1 Teepeesee Flashcards
In a pneumatic system what provides force that performs work?
Compressed air
How much work is done by a piston that exerts a force if 15lbs through a distance of 10in?
150 in-lbs
Work = force x piston travel
Work = 15 x 10 = 150
Heating a gas in a scaled 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 it’s 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 2-stage compressor is to reduce the:
The power needed to run the compressor
The purposes of lubricating oil in a compressor are to reduce friction between moving parts and to:
Improve 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 to 12000
Impeller compressors deliver air at ______ volume and ______ pressure.
High; low
Compared to other kinds of compressors, centrifugal compressors:
Require more power
The most efficient 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 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; more than 10
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
Aerosols
A filter can stop 100% of particles down to a specific size. The 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 used in a pneumatic system if the air flow is __________ and/or the distance to the equipment is ________.
Intermittent; long
Laminar airflow in a piping system is made turbulent by:
Constrictions in the pipe
Greater pressure losses occur in a pneumatic system if the air is at _____ pressure because of greater____________.
Low; high friction
When used as a compressor discharge line, a pipe run should slope _______ in the direction of the airflow by 1 in for every ____ft of pipe
Downwards; 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:
Connecting 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 2 or 3 way valves is that they:
Simplify the controls
A valve has 5 connecting parts, two of which are exhaust ports. This valve is a _______ valve
Four-way
The cracking pressure of a simple poppet-type relief valve is determined by the:
Spring adjustment
A diaphragm-type relief valve responds very quickly to a pressure change because of its:
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 applied 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 to return the piston in a _______-acting, ________-rod pneumatic system.
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 its _________ torque.
Stalling
The horsepower of a pneumatic motor varies with the ________ and the _______ of the motor shaft.
Speed; torque
The highest power output of a pneumatic motor occurs when it’s speed is:
Medium
The axial-position 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
