Compressors

Question 1

How many stages can you have on a single rotor

Answer 1

12

Question 2

Type of casing used on small units with low-pressure ratios and small volumes

Answer 2

Sectional

Question 3

Horizontally split casings are limited to less than this psi

Answer 3

1000 psi

Question 4

Vertically split casings are used in high pressure applications of up to this psi

Answer 4

10000 psi

Question 5

Compressor shaft speeds can exceed this many rpm

Answer 5

50000 rpm

Question 6

The three basic impeller styles

Answer 6

Open, semi-closed, close

Question 7

The most common seal used in dynamic compressors

Answer 7

Labyrinth

Question 8

Seals used where there are low pressure requirements

Answer 8

Carbon ring (1/4 to 1/2 inch wide)

Question 9

Two types of bearings used

Answer 9

Plain journal - for larger multi-stage compressors

Thrust - Usually tilting pad type

Question 10

This refers to the rotor being supported by bearings at both ends

Answer 10

Beam

Question 11

Axial compressors moves large volumes of gas in excess of this

Answer 11

500 000 CFM

Question 12

Axial flow compressors are compromised of these three things

Answer 12

Rotor
Stator
Casing

Question 13

What device can you use to examine the inside of s compressor without having to remove the cover

Answer 13

Borescope

Question 14

What can you use to clean the blades while the compressor is still running

Answer 14

Crushed walnut shells

Question 15

The range of stability in compressors are represented between these two points on a graph

Answer 15

Surge point and Stonewall point

Question 16

This occurs when low flow causes flow reversal and compressed gas rushes back from the discharge to the inlet

Answer 16

Surge (causes pressure drop at the discharge)

Question 17

This is the point along the compressor curve where maximum flow has been reached

Answer 17

Stonewall

Question 18

Three ways to increase pressure in a sealed container

Answer 18

Reduce the Volume
Heat the Gas
Pack more gas into the confined space

Question 19

The most accurate means of measuring a vacuum

Answer 19

Manometer

Question 20

Most applications above 700psi use these types of compressors

Answer 20

Reciprocating

Question 21

These compressors can run without oil

Answer 21

Labyrinth

Question 22

Intercoolers reduce the average power requirements of a compressor by this much

Answer 22

15%

Question 23

Pressure ratios are limited to this

Answer 23

5:1

Question 24

Valves held together with a nut always have it facing this way

Answer 24

Away from the cylinder