3rd 6 Flashcards
(209 cards)
In a pneumatic system what provides the force that performs work?
compressed Air
How much work is done by a piston that exerts a force of 15lbs through a distance of 10in?
150 in-lbs
Heating a gas in a solid rigid container will ____ the ____ of the gas.
increase; pressure
Two cylinders having different diameters are connected by an air line. A force is applied to the smaller piston. The larger piston exerts a force on a load and moves it. The force on the load is ____ the force applied to the small piston, and the distance load moves is ____ the distance the small piston moves.
greater than; less than
When air flowing in a pipe reaches a section where the diameter is reduced, the speed of the air ____ and its pressure ____.
increases; decreases
A reciprocating compressor is one kind of ____ compressor
positive- displacement
In a typical reciprocating compressor, the intake valves are forced open by:
atmospheric pressure
The purpose of the intercooler between the two stages of a two stage compressor is to reduce the ____
power needed to run
The purpose of lubricating oil in a compressor is to reduce friction between the moving parts and:
improve the cooling of compressor
The advantage of unloading a compressor is to allow it to
Run without delivering air
Single-stage sliding- vane compressors can produce pressures up to
50 psi
Rotary screw compressors run at speeds ranging from ____ to ____ rpm
3,000 ; 12,000
Impeller compressors deliver air at ____ volume and ____ pressure
high; low
Compared to other compressors, centrifugal compressors
more power
Most effective way to reduce output of a centrifugal compressor is ____, but may not work if the reduction is too ____
speed variation; large
Water often collects in pneumatic systems because when air is compressed its ____ decreases
moisture capacity
Most common way to remove water vapor from the air leaving a compressor is to:
cool the air
Water cooled after coolers are typically used with ____ capacity compressors that run ____ hours a day
large; 10 or more
A desiccant removes water from air by ____ it.
absorbing
The main purpose of a receiver in a pneumatic system
maintain pressure during peak demand
The operation of an internal separator depends on
rapid change in the direction of air flow
Of the particles listed, the smallest are the ____ particles
aerosol
A filter can stop 100% of the particles down to a specific min size. Known as the filter’s ____ rating
absolute
An advantage of wetted filters over dry
can be cleaned many times