Hydraulic Fundamentals

Question 1

Working conductors carry ____ pump flow rate.

Answer 1

Full

Question 2

Flexible hose is depicted graphically with an ____ line.

Answer 2

Arced

Question 3

Pilot lines are ____-sensing lines that carry pressurized oil to operate system components.

Answer 3

Pressure

Question 4

____ lines carry internal leakage oil from certain hydraulic components back to the reservoir.

Answer 4

Drain

Question 5

Hydraulic motors convert ____ energy into rotational mechanical energy.

Answer 5

Hydraulic

Question 6

Hydraulic cylinders that can be hydraulically actuated in one direction only are ____ cylinders.

Answer 6

Single-acting

Question 7

Hydraulic cylinders that can be actuated in two directions are ____ cylinders.

Answer 7

Double-acting

Question 8

Three major types of hydraulic valves are:

Answer 8

Pressure control valves
Flow control valves
Directional control vavles

Question 9

An orifice is a ____ to oil flow.

Answer 9

Restriction

Question 10

Filters remove ____ from hydraulic oil.

Answer 10

Contamination

Question 11

Coolers remove ____ energy from the hydraulic oil.

Answer 11

Heat

Question 12

Heat exchangers add ____ energy to the hydraulic oil.

Answer 12

Heat

Question 13

Accumulators are installed in a hydraulic system to store ____ energy or to absorb ____.

Answer 13

Hydraulic

Shock

Question 14

Avoid working in ____ points.

Answer 14

Pinch

Question 15

Do not cut, heat, weld, solder or use a torch near ____ hydraulic lines.

Answer 15

Pressurized

Question 16

An ________ is a device that converts hydraulic power into mechanical power.

Answer 16

Actuator.

Ex. Hydraulic motors, Cylinders.

Question 17

____ ____ describes the volume of a fluid passing a given point in a given period of time.

Answer 17

Flow Rate.
Imperial system: Gallons Per Minute (GPM)
Metric system: Litres Per Minute (L/min)

Question 18

The term ____ refers to any substance that flows.

Answer 18

Fluid.

Liquids & Gases are both fluids.

Question 19

____ is described as a push or pull.

Answer 19

Force.
Imperial system: Pound (lb)
Metric system: Newton (N)

Question 20

__________ is the science that pertains to the transmission of force and/or motion through a fluid.

Answer 20

Hydraulics

Question 21

____________ is the area of hydraulics that pertains to the transmission of force and/or motion using liquid motion.

Answer 21

Hydrodynamics

Ex. Waterwheels, Hydroelectric Turbines, Etc.

Question 22

_____________ is the area of hydraulics that pertains to the transmission of force and/or motion using confined liquids.

Answer 22

Hydrostatics

Ex. Hydraulic Jacks, Power Steering, Etc.

Question 23

____ is the amount of material in an object.

Answer 23

Mass

Question 24

An _______ is a device used to provide a restriction to liquid flow. It creates a pressure drop.

Answer 24

Orifice

Question 25

_______ is the amount of work done in a given period of time.

Answer 25

Power Imperial: Horsepower (hp) Metric: Watt (W)

Question 26

_______ is defined as a force per unit area. This is caused by a resistance to liquid flow and is responsible for generating force.

Answer 26

Pressure Imperial: pound per square inch (psi) Metric: Newton per meter squared (Nm2, pascal)

Question 27

A ____ is a device that converts mechanical power into hydraulic power.

Answer 27

Pump

Question 28

______ is the absence of pressure.

Answer 28

Vacuum

Question 29

_________ describes the rate of motion (speed).

Answer 29

Velocity Imperial: feet per second (ft/sec) Metric: meters per second (m/sec)

Question 30

_________ is the internal capacity of space or chamber.

Answer 30

Volume

Question 31

____ is the product of force acting through a distance.

Answer 31

Work

Question 32

_____ are compressible and _______ resist compression.

Answer 32

Gases | Liquids

Question 33

Pressure applied to a confined liquid is transmitted equally and undiminished in all directions at right angles to all surfaces.

Answer 33

Pascal's Law.

Question 34

The resistance to flow in a hydraulic system comes from which two sources?

Answer 34

Pressure Loss | The Load

Question 35

________ ____ is the pressure that is created by the resistance of system components.

Answer 35

Pressure Loss

Question 36

Pressure losses + Pressure required to overcome the load =

Answer 36

Total Pressure

Question 37

If the force applied to a surface area is doubled the pressure will:

Answer 37

Double

Question 38

If the surface area doubles and the applied force does not change the pressure will

Answer 38

be reduced by half.

Question 39

Double-acting Cylinders are used because they are able to:

Answer 39

Hydraulically extend and retract.

Question 40

Series Hydraulic Circuits offer ___ path for oil to flow.

Answer 40

one

Question 41

Parallel Hydraulic Circuits offer _______ path for oil to flow.

Answer 41

more than one

Question 42

The pressure created by the weight of a fluid is known as ____ ________.

Answer 42

Head Pressure

Question 43

Pressure that exists below atmospheric (14.7psi, 101.34kPa) is referred to as:

Answer 43

vacuum partial vacuum sub-atmospheric pressure

Question 44

The most common tool used to measure pressure is:

Answer 44

The Bourdon Tube Pressure Gauge

Question 45

While Gauge Pressure (Psig) measurements ignore atmospheric pressure, ________ ________ measurements include it.

Answer 45

Absolute Pressure (Psia)