Module 5 Flashcards
The minimum pressure at which a component begins to split apart
Bursting presssure
Bursting pressure divided by system operation pressure
Safety factor
Air at normal atmospheric pressure (14.7 psi)
Free air
Piping fixture used to trap and eliminate water in the line
Drain leg
Measurement of a curve in tubing, from tubing centerline to the center of the circle
Bend radius
Name the three types of compressed-air conductors used in a pneumatic piping system.
Pipe
Tubing
Hose
Air should flow through a pipe in a(n) _____ pattern.
Streamlined or Laminar
The size of an air line should be selected so only a small _____ drop occurs.
Pressure
Name at least four items that affect pressure drop.
Volume of air Air pressure Length of pipe Number of fittings Number of bends
To reduce the distance air travels in a large loop system, _____ air receivers are used.
Auxiliary or Extra
The lower the pressure in a pipe, the _____ the pressure losses will be.
Larger
Pressure losses through fittings and valves are given in terms of _____ of straight pipe.
Feet (or Lengths)
Name the three methods used for connecting pipe in a pneumatic system.
Threading
Welding
Flanging
Compressor discharge lines should slope away from the compressor at a rate of ______ in. for every _____ ft.
1, 10
NPT, when used for pneumatic systems, seals against air leaks with flank-to-flank contact and _____.
Piping compound
When connecting pipes, you must never apply piping compound to the _____.
Thread ends
More accurate inside and outside diameters are an advantage of _____.
Metallic tubing
Avoid using metallic tubing that has been bent and then _____.
Straightened
When an air hose is connected to pneumatic piping, the hose should be one size _____ than the size of the connecting pipe thread.
Larger
Hose fittings may be classed as permanent and _____.
Reusable
The type of hose coupling that uses a spring-loaded poppet to seal off the outlet when the hose is removed is called a(n) _____ coupling.
Quick-disconnect
Turbulent airflow is likely to result from a(n) _____.
Large airflow velocity increase.
Which type of threaded fitting is probably the best suited to all but heavy-duty air-line applications?
150 lb malleable iron.
The pressure drop between the air receiver and the farthest point of air use should be no more than _____ % of the compressor cutout pressure.
10
The rate of downward slope for compressed-air piping used for compressor distribution lines should be _____.
1 in. per 10 ft.
Excessive pressure drops occurring in a loop system during peak flow may be avoided by the use of auxiliary _____.
Air receivers and compressors.
Long pipe runs should always be _____.
Supported with hangers.
How does a change in air pressure in a pipe affect the pressure losses?
Decreased pressure, higher losses.
Most nonmetallic tubing can be used for a maximum of _____.
100 psi and 190F
The pressure loss through fittings and valves is calculated in terms of _____.
Feet of straight pipe.
When disconnecting an air hose, make sure to take all of the following precautions except
a. depressurize the hose
b. have a buddy present
c. use the shutoff valve, if there is one
d. wear eye protection
b. Have a buddy present.
