TPC 309 Basic Pneumatics Flashcards
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 15lb through a distance of 10in?
150 in-lb
Heating a gas in a sealed, rigid container will ______ the ________ of the gas
Increase; pressure
Two cylinders having different diameters are connected by an air line. A force applied to the smaller piston makes it move. In response, the larger piston exerts a force on a load and makes it move. The force on the load is ______ the force applied to the smaller piston, and the distance the load moves is ______ the distance the smaller 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 the….
Atmospheric pressure
The purpose of an intercooler between the stages of a two-stage compresor is to reduce the:
Power needed to run the compressor
The purposes of lubricating oil in a compressor are to reduce friction between the moving parts and to…
Improve the cooling of the 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 ______ psi
50
Rotary screw compressors run at speeds ranging from ______ to ________ rpm.
3000; 12000
Impeller compressors deliver air at _____ volume and ______ pressure.
High; low
Compared to other kinds of compressors, centrifugal compressors…
Require more power
The most effective method of reducing the output of centrifugal compressors is ______ but may not work well if the reduction is too _____
Speed variation; large
Water often collects in a pneumatic system, because when air is compressed it’s _______ decreases.
Moisture capacity
The 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; ten or more
A dessicant removes water from air by ______ it.
Absorbing
The main purpose of the receiver in a pneumatic system is to…
Maintain pressure during peak demand
The operation of an inertial separator depends on a(n)
rapid change in the direction of air flow
Of the particles listed below, the smallest are the _____ particles.
Aerosol
A filter can stop 100 percent of the particles down to a specifed minimum size. This size is called the filter’s ______ rating.
Absolute
An advantage of wetted filters over dry filters is that wetted filters :
Can be cleaned many times
A fine mist lubricator should be use in a pneumatic system if the air flow is ______ and/or the distance to the equipment is ______.
Intermittent; long
Laminar air flow in a piping system is made turbulent by
Constructions in the pipe
Greater pressure losses occur in a pneumatics system if there air is at ______ pressure, because of greater ______.
Low; friction
When used as a compressor discharge line, a pipe run should slope _______ in the direction of the airflow by 1in for every _____ ft of pipe.
Downward; 10
When should you use pipe joint compound in connecting NPT-threaded pipe?
Always
If an air hose is not completely depressurized when you disconnect it, the greatest danger to you is a sudden…
Blowing of dust or chips
A four-way valve has four:
Connections ports
The_______ valve is a good throttling device and is suitable for high-pressure service. It causes _____ pressure loss in the line.
Needle; high
The spool in a valve controls the flow of air by ______ from one position to another. In a high-pressure system, the spool is ____ to move.
Sliding; easy
An advantage of four-way valves over two and three way valves is that they
Simplify the controls
A valve has five connecting ports, two of which are exhaust ports. This valve is a _____ valve.
Four-way
The cracking pressure or a poppet-type relief valve is determined by the
Spring adjustment
A diaphragm-type relief valve responds very quickly to a pressure change because of is
Large pressure-sensitive area
The only purpose of a pressure relief valve is to:
Protect the system from damage
An increase in pressure on the secondary side of a pressure regulating valve _______ the valve.
Slightly closes
The best way to guard against excessive pressure on the secondary side of a pressure regulator is to
Use a regulator with a built-in relief valve
The thrust that can be allied when the rod of a single-rod, double-acting pneumatic cylinder is moving out of the cylinder is_____ the thrust that can be applied when the rod is moving into the cylinder.
Greater than
An internal spring is sometimes used in return the piston in a ______-acting ______- rod pneumatic cylinder.
Single; single
The main purpose of an exhaust-flow control metering valve on a pneumatic cylinder is to….
limit the return-stroke speed
A cylinder that must be free to pivot requires a(n) _____ mounting.
Trunnion or clevis
You can determine whether a control valve can deliver air rapidly enough for a cylinder by calculating the ______ required by the valve.
Capacity coefficient
The highest torque a pneumatic motor can exert on a load is it’s ______ torque.
Stalling
The horsepower of a pneumatic motor varies with the _____ and the _____ of the motor shaft.
Speed; torque
The highest power ouput of a pneumatic motor occurs when its speed is
Medium
An axial-piston pneumatic motor transmits force from the piston to the output shaft by means of a:
Cam plate and gears
Air pressure of 100 psi can create hydraulic pressure of 1000 psi if an air piston drives a ______hydraulic piston(s)
Smaller-diameter
