Gas Technician III
Learning Package
Module 2 – Fasteners, Hand &
Power Tools
Contents
Learning Outcomes: ......................................................................................................................... 3
Screws: ............................................................................................................................................. 4
Nuts, Bolts & Washers: .................................................................................................................... 6
Anchors & Shields ............................................................................................................................ 7
Electrical Connectors: ...................................................................................................................... 9
Tool Safety: .................................................................................................................................... 10
Portable Power Tools ..................................................................................................................... 12
Wrenches ....................................................................................................................................... 13
Aviation Snips:................................................................................................................................ 15
Pliers:.............................................................................................................................................. 16
Screwdrivers: ................................................................................................................................. 18
Common Hand Tools...................................................................................................................... 20
Power Tools ................................................................................................................................... 21
Measurement: ............................................................................................................................... 23
Measurement Tools ....................................................................................................................... 27
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 Tools make our work easier and safer. All tools,
Learning
Outcomes:
fasteners, and measurement devices are designed with a
specific purpose in mind. In our trade, we must be able
to identify and understand the purpose of many different
types of tools.
This module focuses on common fasteners, hand, and
power tools. In later modules we will look at specialized
tools used for gas piping and electrical measurement.
After completion of this module you will be able to:
Recognize types of fasteners and understand their application to specific materials.
Identify types of common hand tools.
Identify types of power tools.
List rules for safe handling, storage, maintenance, and use of tools.
Determine measurement such as length, diameter, volume, and circumference.
Identify types of electrical wire connectors.
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 Screws are designed for specific applications and it is
Screws:
important to use the right type to prevent unfastening.
Screws are made from numerous materials including
stainless steel, aluminum, bronze, and zinc-plated steel.
Wood screws are tapered to help
draw the wood pieces together as the
Figure 2-2 Wood Screw
screw is inserted. When determining
screw length, ensure that two-thirds of the screw will
Figure 2-1 Various Screws
enter the second piece of wood.
Sheet metal screws are used to fasten two pieces of metal together.
Sheet metal screws are threaded completely from the pointed tip to the
Figure 2-3 Sheet
Metal Screw
head; the threads are sharper than those of wood screws.
Machine screws are inserted into tapped or pre-threaded holes.
Machine screws are generally used for joining metal parts.
Figure 2-4
Machine Screw
Lag screws, or lag bolts, can be used with lag shields to provide
dependable fastening in concrete and brick. The screw length
can be determined by adding the length of
Figure 2-6 Lag Screw
the lag shield, the thickness of material to
Figure 2-5 Lead Lag Shield
be fastened, plus 1/4" (6mm). The tip of the lag screw must protrude out from the
bottom of the anchor to ensure proper expansion.
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Concrete screws provide secure anchoring in concrete. They are a hardened screw with
widely spaced threads that screw directly into a pre-drilled hole. A
Figure 2-7 Concrete Screw
special carbide drill bit is used to drill the hole in the concrete.
Anchors and plugs are not necessary when using concrete screws.
Figure 2-8 Carbide Bit for
Concrete
Screw heads can be flat, oval, or round.
Flat heads are usually countersunk or rest flush with the surface.
Oval heads permit countersinking, but the head protrudes somewhat.
Round-headed screws rest on top of the material and are easiest to remove.
Rust-resistant screws, lock washers, insulating, or vibration absorbing material
should be considered where screws are exposed to conditions such as moisture,
vibration, or corrosion.
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 Bolts go through holes in material that will be
attached together. They require a nut that is turned onto
Nuts, Bolts
& Washers:
the threaded end. A lock washer is usually used under
the nut and a flat washer is used under the bolt head to
spread the load and protect surfaces.
Bolts are commonly designated using the American National Thread System as either
National Coarse (NC) or National Fine (NF). The most
commonly used general-purpose bolts have NC threads.
Figure 2-9 Bolt, Nut, Lock, and Flat Washer
Figure 2-10 Threaded Rod
Threaded rod is similar to a bolt, except that it is threaded
at both ends and has no head. Hex coupling nuts are useful in joining two pieces of
threaded rod together. They are commonly seen on
commercial/industrial fuel burner linkage assemblies connecting air
shutters to fuel valves.
