Pneumatics Final

Question 1

What are the two categories of fluid power?

Answer 1

Hydraulics & pneumatics

Question 2

What are the three things that fluid does?

Answer 2

1. It flows
2. Takes the shape of its container
3. Exerts a pressure

Question 3

Difference between liquids and gases?

Answer 3

Liquids have a fixed volume, gases volume is determined by the pressure it is exposed to.

Question 4

Definition of pressure?

Answer 4

Force per unit area OR
Lbs/sq in

Question 5

3 ways pressure can be created?

Answer 5

1. Force applied to confined fluid
2. Weight of a column of fluid
3. Resistance to flow

Question 6

Definition of a vacuum?

Answer 6

Any pressure less than atmospheric

Question 7

Definition of an orfice?

Answer 7

Any restricted passage (For flow)

Question 8

The amount of flow through an orfice is determined by what 3 things?

Answer 8

1. Size of orfice
2. Viscosity of fluid
3. Pressure drop

Question 9

What slows down the cylinder at the end of its stroke?

Answer 9

Cushion valves

Question 10

What is a check valve?

Answer 10

Valve which allows flow in only 1 direction. Held by a spring (typically requires 5PSI to open)

Question 11

Pressure is measured in what?

Answer 11

PSI

Question 12

Flow rate in pneumatics is measured In what?

Answer 12

CFM

Question 13

What are the 3 types of center conditions in a 3 position DCV?

Answer 13

1. Blocked
2. Exhaust
3. Pressure

Question 14

Flow controls are in 2 major categories, what are they?

Answer 14

1. Fixed
2. Adjustable

Question 15

Give an example of fixed and adjustable flow controls.

Answer 15

Fixed - orfice plate
Adjustable - needle valve

Question 16

What does a quick exhaust valve do?

Answer 16

Increase exhaust flow in order to increase rod speed.

Question 17

Air is drawn into a fluid power motor by what?

Answer 17

The smallest volume chamber

Question 18

What is required for powered reverse motion in a fluid Power cylinder?

Answer 18

4 way dcv

Question 19

Formulas for pressure, force and area?

Answer 19

Force - P x A = F
Pressure - F/A =P
Area - F/P = A

Question 20

What device cools between multistage compression?

Answer 20

Intercooler

Question 21

Limiting flow in a fluid power system means you limit what?

Answer 21

Speed

Question 22

Limiting pressure in a fluid power system means you limit?

Answer 22

Force

Question 23

3 things that a valve controls?

Answer 23

1. System pressure
2. Direction of flow
3. Rate of flow

Question 24

What is a Regulator?

Answer 24

Pressure control valve which limits downhill pressure by stopping or limiting flow, which stops pressure from building AKA A device which limits flow to stop downhill pressure.

Question 25

What is a safety relief valve?

Answer 25

Normally non passing valve which allows flow once a certain pressure is achieved in order to prevent over pressurization.

Question 26

What do cushion valves protect against?

Answer 26

Shock and hammer

Question 27

What does FRL stand for?

Answer 27

Filter, regulator, lubricator

Question 28

Why do we use lubrication?

Answer 28

To lubricate seals, reduce friction and heat, and to extend the life of something

Question 29

How should you always meter flow to a cylinder?

Answer 29

When in doubt meter out

Question 30

Definition of a valve?

Answer 30

Mechanical device which consists of a body and a moving part which connects and disconnects within the body to connect or disconnect flow.

Question 31

Best place for a flow control?

Answer 31

As close to the cylinder as possible which still being accessible.

Question 32

What are the 3 basic forms of matter?

Answer 32

Solid, liquid, gas.

Question 33

List the three states that water can exist as.

Answer 33

Solid (ice), liquid (water), gas (steam).

Question 34

How does mass differ from weight?

Answer 34

Mass is the amount of matter in an object, while weight is the force exerted by gravity on that mass.

Question 35

What is the formula for the area of a circle?

Answer 35

A=.7854xD²

Question 36

In many places, the term “head” is used to describe _______.

Answer 36

Pressure

Question 37

What causes air to dissolve into liquid?

Answer 37

Atmospheric Pressure.

Question 38

What causes dissolved air to separate from water

Answer 38

Lack of atmospheric pressure (vacuum).

Question 39

What causes barometric pressure to rise?

Answer 39

Rise in atmospheric pressure.

Question 40

Where does fluid flow in a parallel flow path?

Answer 40

The the lowest pressure/flow path.

Question 41

A lift in a filling station has a 10in diameter piston. If the pressure required to lift a certain automobile is 50psi, how much does the automobile weight?

