Compressors

Question 0

A double acting piston is connected directly to the connecting rod? True or false?

Answer 0

False it is connected to the CrossHead

Question 1

The purpose of a crosshead is to keep the………… Centred in the packing throughout the full stroke

Answer 1

Piston rod

Question 2

What causes reciprocating compressor valves to open?

Answer 2

The pressure differential

Question 3

Intercoolers are used on double…………. Compresses to cool the air

Answer 3

Stage

Question 4

List the three components that the Alberta boilers safety association requires to be installed on every air receiver?

Answer 4

Safety relief valve
Pressure gage
Drain

Question 5

If there is any possibility of a blockage in a compressed air system what must be installed on the pressure side

Answer 5

The safety relief valve

Question 6

Compressor capacity is usually determined by the amount of gas that enters the suction inlet in a given period of time?
True or false?

Answer 6

True

Question 7

A two-stage compressor must compress the gas on both sides of the piston?
True or false

Answer 7

False it can be single acting

Question 8

Double acting compresses compress the gas on both sides of the piston? True or false?

Answer 8

True

Question 9

0° Kelvin is equal to 273°C?

True or false

Answer 9

True

Question 10

Atmospheric pressure at sea level is equal to how many of each of the following?
Bar?
Psi?
Kpa?

Answer 10

Bar=1
Psi=14.7
kPa=101.4

Question 11

You calculate gauge pressured by adding 14.7 to an absolute scale reading?
True or false

Answer 11

False, You subtract 14.7psi

Question 12

Compressed air operates in much the same manner as well in a hydraulic system except for two major differences, what are these two differences?

Answer 12

Gases are compressible

Gases expand to fill any container

Question 13

List the three ways air pressure can be increased?

Answer 13

Heat it
Reduce the volume
Add more gas into a confined space

Question 14

Define pascal’s law

Answer 14

Pressure in a confined static fluid acts equally and in all directions at right angle of 90°

Question 15

When pressure is increased in an enclosed space, The Temperature:

Answer 15

Increases

Question 16

If the flow rate is Constant and the velocity is decreased, there will be a………. In pressure.

Answer 16

Increase

Question 17

With an increase in altitude, hey compressor needs………….. Power to drive the compressor.

Answer 17

Less

Question 18

The combined gas law demonstrates the relationship between three variables before and after compression. State the formula that shows the relationship.

Answer 18

P1xV1/T1=P2xV2/T2

Question 19

Which compressor has the power pistons and the compression pistons sharing the same crankshaft?

Answer 19

The integral

Question 20

List the two reciprocating compressors are particularly suited to oil free delivery.

Answer 20

Labyrinth and diaphram

Question 21

Positive displacement compresses work on the principle of trapping a specific volume of air and then reducing that volume to get a higher pressure? True or false?

Answer 21

True

Question 22

How do you compresses move gases work?

Answer 22

They raise the gas pressure

Question 23

What is displacement?

Answer 23

Displacement is the total volume of air actually moved out of the compression cylinder in a given unit of time.

Question 24

What is pressure ratio

Answer 24

Pressure ratio is a ratio of the absolute discharge pressure compared to the absolute intake pressure.

Question 25

What is Volumetric efficiency?

Answer 25

Volumetric efficiency is a ratio of the actual compressor capacity compared to the calculated displacement and is expressed as a percentage

Question 26

What is swept volume

Answer 26

Swept volume refers to the volume of air that is swept or pushed out of the cylinder on the compression stroke

Question 27

What is clearance volume?

Answer 27

Clearance volume refers to the space between the piston and the cylinder head when the piston is at top dead center.

Question 28

Standard cubic foot

Answer 28

Hey standard foot of gas is the amount of gas that fills one cubic foot volume exactly at standard conditions

Question 29

What is staging

Answer 29

Single stage compression refers to those compresses in which compression from initial to final pressure is completed in one single step or stage.

Question 30

What is a single acting compressor

Answer 30

Compression occurs on only one side of the piston, or compression occurs on only one stroke for every revolution of the crank shaft.

Question 31

What is a double acting compressor

Answer 31

Compression stroke occurs on each stroke of the piston (on both sides) or compression occurs on two strokes for every revolution of the crankshaft

Question 32

What is venting

Answer 32

Before work on a compressed air system the pressure inside must be vented.

Question 33

What is a clearance pocket

Answer 33

Clearance pocket increases the clearance volume to reduce the compresses efficiency.

Question 34

What is Rod loading?

Answer 34

Rod loading refers to the sum of the suction and discharge pressures acting on both sides of a double acting compress piston

Question 35

What is Rod reversal

Answer 35

Rod reversal is a reciprocating compressor term that has to do with the alternate compression and tension forces of the piston rod during operation