Figure 2-11 Hex
Coupling Nut
Hex nuts are the most common type of nuts used in the heating trade. Lock nuts have
nylon inserts beside the threads, which prevents the nut from coming
loose when subjected to vibration or stress.
Flanged nuts have attached washers that can cover oversized holes
Figure 2-12
Hex Nut
(Figure 2-14).
Several methods are used to prevent nuts from working loose, such as using a lock
washer or tightening one nut against the other.
Figure 2-14
Flanged Nut
Figure 2-13
Lock Nut
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Anchors & Shields
Plastic anchors are used primarily for light duty fastening in concrete, brick, masonry or
drywall. The ridged body of the anchor helps eliminate spinning while the screw
Figure 2-15
Plastic Anchor
is being inserted.
Hollow-wall anchors are designed for thin materials such as drywall,
plaster, or paneling. The anchor is pushed into a pre-drilled hole and as the
Figure 2 -16 Hollow
Wall Anchor
screw is turned in, the anchor expands, securing itself to the back of the wall
or panel.
Wallboard anchors can be screwed directly into drywall without the need for a starter
hole. Screws must then be inserted into the centre of the wallboard
Figure 2-17 Wallboard
Anchor
anchor once it is installed. Wallboard anchors are used for lightweight
jobs.
Toggle bolts are used in hollow drywall, plaster, tile, and block applications. Toggle bolts
are machine screws with screwed-on spring-loaded wing nuts. Toggle
bolts need to go through the object being secured first, before the
Figure 2-18 Toggle Bolt
spring-loaded wing nut is attached. Then the wings are squeezed
together and pushed through the predrilled hole in the hollow wall. Once the wings are
through the wall, the wings will spring open against the inner side of the wall. This will
then allow the toggle bolt to be tightened, securing the object to the wall. If you
unscrew the toggle bolt after the installation, the wing nut will fall off inside the wall.
The double wedge expansion anchor functions like a lag shield. The anchor is pushed
into a pre-drilled hole in concrete. As machine screws or machine bolts
are tightened into the anchor, the two opposing wedges pull towards
Figure 2-19 Wedge
Expansion Anchor
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each other, expanding within the hole and securing the anchor body.
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Drop-in anchors are used in medium to heavy-duty applications. They are dropped into
predrilled holes in concrete. A setting tool is then used to drive the
Figure 2-20 Drop-in Anchor
plug to the right depth causing the anchor to expand. Drop-in
anchors are frequently used for overhead applications such as
Figure 2-21 Drop-in Anchor
Setting Tool
hanging pipe and ductwork.
Eye couplings are fastened to expansion anchors or threaded rod that has already been
installed. They can be used for hanging pipe, fixtures or other assemblies.
Combined with a wedge or sleeve anchor, they can be used in a variety of
Figure 2-22 Eye
Coupling
tie-down applications.
Wire Hose Clamps are self-tightening, spring tension clamps used to
secure hose material. Hose clamp pliers make installing and removing this
type of clamp easier.
Figure 2-23 Wire
Hose Clamp
Worm gear hose clamps tighten around hoses as the screw is turned. They come in a variety
of sizes.
Figure 2-24 Worm Gear
Hose Clamp
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 Twist-on wire connectors are cone shaped plastic
Electrical
Connectors:
caps that are used to connect wire ends
together. Marrettes® and Wire-Nuts® are common
types. Wire-Nuts® come in various colours according to
their size, while Marrettes® are generally black and are
numbered according to their size.
Figure 2-25 Twist On Wire
Connectors
To use either connector, you would first strip or skin the end of the wire about an inch
using wire strippers. (Figure 2-26 – 2-29) Carefully twist the wires tightly
and neatly together, using a pair of blunt-nose
Figure 2-26 Wire
Strippers
pliers. Finally, twist the wire connector on tightly
with your hands in a clockwise direction.
There are many different sizes of wire connectors. Make sure
Figure 2-27 Twist On
Connector Clockwise
to use the proper size. Each connector is rated for a minimum and maximum number of
specific sized wire that the connector can contain.
Figure 2-28 shows commonly used connectors that are attached to wire
ends using a crimping tool. The
crimping tool squeezes a metal
lining within the connector tightly
Figure 2-28 Solderless Wire End Connectors
Figure 2-29 Crimping and
Wire Stripper Combination
Tool
against the bare wire end.
