Chapter 7 Flashcards
As volume decreases, pressure…
Increases
If the volume of a given gas is reduced one half by compression at constant temp, its density and absolute pressure will be…
Doubled
Absolute pressure equals…
Gage pressure plus 14.7 psi
Quantity and pressure of the discharged air with a centrifugal fan depends on what
Size, speed, and air density
In an unbalanced machine rotor situation as the speed increases…
The center of gravity is moved further from the axis increasing the unbalanced or whipping action
Some of the common causes of high temperatures in air compressor systems are
Lack of cooling water, recompression due to valve failure, and dirty or fouled coolers due to over lube
Large air compressors are generally unloaded while starting and stopping, why
To reduce the starting torque and permit more gradual stopping
On air compressors, high outlet air temperatures indicate what
High inlet air temperatures, faulty valves and recompression, fouled cooling surfaces and insufficient cooling water
When air is saturated with water vapor, water droplets form, this condensation point is known as the…
Dew point
They dampen the pulsations or pressure waves in the air system, they also act as reservoirs for storing air, they act as separators to remove sludge, and they reduce pressure drops
Air receivers
In general blank are used to measure vacuums and low pressures
Manometers
What is used to measure pressures close to zero gage pressure
Diaphragm Gages
What is used to measure high or wide pressure ranges
Bourdon type gages
