Unit D: Compressed Air Self Test Questions Flashcards
What is the standardized pressure for the SCFM (standard cubic feet per min) performance indicator used in the compressed air industry?
SCFM is standardized using 14.7 psi (103 kPag)
What best describes the piston configuration in a multi-stage air compressor?
Different sizes / assembled in series
What type of air compressor uses both sides of the piston to compress the air?
Double acting
Within a two-stage air compressor, what device is used to cool the air as the air moves from the first stage to the second stage?
Intercooler
What type of compressor develops pressure through the oscillations of a flexible disk?
Reciprocating diaphragm
What type of compressor is used when contamination is not allowed in the discharge air stream?
Reciprocating diaphragm
What type of compressor uses two spinning rotors to trap and compress the air?
Rotary helical screw
What type of compressor uses two spiral elements to trap / compress the air?
Rotary scroll
Which filter installed as part of a compressed air system is considered the most important?
Intake air filter
Where would a water separator be installed in relation to the aftercooler in a compressed air system?
Downstream of the aftercooler
Where would an aftercooler be installed in relation to the compressor in a compressed air system?
Downstream of the compressor
What two methods are used to reject the heat absorbed by the aftercooler?
Air cooling and water cooling
What effect does an intercooler have on compressor performance?
It improves compressor efficiency
What is the disadvantage of an undersized receiver tank?
It causes excessive compressor cycling
What is the disadvantage of an oversized receiver tank?
It wastes energy because the compressor has to run longer
What material absorbs the water vapour from the compressed air inside a deliquescent air dryer?
Salt tablets
Why is a double - wall heat exchanger used when recovering heat used for domestic water heating from an air compressor?
It provides additional protection from contamination
A straight line piping configuration has limitations when providing proper downstream pressure and flow rates. When considering equipment locations, what strategy will minimize these shortcomings?
Place the equipment with high flow requirements near the compressor
What compressor should be considered to provide optimal performance?
Closed - looped networks
What network provides the worst performance?
Octopus networks
What is the name given to a moisture drain trap used in industry that eliminates the loss of system air during the draining process?
Zero - loss drains
What are the 3 main technologies that manufacturers of compressed air drains use in their product lines?
1) pneumatic - mechanical drains
2) Electronic demand drains
3) Series timed electronic drains
What damage could result if an FRL is installed backwards?
The oil from the lubricator could cause other components to plug / become inoperable