Sample Exam Questions Flashcards
How do you increase pressure?
Decrease the volume
What is the best vacuum pump?
Rotary vane multi-stage
What is the most cost efficient compressor?
two stage, double acting
What are 4 ways of maximizing pressure control?
- Unloading devices (fingers)
- Throttling the air intake
- Using a variable speed drive
- Using a pressure switch
How do you decrease air slip?
Increase RPM of rotors
Where is a water trap placed?
Anywhere the air is cooled below the dew point
Where do you put after coolers?
After it leaves the compressor and before it enters the receiver
What should you do before disassembly?
ensure that timing gears have matching mate marks beforehand
What is the function of intercoolers?
Used to cool the air between stages
What are after coolers for?
Heat exchangers which cool the air after it leaves the compressor and before it enters the receiver
What are the four types of air dryers?
- Deliquescent
- Regenerative desiccant
- Refrigeration
- Membrane
What are the two types of lubricators?
- fog lubricators (short dis)
- Mist lubricators (long dis)
Pressure is controlled in the compressor by __________
unloading
Pneumatic DCVs can be either rotary or _____types
spool
Pneumatic compressors are used to compress atmospheric air reducing its ________ and increasing its ______________
Pneumatic compressors are used to compress atmospheric air reducing its volume and increasing its pressure
What is the measurement of a perfect vacuum?
0 bar or 0 psiA
Which direction dos air flow?
From high to low pressure areas
What is Boyle’s Law?
At constant temperature, absolute pressure (P) varies inversely to the volume (V)
What is Charles’s Law?
At a constant volume, a gas varies proportionately to its absolute temperature (T)
What is the ideal gas law?
P1xV1/T1 = P2xV2/T2
The best pump is ___________
rotary vane (multi-stage)
The worst pump is __________
centifugal (regenerative peripheral)
What are the two classifications of compressors?
Dynamic and positive displacment
__________________ DCV’s permit very little control as they are either wide open or off.
solenoid controlled
When a cylinder is required to return rapidly, a _____________ is installed in the retract line of the cyliner
quick exhaust valve
What are the 3 most common systems?
- Grid
- Decentralized
- Loop
How do permanent pneumatic lines deal with moisture?
They are installed in such a way that any moisture accumulating in the line flows toward a drain
What are 4 ways of controlling maximum-pressure?
- Unloading devices
- Throttling the air intake
- Using variable speed drive
- using a pressure switch to start or stop