There are many different types of crimping tools. Figure 2-29 shows a commonly used
crimping tool and wire stripper combination. It is always good practice to give
connectors a tug after fastening to ensure a tight, secure fit.
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 Tools make our work easier and safer. They are
Tool Safety:
usually designed with a specific purpose in
mind. Remember to always use the correct tool for a
given task. The correct tool minimizes the chance of
personal injury, injury to others, and damage to the
equipment being worked on.
Figure 2-30 Pipe Wrench
Understand and familiarize yourself with any new tool. Always
read the instructions before using the tool.
Remembering the following basic safety rules can prevent many
hazards associated with tool use:
Use the correct tool for the job.
Examine each tool for damage before using it.
Figure 2-31
Power Drill
Keep tools in good condition.
Use tools according to the manufacturer's instructions.
Many accidents have been caused by tools falling from overhead locations as well as sharp
tools carried in pockets or left in tool boxes with cutting edges exposed.
Screwdrivers, chisels, snips, or other pointed tools should never be carried in
pockets. Use a toolbox or belt.
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When carrying tools by hand, keep sharp points and cutting edges pointed away
from your body.
Do not carry tools in a manner that might interfere with the
use of your hands when climbing ladders or other such
structures.
Utilize proper tool belts that don’t interfere with your ability
to climb. Buckets can be utilized to hoist tools and material
Figure 2-32 Tool Belt
up and down from roofs or other high locations.
Select the Right Tool for the Job.
Avoid unsafe practices such as using a file or screwdriver for a pry bar, a wrench for
a hammer, or pliers instead of the proper wrench.
Keep Tools in Good Condition
Inspect your tools before using them.
Look for such things as wrenches with cracked jaws, screwdrivers with broken
points or broken handles, hammers with loose heads, dull saws, and extension cords
or electric tools with exposed wires or broken plugs. Discontinue using
defective tools.
Figure 2-33 Power Saw
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Portable Power Tools
Use a ground-fault circuit-interrupter (GFCI) with every power tool to protect yourself
against electrical shock hazards, especially in wet locations.
The GFCI continually senses imbalances in an electrical
circuit. When it senses a ground fault, or current leaking to ground Figure 2-34 ground-fault
circuit-interrupter (GFCI)
even through your body - it is designed to open the circuit
immediately to prevent the current from harming you.
Note: Although double insulation of newer power tools is designed to reduce the risk of
electrical shock, GFCl’s are the most effective means of protecting yourself against
electrical shock hazards.
Always disconnect the power cord before changing saw blades, drill bits, or making
adjustments. Do not unplug tools by pulling on the cord.
Don’t leave power tools in an overhead place where there is a possibility that they will
fall. Make sure extension cords on the floor are properly secured so they do not create
a stumbling or tripping hazard.
Do not hang power cords over nails, bolts or sharp edges. Cords should also be kept
away from oil, hot surfaces, chemicals and water.
Always wear appropriate personal protection equipment to protect your eyes, face,
ears, and body when using portable power tools.
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Wrenches
Open-end wrenches are useful in tight areas where it is not possible to use a box
wrench. The head is usually set at a 15o angle to the shaft. This permits complete
rotation of a hex nut or bolt, in a 30 o swing,
by simply flipping over the wrench.
Open-ended wrenches are available in
standard S.A.E sizes such as 1/4", 1/2",
Figure 2 - 35 Open
End Wrenches
7/16", 3/4", 1 1/4", and also in metric sizes
such as 8mm, 10mm, 14mm, 32mm etc. Selecting the proper sized wrench avoids wrench
slippage which could result in personal injury and damage to
equipment.
Adjustable open-end wrenches adjust to fit nuts and bolts of
various sizes. They are designed as a convenience tool and although
they are considerably heavier than non-adjustable wrenches, they
Figure 2-36
Adjustable Wrench
are usually weaker.
Only use an adjustable wrench when it is not possible to use the proper sized fixed
wrench. Never use it to free seized nuts and bolts. Box wrenches
completely encircle nuts and bolt heads. They may have 6 or 12
points enabling you to use a box wrench on a six-sided bolt from
Figure 2-37 Box Wrenches
a variety of angles, with a better grip, and without having to flip
the wrench over as with the open-end wrench. The limitation of box wrenches is that
they can only be used where there is enough clearance to get the wrench over the top
of the nut or bolt.
