Hvac 50 B Every Test Questions Flashcards
To review questions from the entire course
An example of a pressure vessel is
A cylinder containing refrigerant
A fusible plug is a metal fitting that has a hole drilled through it and the hole is filled with
Material with a low melting point
What it is necessary to perform electrical work in an area that has a damp or wet floor, what can be done to minimize the chance of electrical shock ?
Place a rubber mat on the floor, use a wooden ladder, and wear insulated boots and gloves.
Electrical power should always be shut off at the _______ or entrance panel and locked out in an approved manner when installing equipment.
Distribution
A double insulated drill is
Generally has a plastic case with the electrical connections and motor insulated within the tool
In electrical circuits, the ______ wire protects the operator.
Grounding
Fires that involve ordinary materials such as paper, cardboard, and wood are classified as type _______ fires.
A
Fires that involve ordinary materials such as oil and gas are classified as type _______ fires.
B
Fires that involve electrical equipment are classified as type ______ fires.
C
Fire extinguishers that can be used on any type of fire, A,B, or C generally contain a _________ to extinguish the fire.
Dry chemical powder
True or false : when working in a machine room, safety glasses should NOT be worn because they can fog up and impede your eyesight.
False
True or false: It is possible that your hand would suffer frostbite if it comes in contact with liquid R-22 when accidentally releasing refrigerant into the atmosphere(an illegal procedure)
True
True or false : As long as the torch is kept moving below the level of the liquid refrigerant in the cylinder so as not to create hotspot, it is OK to heat the cylinder in this manner.
False
To insure proper operation of an oxygen cylinder regulator, make sure no oil residue is present.
True
Aluminum ladders are safe to use around electrical equipment as long as they have insulation pads on the bottom of the rungs.
False
True or false : A necessary safety practice for a technician is to lockout the panel with a padlock and keep the key with you.
True
True or false : if you are a refrigeration technician, a warm coat and gloves should be in your truck, even in the middle of the summer.
True
Oil must never be used around a(n)________ cylinder.
Oxygen
Power tools that are not double insulated must have 3-prong plugs to ensure that the tool is properly ________.
Grounded
A way to move equipment across a roof is to use rollers and ________ for a base.
Plywood
When referring to large refrigerant or nitrogen tanks and recognition must have
The protective cap MUST be on when the tank is not in use.
Safety goggles or glasses must be worn when moving the tank.
Large tanks should not be carried, they should be secured to an approved cart.
wiring and crimping tool is used to
cut and strip wire
Air-conditioning and refrigeration reversible
ratchet box wrenches are used to
tighten hex head screws on refrigeration
cabinets
flare nut wrenches are used to
tighten or loosen nuts over tubing flares.
Tube cutters are used to
cut iron pipe used for natural gas.
The gauge manifold is a very important piece of
equipment for the air-conditioning and
Refrigeration technician; it may include
a four-valve design, including separate valves
for the vacuum, low-pressure, high-pressure,
and refrigerant cylinder connections
The charging cylinder is used
to measure the refrigerant charge into
a refrigeration system.
A sling psychrometer is used
To measures the air velocity in a duct system.
A draft gauge is used to
determine the carbon monoxide in flue gases.
A digital anemometer is used
To determines natural gas and propane
gas
The electronic vacuum gauge checks system
pressures
up to 5 psig.
Thermometers used in the field may be
electronic type
In flue gas installations the pressures for oil or gas may be checked to
a manifold gauge
True or false : An electronic leak detector or a microfoam solution can be used while the unit is running.
True
Which type of tubing or piping would be used for
natural gas on a gas furnace?
Type L copper
Types K and L copper tubing have different
wall thickness
When tubing is cut with a tubing cutter, a ________
is often produced from excess
material pushed into the end of the pipe from
the pressure of the cutter
Burr
The maximum temperature at which soldering
(soft soldering) is done is about
842 F
Brazing is done at ________
soldering
higher temperatures than
A common filler material used to solder lines
containing potable water is composed of
15%-60% silver.
A common filler material used for brazing is
composed of
50/50 tin-lead
What heat sources is often for soldering and brazing
Natural Gas
A flux is used when soldering to
allow the tubing to fit easily into the fitting
When soldering or brazing, the filler metal is melted by
heat from the tubing and fitting.
a flare joint
uses a flare on the end of a piece of tubing soldered to a flare on a mating piece of tubing.
A swaged joint
is made by expanding one piece of tubing to fit
over another piece of tubing of the same diameter
is made by expanding one piece of tubing to fit
over another piece of tubing of the same diameter
What is a Steel pipe joined with
It is joined with threaded fittings.
In the thread specification1/2 -14 NPT
the 14 stands for
number of threads per inch.
The end of a piece of steel pipe is reamed after it
is cut
to remove the burr from the inside of the pipe.
Plastic pipe is often used for
plumbing, venting, and condensate applications.
What does a vacuum pump do ?
removes gas molecules from a sealed volume
The tool used to create internal threads is called a
Tap
The size indicated for the diameter of copper tubing used for plumbing is the
Inside diameter
The size indicated for the diameter of ACR copper tubing is the
Outside diameter
Filler materials used in te high temperature connection of copper joints are composed of
15%-60% silver
Molten solder flows between the 2 base metals being soldered because
Of capillary attraction
The proper type of flame from an oxyacetylene torch for silver brazing is
Neutral flame
For cleaning ACR copper tubing before soldering, a material that can be used is
Sand clothe
Pipe threads are standardized by the ANS. ANS stands for
American national standard
Pipe threads, when used on pipe that will contain liquid or vapor under pressure,
Generally have a v shape
When joining steel pipe, a ______ should be applied to the threads before connecting.
Pipe dope
T or F: k type copper is heavy duty with thick tubing wall ?
True
T or F: L type copper is considered medium weight and is used most frequently.
True
T or F: M is a lightweight copper and is not commonly used in our industry.
True
Luis make a card
Ok I will
Two types of tube benders are
pipe and plastic.
Never use _______ or _______ to raise the pressure in a refrigeration system.
pure oxygen or air
