POWER LEVEL ANGLE (PLA)--A rotary
(PAMISE)--This equipment is located in CCS
and is part of the ECSS. This equipment receives,
actuator mounted on the side of the GTE fuel
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