 | Back EMF - The emf that opposes the
normal flow of current in a circuit.
|
| Back Pressure - This is the
refrigerant pressure in the low side of the system also called low side
pressure or suction pressure.
|
| Baffle - A device used to divert the
flow of a substance (air or liquid).
|
| Balanced Pressure - when the both the
inside and outside pressure of a container equal each other.
|
| Barometer- is used to measure
atmospheric pressure.
|
| Barometric Damper - Also called draft
damper, is a device installed in a chimney to allow for the adjustment of
dilution air.
|
| Bearing - mechanical device for decreasing friction in a machine
in which a moving part bears—that is, slides or rolls while exerting force—on
another part. Usually in a bearing the support must allow the moving part
one type of motion, for example, rotation, while preventing it from moving
in any other way, for example, sidewise. The commonest bearings are found at
the rigid supports of rotating shafts where friction is the greatest.
|
| Bellows - A corrugated cylindrical
container which moves with a pressure change.
|
| Belt - A rubber like, continuous loop
placed between two or more pulleys to transfer a rotary motion.
|
| Bernoulli's Theorem - In stream of
liquid, the sum of elevation head, head pressure, and velocity remains
constant along any line of flow, provided no work is done by or upon liquid
on course of its flow ; decreases in portion to energy lost in flow.
|
| Bimetal - A temperature regulating or
indicating device which works on the principal that two dissimilar metals
with unequal expansion rates, welded together and will bend as their
temperature changes.
|
| Blast Freezer - A low -temperature
evaporator that uses a fan to force air rapidly over a evaporator surface.
|
| Bleed-Valve - A valve with a small
opening witch permits a minimum fluid flow when the valve is closed.
|
| Blend - A mixture consisting of two or
more single components.
|
| Blower - similar to a fan used to push air
|
| Boiler - device
for heating water or generating steam above atmospheric pressure.
|
| Boiling Point- The
point at witch a substance will vaporize if anymore heat is added.
|
| Boiling temperature -
Temperature at witch a fluid changes from a liquid to a gas.
|
| Booster - A term used
for the first stage compressor in a cascading system.
|
| Bore - The inside
diameter of a cylinder.
|
| Boyle's Law - Boyle’s law states that the
volume of a given amount of gas varies inversely with its pressure, if
temperature is constant. This means that at a constant temperature, the
pressure of a gas will increase as the volume of the gas is decreased.
|
| Brazing - a method of joining two metal surfaces
by using nonferrous filler metal heated to above 430° C (800° F), but
below the melting point of the metals to be joined.
|
|
BTU - British Thermal Unit - The amount of heat energy required to raise the temperature of one pound of
water by one degree Fahrenheit.
|
|
Bridge rectifier - A full-wave rectifier
in which there are four arms - each containing a diode.
|
|
Brine - A salt water mixture commonly used as a secondary
refrigerant.
|
|
Burner - A device in which the burning
of fuel takes place.
|
|
Bypass - The passage at one side of or
around a regular passage.
|