Answer 41

In order to solve, you use the formula F=PxA. The weight of the automobile is the force(F). The pressure of the piston(P) is 50psi. You need to find the area of the piston using the formula .7854x10² (.7854xD²). This gives you the area(A), which is 78.54. Then you plug in the number F=50x78.54 which equals 3,927lbs.

Question 42

What pressure would be required to lift a 5000lb load with a 6in diameter cylinder?

Answer 42

In order to solve, you will use the formula, P=F/A. You are solving for the pressure required to lift the load(P). The force(F) is given at 5000lbs. You solve for the area using the formula, .7854x6² (.7854xD²), which equals 28.2744. This gives you the area(A) of the cylinder. Then you plug in the numbers. P=5000/28.2744 which comes out to 176.84psi. REMEMBER!! Do not round until you have a final answer, use the ANS button on the calculator.

Question 43

If you need to lift a 60,000lb coil with a 5in diameter cylinder using 3000psi, can you lift the coil?

Answer 43

To solve this, you use the formula, F=PxA. You are solving for force(F). You have the pressure(P) of the cylinder at 3000psi. You need to solve for the area(A) of the cylinder using the formula, .7845x5² (.7854xD²) which gives you 19.635. Then you plug in the numbers. F=3000x19.635 which comes out to 58,905lbs. This means you cannot lift the coil.

Question 44

What is a pressure switch?

Answer 44

A device which controls electrical components using pressure.

Question 45

What affects actuator speed?

Answer 45

Restriction with a needle valve or a needle valve with a bypass check, often called a flow control.

Question 46

What do directional control valves control?

Answer 46

The direction of flow.

Question 47

To control speed, you must______

Answer 47

Control flow

Question 48

What is the minimum number of positions in a DCV?

Answer 48

2

Question 49

What is the minimum number of ways in a DCV?

Answer 49

2

Question 50

Which DCVs require passing or non passing information?

Answer 50

2 and 3 way DCVs

Question 51

Which DCVs do not require passing or non passing information?

Answer 51

4 way and above.

Question 52

What is the most common type of Center on a 3 position DCV?

Answer 52

Blocked Center

Question 53

What is a purpose of a 2 way DCV?

Answer 53

Gives on/off functions

Question 54

What is the purpose of a 3 way DCV?

Answer 54

Pressurize and exhaust 1 port.

Question 55

What is the purpose of a 4 way DCV?

Answer 55

Powered reverse motion.

Question 56

What are the types of DCV Actuators?

Answer 56

Manual Mechanical Electrical Pilot Pressure

Question 57

What is a detent?

Answer 57

A device that holds a DCV in a desired position

Question 58

. / . \ .____/_____. What is this DCV? | | |--| |--| |________| | | |--------->| |________| | \ |

Answer 58

2 Position 2 Way 2 Port Normally Non Passing Electrically Operated Spring Returned DCV

Question 59

What is a cylinder used for?

Answer 59

Converts fluid power energy into Straight-Line Mechanical Energy

Question 60

What is the primary purpose for all cylinder seals?

Answer 60

Allow the piston to pressurize.

Question 61

What is the Primary seal used for?

Answer 61

Keeps the fluid from rushing out of the cylinder around the rod.

Question 62

What is the wiper seal for?

Answer 62

Clean and lubricate the rod.

Question 63

What is the end of the cylinder opposite of the rod?

Answer 63

Blind end.

Question 64

What is the end called on the cylinder on the side of the rod?

Answer 64

Rod end.

Question 65

What is the load called when the rod extends?

Answer 65

Thrust Load.

Question 66

What damage can occur when the cylinder rod extends?

Answer 66

Rod buckle.

Question 67

What damage can occur when the cylinder rod retracts? (Tension Load)

Answer 67

Ripped threads

Question 68

What are the 4 methods of cylinder mounting?

Answer 68

Cap Fixed Clevis Head Trunnion Cap Square Flange Side Lugs

Question 69

Which cylinder has 1 threaded rod and moves in 1 direction?

Answer 69

Single Acting

Question 70

Which cylinder uses alternating pressure to move the piston both directions?

Answer 70

Double Acting

Question 71

Which cylinder has 2 separate rods which move both directions.

Answer 71

Double acting double rod

Question 72

What do pneumatic motors do?

Answer 72

Convert potential energy of compressed air into Rotary Mechanical Energy.

Question 73

What are the 2 basic hydrostatic motors?

Answer 73

Piston and Vane

Question 74

On a motor, what does an empty energy triangle denote?

Answer 74

Pneumatic (Air)

Question 75

On a motor, what does 1 energy triangle denote?

Answer 75

1 directional motor

Question 76

On a motor, what do 2 energy triangle denote?

Answer 76

Bidirectional motor (2 directions)

Question 77

What is a Ram Cylinder

Answer 77

Cylinder in which the movable element is the piston rod. An example is a Porta Power Jack.