| ABSOLUTE PRESSURE |
The existing gauge
pressure, plus local atmospheric or barometric pressure. |
| AFTERCOOLER |
Heat exchanger for cooling
air or gas discharged from compressors. They provide the most effective means of
removing moisture from compressed air and gas. |
| CAPACITY |
Actual volumetric rate of
flow of gas compressed and delivered at conditions of total temperature, total pressure,
and composition prevailing at the compressor inlet. Expressed in cubic feet
per minute (CFM). |
| COMPRESSION RATIO |
The ratio of absolute
discharge pressure to the absolute inlet pressure. |
| COMPRESSOR |
The mechanical means for
compressing air or gas, thereby elevating the pressure. |
| DILATANT FLUIDS |
Liquids in which the
viscosity increases as agitation is increased. |
| DISCHARGE PRESSURE |
The absolute total
pressure at the discharge flange of a compressor. |
| FILTER |
Device for seperating and
removing dust, dirt, and entrained liquids from air. |
| FREE AIR |
Air at atmospheric
conditions at any specific location. Because of variations in altitude, barometer,
temperature, and humidity, this does not mean air under identical or standard conditions. |
| GAUGE PRESSURE |
Pressure in pounds per
square inch (or kilograms or square centimeter) above local atmospheric pressure. |
| INTERCOOLER |
Heat exchanger for
removing heat of compression between stages of a compressor. Also condenses and
removes a considerable amount of moisture. |
| NET POSITIVE SUCTION HEAD
AVAILABLE |
NPSHA - The
inherent energy in a liquid at the suction connection of the pump over and
above energy in the liquid due to its vapor pressure. It is characteristic of the
system and can be determined by calculation or test. It must be greater than the
NPSHR for the pump to operate correctly. |
| NET POSITIVE SUCTION HEAD
REQUIRED |
NPSHR - The
energy needed for the pump to fill on the suction side and overcome friction and flow
losses from the suction connection to the point in the pump where more energy is added.
NPSHR is a characteristic of the pump. It varies with pump design, size
and condition of service. It is determined by testing and is usually included on a
pump curve. |
| NEWTONIAN FLUID |
Liquids unaffected by the
magnitude or type of motion to which they are subjected. |
| PH VALUES |
The PH of a liquid is an
indication of its corrosive qualities, either acidic or alkaline. The scale of PH
value is from zero to 14 with 7 as a neutral point. |
| RECEIVER |
Tank used for the storage
of air discharged from compressors. They serve also to dampen discharge line
pulsation. |
| SLIP |
Loss in the delivery or
flow of a liquid from a pump due to the passage of the liquid through the pumping
components from the suction to the discharge. |
| SPECIFIC GRAVITY |
The ratio of a liquids
specific weight or density to that of a known liquid, such as water. |
| STANDARD AIR |
Air at a temperature of 680F.,
a pressure of 14.70 PSIA, and a relative humidity of 36%. This standard agrees with
both CAGI and ASME. |
| THIXATROPIC FLUIDS |
Liquids that exhibit a
decreasing viscosity with increased agitation. |
| VACUUM PUMP |
Compressors, which operate
with an intake pressure below atmospheric pressure, and discharge pressure usually at
atmospheric or slightly higher pressure. |
| VAPOR PRESSURE |
The pressure at which the
liquid is in equilibrium with the atmosphere or with its vapor in a closed
container. At pressures below vapor pressure at a given temperature the liquid will
start to vaporize due to the reduction in pressure at the surface. This is a major
factor in NPSH calculation. |
| VISCOSITY |
The measure of a liquids
resistance to flow. It is the friction resulting when one layer of fluid is made to
move in relationship to another layer. Temperature normally influences the viscosity
of a liquid. |
