Schematics And Symbols

Question 1

A schamatic helps you understand what is happening in a system through

Answer 1

symbols and lines

Question 2

In a DC circuit the electrons flow from

Answer 2

Negative to positive and steadily in one direction

Question 3

The direction of fluid flow in a piping diagram is indicated…..

Answer 3

By arrows

Question 4

More than one arrangement (reverse or alternate flow) of flow within a piping system is often indicated in a…..

Answer 4

Separate smaller diagram called a supplementary diagram

Question 5

What is a cutaway diagram?

Answer 5

It is a double line drawing showing a system with some internal detail.

Question 6

If the title of a schematic does not specify the type of system it represents you should….

Answer 6

Look for other clues such as
• title
•legend- info on lines and symbols
•parts list and the parts used for them

Question 7

What can help make a drawing clearer or easier to understand?

Answer 7

Notes by the engineer or technician who prepared the drawing

Question 8

What does a line of short dashes represent on a schematic?

Answer 8

Fluid power diagram - drain line

Electrical diagram - exposed wiring
Piping diagram - vent line

Question 9

General electrical symbols

Answer 9

A

Question 10

Do you wiring diagrams how the parts are connected internally or externally?

Answer 10

Externally

Question 11

How do you control and adjust flow in a piping system

Answer 11

They are controlled with valves.

Question 12

An elbow in a piping system usually changes what?

Answer 12

It changes the direction of flow.

Question 13

What does a reducer do in a piping system?

Answer 13

Connects two pipes of different diameter.

Question 14

What designates a flanged fitting when looking at symbols.

Answer 14

two small interjecting lines at the openings indicate a flanged fitting/pipe

Question 15

A circuit in which total circuit current flow from one load to the next.

Answer 15

A series circuit.

Question 16

In a circuit, each load can be turned on and off independently of each other.

Answer 16

A parallel circuit.

Question 17

Which valve is best for quickly starting and stopping flow?

Answer 17

A plug or cock valve.

Question 18

When should check valves be used?

Answer 18

To ensure fluid flows in only one direction.

Question 19

What is the symbol for a glove valve.

Answer 19

A bowtie symbol.

Question 20

Sometimes measurements or sizes are on the symbol, other times they are in a side note. what is the last number in the size?

Answer 20

It is the branch line size.

Question 21

How many different kinds of fluid power systems are there?

Answer 21

There are 2.
Hydraulic system handles liquids.
Pneumatic system handles air or gases.

Question 22

What are the basic elements of a fluid power system?

Answer 22

reservoir- stores fluid 
pump- provides flow and pressure
actuator-reacts to pressure and does work 
valves-direct and adjust flow
piping-connect parts of the system

Question 23

What is the symbol for a sealed or pressurized pneumatic receiver.

Answer 23

looks like an empty pill

Question 24

Symbols describe many parts of the system to us such as….

Answer 24

It shows connections, flow paths, and function.

It does not show physical arrangement.

Question 25

What does the symbol for an electric motor look like?

Answer 25

circle with an M inside, with an arrow around the outside.

Question 26

What does the valve assembly do in a master cylinder power braking system?

Answer 26

directs the flow of brake fluid.

Question 27

Describe a closed fluid power system.

Answer 27

It indicates the fluid is drawn out the reservoir, used, then returned. The same fluid is used over and over again.

Question 28

Sometimes, sections of a hydraulic or pneumatic system are outlines by phantom lines (dash followed by two small dashes) what are these areas called?

Answer 28

They are called local areas.

Question 29

One of the main components of a refrigeration subsystem is the….

Answer 29

The evaporator or air cooling coil or liquid chiller.

Question 30

What is an example of a direct control (directly attached) component in a refrigeration system?

Answer 30

A thermostatic expansion valve. It controls the flow of refrigerant to the evaporator

Question 31

Describe a direct control ADR valve.

Answer 31

It opens if the pressure of the refrigerant drops on the outlet side of the evaporator.

Question 32

Describe a transistor.

Answer 32

A transistor can amplify and switch electrical signals much like a valve.

Question 33

Dashed lines on a refrigeration electrical control diagram indicate what?

Answer 33

Field / Site installed

Question 34

Describe fusion.

Answer 34

The joining of two materials by melting them together.

Question 35

Describe resistance welding.

Answer 35

It is the squeeze and heat process. Materials is held together while the electric current passes through, melting the material for moment and fusing them.

Question 36

What is the symbol for a V weld.

Answer 36

It is the actual symbol V.

Question 37

How are welds that must be completed in the field on a welding schematic.

Answer 37

They are indicated by a flag at the bend of the arrow.

Question 38

If dimensions or information are not shown at the symbol what should you look for information.

Answer 38

Look for the legend, it will describe special dimensions.