To Pull a vacuum means
lower the pressure in a refrigeration system below atmospheric
A compound gauge
all the above
which if the following represents the lowest vacuum
1000 microns
A multiple evacuation means that
you pull a vacuum on a refrigeration system more than once letting a little gas back in each time
how many chlorine atoms does it take to destroy 100,000 ozone molecules
1
the ozone depletion factor of R-12 is
1.0
which of the following refrigerants is considered HFC-type
R-134a
Whats the abbreviation for a refrigerant with chlorine, fluorine, carbon and hydrogen
HCFC
Refrigerants that are made up of two refrigerants with the correct proportions, combine to make a third stable refrigerant are called
azeotropes
to clean refrigerant by use of a filter dryer is called
recycle
refrigerant in vapor form is normally put into the system through
the suction line
when charging a system with vapor refrigerant from a refrigerant cylinder, the cylinder will become
cold
a graduated cylinder charging device is a device that
all the above
There are _____ microns in 1 mm Hg
1,000
A deep vacuum involves reducing the pressure in a refrigeration system to a micron gauge reading of ____ or below
500 microns
Refrigeration that damages the ozone layer contains an element called
chlorine
production of CFC refrigerants became illegal on January 1 _______
1996
the smallest amount of refrigerant released when removing gauge hoses from the system is called
Deminimus release
the DOT- approved cylinders in which refrigerant may be recovered has a mechanism for shutting the recovery system off when it reaches approximately _____% full
80
Refrigerant in vapor form is added to the system through the
low side
when the refrigerant cylinder is connected to an operating system, the pressure in the cylinder will be ______ than the suction pressure of the system
Higher
as refrigerant vapor is removed from a supply cylinder, they pressure in the supply cylinder will
fall
the charging device that holds refrigerant, has a visible column of liquid, and can be used to "visually" see the amount of refrigerant used is called the
graduated cylinder
why is refrigerant not used for a system standing pressure test
temperature relationship and it is illegal to vent into the atmosphere
a pressure of 100 microns has been reached with the vacuum pump operating. The pump is turned of and the gauge reading rises to 500 microns and stays there. What does this indicate.
Moisture free and leak tight
why must all valves be opened when an evacuation is preformed?
of there are any closed valves non-condensible gas could get trapped in the system
why is stratospheric ozone so important to our environment
it absorbs the ultra-violet rays from the sun
What is the difference between an azeotropic mixture and a near azeotropic mixture
azeotropic mixture has one boiling point and will not separate
near-azeotropic mixture has multiple boiling points and will separate