Millwright Level 3 Pneumatics Mechanics
Practice Exams
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1. How does a regulator in a pneumatic system respond to a decrease of
downstream air pressure?: increases orfice size to increase air flow
2. Which type of directional control valve is an on-off valve in a pneumatic
system?: two-way valve
3. Where should the air intake be located?: in the coolest place possible
4. what is an air receivers purpose?: to compensate for fluctuations in demand,
and to dampen pulsations.
5. what things must every air receiver have?: Gauge, drain, and pressure relief
valve
6. what must the pressure relief valve be set at?: must be no higher then the
lowest maximum pressure rating of any part in the system.
7. how should safety relief valves be mounted, and why?: vertically, usually on
top, to prevent dirt and sludge from blocking them.
8. what are the three types of commonly used pipe systems?: the grid(dead
end) system, decentralized system(unit system) and Loop system
9. what is the preferred or recommended piping system?: the loop system
10. Describe the Grid(dead end) system of piping.: its the simplest, only requires
one compressor, starts with a large diameter supply line that gradually decreases.
one drawback is that systems at the end of the circuit could face air starvation when
upstream demand is heavy.
11. Describe the decentralized system: composed of two or more compressors
each with their own grid. grids may or may not be interconnected. advantage is each
compressor is close to its point of use which means there is less pressure drop and
more uniform supply pressure.
12. Describe the loop system of piping?: Two or more compressors feed into the
