Radial Compressor
|
A
compressor belonging to the group of dynamic compressors and characterized
by radial flow. (Centrifugal). |
Ram
|
The amount of
pressure build up above ambient pressure at the engine's compressor inlet,
due to forward motion of the engine through the air - air's initial
momentum. |
| Rated Capacity |
Volume rate of air flow at rated pressure at a specific
point. |
| Rated Pressure |
The operating pressure at which compressor performance is
measured. |
| Rebound |
The extension of
an air actuator beyond its design height. |
Receivers
|
Tanks or
vessels used for the storage of gas (air) under pressure discharged from
compressors and also to dampen discharge line pulsations.
In a large compressed air system there may be primary and secondary
receivers. |
Reciprocating Compressors
|
Compressors in which the compressing element is a piston having a
reciprocating motion in a cylinder. |
Recovery Pressure
|
Pressure of either motive fluid or discharge at which an ejector returns to
stable operation following a period of unstable operation due to having
previously reached the breaking pressure. There are two recovery pressures,
one for motive fluid and one for the discharge pressure. |
| Reduced Pressure |
Ratio
of the pressure of a gas to its critical pressure, in like units.
|
Reduced Temperature
|
The
ratio in absolute units of the actual gas temperature to the critical
temperature. |
Refrigerant
|
Media of
heat transfer in a refrigeration unit; whereas, R12 and R22 are commonly
used refrigerants. |
Refrigeration Dryer
|
A device consisting of a heat transfer system, a moisture elimination system,
and a refrigeration system designed to improve the quality of the air and
reduce the temperature of the air. |
Regeneration
|
The process of desiccants being regenerated by water being driven off the
desiccant by hot air or gas passing through the desiccant bed, and, thus, heating it. As a
result, the partial pressure of the water vapor becomes higher than that in
the regenerating air. Water is, therefore, released from the desiccant and
carried away with the air stream (purge air) until a new state of
equilibrium is reached. |
Regulator
|
An automatic or manual device designed to control pressure, flow, or
temperature. |
Reheaters
|
Heat
exchangers for raising the temperature of compressed air to increase its
volume. |
Relative Clearance Volume
|
The ratio of clearance volume to the volume swept by the compressing
element. |
Relative Humidity
|
The
ratio of the actual water-vapor partial pressure to vapor saturation
pressure at the same temperature (dry bulb) within atmospheric air
conditions. |
Relative Vapor Pressure
|
The ratio of vapor pressure to the saturated vapor pressure at the
temperature considered. |
Relief Valve
|
A spring
loaded pressure relief valve actuated by the static pressure upstream of the
valve. The valve opens normally in proportion to the pressure increase over
the opening pressure. |
Required Capacity
|
Cubic feet per minute (cfm) of air required at the inlet to the distribution
system. |
Reversible Process
|
An ideal frictionlesss process that may be stopped and made to retrace its steps and
restore to the systems or surroundings all work and heat previously removed. |
Reynold's Number
|
A dimensionless flow parameter, ( Jnr/m), in which "J" is a significant
dimension, often a diameter, "n" is the fluid velocity, "r" is mass density, and
"m" is dynamic viscosity, all in consistent units. |
Rings
|
Circular metallic elements that ride in the grooves of a piston and provide
compression sealing during combustion which are also used to spread oil for
lubrication. |
Ring Sticking
|
The
freezing of a piston ring in its groove in a piston engine or reciprocating
compressor due to heavy deposits in the piston ring zone. |
| Rock Drill |
A pneumatic
percussive drill designed as a boring tool. |
| ROI |
Return on
investment. |
| Rolling Element |
A type
of journal bearing in centrifugal air compressors. |
| Rotary Actuator |
A pneumatic device with a rotary output and is typically of a vane or
rack-and-pinion construction. |
Rotary Blowers
|
A compressor belonging to the group of displacement rotary compressors; a
type of valve less displacement machine; also referred to as "Roots blower". |
Rotary Compressors
|
Machines in which compression is affected by the positive action of rotating
elements. |
| Rotary Sliding Vane Compressors |
Machines in which axial vanes slide radially in an eccentrically mounted
rotor. |
Rotor
|
The rotating element of a machine and, in the case of a compressor, is
composed of the impeller(s) and shaft, and may include shaft sleeves and a
thrust balancing device. |
| Rust Prevention Test
(turbine oils) |
A test for determining the ability of an oil to aid in
preventing the rusting of ferrous parts in the presence of water. |
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