Topics: All categories in the pool
1: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
2: The two float-type metering devices are the
- high-side float and the low-side float
- vapor float and the low-side float.
- liquid float and the vapor float
- liquid float and the low-side float
3: A water regulating valve opens when
- the compressor is on
- when the power is on there is an overcharge of refrigerant
- the head pressure rises
- when the power is on
4: A class B1 refrigerant is considered
- toxic but non-flammable
- toxic and somewhat flammable
- non-toxic but highly flammable
- non-toxic and non-flammable
5: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UL and UR
- UL and UM
- UV or UR
- UM or UL
6: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
7: The actual expansion curve of compressor follows most nearly which one of the following
- Pressure-Temperature
- Adiabatic
- Volume
- Isothermal
8: _____ and its alloys are suitable for use with ammonia systems.
- Aluminum
- Copper
- Zinc
- Magnesium
9: All low-pressure chillers use which type of compressor?
- Centrifugal
- Reciprocating
- Scroll
- Rotary
10: Pressure limiting devices are not required for systems containing less then ________ refrigerants.
- 22 lbs
- 6.6 lbs
- 13.9 lbs
- 44 lbs
11: On a ammonia compressor, the pressure of a forced fed oil pump is changed by varying the
- adjustment of the spring tension of the TXV
- cooling temperature set-point
- opening at the pump inlet
- opening at the pump outlet
12: A thermometer inside a duct measures ____ heat.
- specific
- latent
- sensible
- hidden
13: Defined process piping by code CMR (528)
- Any piping that conveys a solid, liquid or gas that is not part of the plumbing or fire protection system
- Any piping in an industrial space
- Any piping in an industrial or commercial space
- All of the above
14: Each machinery room shall contain
- smoke and fire alarms as well as three means of egress and that egress must meet 528 CMR ventilation requirements
- a refrigerant detector located in an area where the refrigerant from a leak will concentrate
- high and low pressure controls
- a toxicity detector where the presence of ammonia or lithium bromide from a leak will concentrate
15: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- specific heat
- lost heat
- sensible heat
- latent heat
16: What would be the classification of a prison?
- Large mercantile
- Institutional
- Place of assembly
- Industrial
17: What is NOT a positive displacement compressor.
- Scroll
- Reciprocating
- Rotary
- Centrifugal
18: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- 1.2
- .8
- .1
- 1.7
19: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
20: With a 5/8" X 5/8" x 3/4" tee, what size is the center connection?
- 5/8"
- 1/2"
- 3/8"
- 3/4"
21: Halogen refrigerants are corrosive to which type of metal?
- copper
- stainless steel
- black iron
- magnesium
22: A halide torch is most useful with a freon compression system
- to remove from from TXV's and evaporator coils
- to sweat flanges on the refrigeration piping
- to release a sticking valve
- to detect refrigeration leaks in piping joints
23: Joints in refrigeration piping must be _____ before being covered?
- Inspected
- Pressurized
- Leak tested
- Insulated
24: When energized, a normally open relay will be
- noisy
- depends on the type and class of the relay
- open
- closed
25: When air is ducted through a machine room that services occupied space, What must be done?
- Flanged and gasketed
- Insulated and cross broke
- Welded and seamed.
- Ducted and sealed