FINAL PWEN ABSA PRACTICE 2 Flashcards
Connecting rods on a steam engine:
a. are used on double acting engines
b. are used to move the slide valve
c. are only needed on vertical engines
d. are used to connect the piston to the slide valve
e. connects the inlet valve to the discharge valve
a. are used on double acting engines
Diesel engines require:
a. a spark plug in each cylinder
b. a carburetor
c. a magneto
d. a fuel injector
e. an ignition distributor
d. a fuel injector
A collar thrust bearing:
- can support more load than a Michell thrust bearin
- can prevent a rotating shaft from moving in an axial direction
- has boundary lubrication
- is an antifriction type bearing
a. 1, 2, 3
b. 1, 2, 4
c. 2, 3
d. 3, 4
e. 1, 2, 3, 4
c. 2, 3
In an equivalent circuit developed from a multi-resistor series circuit:
a. the resistance will be the reciprocal sum of the original resistance’s
b. voltage drop will be the same as for each of the original resistance’s
c. the sum of voltage drops across the original resistance’s will be equal to the voltage drop of the equivalent circuit
d. original circuit resistance’s will each have to be the same as the equivalent resistance
e. amperage flowing will be different than the original circuit amperage glowing through each resistance
c. the sum of voltage drops across the original resistance’s will be equal to the voltage drop of the equivalent circuit
An air receiver used in an air compression system will perform the following functions:
- acts as a storage vessel
- eliminates pulsation in discharge lines
- separates out water from the air
- controls the temperature of the air before it enters the system
a. 1, 2
b. 1, 2, 3
c. 1, 2, 4
d. 2, 3, 4
e. 3, 4.
b. 1, 2, 3
An AC motor which will drop out of synchronism and simply trip when overloaded is the:
a. slip-ring induction motor
b. induction motor
c. wound rotor induction motor
d. synchronous motor
e. single phase motor.
d. synchronous motor
The purpose of a spiral or a helix Bourdon tube is to:
a. increase the pressure rating
b. provide a greater degree of rotation
c. decrease the degree of rotation
d. decrease the linear motion
e. reduce fluttering of the indicator needle
b. provide a greater degree of rotation
The operating pressure control will control the:
a. steam pressure in the boiler
b. gas pressure to the burner
c. water pressure to the boiler
D. boiler furnace pressure
e. steam pressure in the steam header
a. steam pressure in the boiler
An air atomizing compressor is usually:
a. a variable displacement type
b. a centrifugal type
c. an axial type
d. a positive displacement type
e. a regenerative type.
d. a positive displacement type
According to the ASME code, the scale on the dial of the steam gauge for a low pressure steam heating boiler shall be graduated to not less than:
a. 210 kPa
b. 420 kPa
c. 510 kPa
d. 640 kPa
e. 720 kPa
a. 210 kPa
The purpose of the small vent valve or cock on top of the shell or on top of the water column on most boilers is to allow:
a. water to escape from the boiler when the boiler is being filled with air
b. air in to the boiler when the boiler is being filled with water
c. water to escape before the steam stop valve is opened during the warm-up period
d. air to escape from the boiler when the boiler is being filled with water
e. water into the boiler when the boiler is being drained or cooled preventing the formation of a vacuum.
d. air to escape from the boiler when the boiler is being filled with water
Your boiler is operated with automatic water feeders. If the boiler suddenly requires an increase in water treatment, what should you look for:
a. Make sure the blow-off valves are open
b. See if the chemical pump has stopped
c. Check for a loss of feedwater
d. Check to see if the chemical supplier has sent the wrong chemicals
e. Nothing. Simply increase the pump stroke to put more chemicals into the system
c. Check for a loss of feedwater
The two pipe gravity return steam heating system, now obsolete, had the disadvantage that during startup, some steam could pass through a radiator without condensing and could enter other radiators via the return main, thus trapping:
a. water in the center
b. steam in the center
c. condensate in the center
d. debris in the center
e. air in the center.
e. air in the center.
One of the disadvantages of the forced warm air heating systems is the:
a. installation and maintenance costs are higher than the steam heating systems
b. air contains too much moisture
c. system can be quite noisy as compared to the gravity warm air heating systems
d. poor air circulation e. high cost for the system due to specialty equipment required.
c. system can be quite noisy as compared to the gravity warm air heating systems
Air filters used in warm air heating systems can be divided into the following groups:
a. automatic and manual
b. mechanical pneumatic
c. mechanical and electronic
d. electronic and manual
e. continuous and intermittent
c. mechanical and electronic
Which of the following is the equipment used for direct electric heating systems?
- electric boilers
- baseboard heaters
- wall heaters
- unit heaters
- warm air furnaces
a. 1, 2, 3
b. 2, 3, 4
c. 3, 4, 5
d. 1, 3, 5
e. 2, 4, 5.
b. 2, 3, 4
Which of the following is not a physical property of refrigerants
a. Toxicity
b. Odor
c. Leakage tendency
d. Density
e. Explosiveness.
d. Density
Before charging a system which of the following needs to be done?
a. Interlocks need to be tested
b. Sequence of controls need to be tested
c. Controls need to be set
d. Required valves need to be opened
e. All of the above.
e. All of the above.
Short radius elbows should be provided with what?
a. Stiffeners
b. Turning vanes
c. Miter elbows
d. Positive lock dampers
e. Flexible connections
b. Turning vanes
Steam coils with long tube lengths:
a. have the greatest freeing problems at extremely low temperatures such as -35°C
b. have the greatest freezing problems at temperatures of about –2°C to –1°C
c. have freezing problems at any temperature
d. are not likely to freeze at any temperature
e. are less likely to freeze than steam coils with short tube lengths
b. have the greatest freezing problems at temperatures of about –2°C to –1°C
Which of the following statements about cooling and de-humidification is false?
a. Air washers are used to dehumidify air
b. When air leaves the washer it will be close to 100% relative humidity
c. The spray water carries off the latent heat of condensation of the water vapor in the air.
d. Dry bulb temperatures are increased
e. Dew point temperatures are lowered.
d. Dry bulb temperatures are increased
Chalk or ______ may be used to rub on the surface of rough castings as a marking material.
a. aluminum sulphate
b. grinding compound
c. soap stone
d. blue vitriol
e. wax.
c. soap stone
A single pole scaffold:
a. should not be used
b. must be constructed of metal only
c. is partially supported by a building
d. must have supporting rigging attached to it
e. need not be plumb, only level
c. is partially supported by a building
The initial fill of a hot oil system surge tank is done by:
a. pipe line
b. use of a vacuum pump
c. field pressure
d. bucket brigade
e. bulk truck.
e. bulk truck.
The over all purposes of an oil refinery are to:
a. Only remove the crude oil contaminants such as water and hydrogen sulphide
b. Only process the crude oil into specific end products
c. Only process the crude oil into diesel fuel and gasoline
d. Remove crude oil contaminants and process the crude oil into specific end products
e. Only fractionate the raw crude oil into specific end products
d. Remove crude oil contaminants and process the crude oil into specific end products
While refractory is drying in a heater, circulated oil in the tubes is:
a. Allowed to rise in temperature at not more than 55°C per hour
b. Allowed to drop in temperature at not more than 55°C per hour
c. Maintained in temperature
d. Drained from the system
e. Superheated.
a. Allowed to rise in temperature at not more than 55°C per hour
. The contaminants in a natural gas may include:
a. hydrogen sulphide
b. pentane
c. hexane
d. methane
e. oxygen.
a. hydrogen sulphide