Socket wrenches have detachable heads or sockets with square drive openings that can
fit onto a wide variety of handles. The sockets can be regular or
extra deep, with square, 6, 8, or 12 point openings.
Figure 2 -38 Socket Set
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Sockets can fit over hex nuts in recessed holes, which might otherwise be inaccessible
with open-end or box wrenches.
A ratchet-type handle is most commonly used with sockets. This handle permits you to
turn the socket continuously in one direction by moving the
handle back and forth without removing the socket from the nut.
Figure 2-39 Socket Wrench
Handles
Pipe wrenches turn threaded pipes. They have a fixed lower jaw and a loose upper one
that is free to pivot in a retaining collar. The harder the wrench is pressed, the tighter it
bites down on round objects. When the handle is pulled
back, the wrench releases.
Figure 2-40 Adjustable Pipe Wrench
Pipe wrench handles are made of malleable iron or aluminum. Aluminum handled
wrenches are about 40-50% lighter than the malleable iron
type.
The Offset Pipe wrench is ideal for overhead work and
Figure 2-41 Offset Pipe Wrench
work in restricted spaces.
An End-Pattern pipe wrench is useful when working in restricted spaces, close to a wall,
or on closely spaced parallel pipelines.
Figure 2-42 End Pattern Pipe Wrench
Hex Keys (Allen Keys) are used on setscrews that
are usually recessed flush with the surface.
Figure 2-43 Allen Keys and Set Screw
Either end of the Allen key will fit inside the setscrew.
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Aviation
Snips:
 Aviation snips, originally developed for the airline
industry, are used to cut sheet metal, wire screening,
and other light material.
There are snips for right cutting, left cutting, and straight cutting.
Although all three types can be used to make straight cuts, the left or right cutting snips
cut curves more easily.
Handles are color coded for quick identification: red for left cutting, green for right
cutting and yellow for straight cutting.
Straight cutting snips are the most commonly used type. They will cut straight lines and
larger radius circles.
Figure 2-45 Straight Cutting Aviation Snips
Figure 2-44 Left Cutting Aviation Snips
Figure 2-46 Right Cutting Aviation Snips
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Pliers:
 Pliers are made in various shapes and sizes and are
designed for many different uses. Some are used for
gripping, twisting wire, or cutting wire. Make sure you
use the correct type and size of pliers or wire cutters. Do
not use pliers on nuts and bolts as they can strip easily;
use a wrench instead.
Large groove-joint pliers, also referred to as channel locks, or tongue and groove pliers, can
grip flat, square, round, or hex shaped objects. They are often used for holding smaller
diameter piping. The jaws can be set in a number of
positions by slipping the curved ridge into a particular
groove.
Figure 2-47 Channel Lock Pliers
Long-nose pliers, or needle nose pliers, are generally used to
Figure 2-48 Needle Nose Pliers
hold small objects. They can fit into small areas and are
useful in electrical wiring work. They have narrow flat jaws with serrated teeth and often
have a built-in wire cutter. Avoid bending heavy wire with needle nose pliers as the pliers
can be easily damaged.
Lineman's pliers are a combination of flat jaw and wire cutters. The end is flat with serrated
teeth and used for pulling and twisting wires. Behind the
teeth is a wire cutter.
Figure 2 -49 Lineman’s Pliers
Slip-joint pliers have both serrated teeth and coarse
contoured teeth to grip objects of different shapes. Sliding the handles apart varies the jaw
size. They can be set in two positions
Figure 2-50 Slip Joint Pliers
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Side cutting pliers are designed for cutting wire and thin metal. Do not cut hardened
wire unless the pliers or wire cutters are specifically
manufactured for this purpose.
Figure 2-51 Side Cutters
Straight jaw locking pliers clamp firmly onto objects. A knob in the handle controls the
jaw's width and tension. Closing the handle locks the jaws onto an object.
Figure 2-52 Locking Pliers
Hose clamp pliers are used to install and remove spring tension clamps.
Figure 2 -53 Hose Clamp Pliers
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 Select the proper screwdriver for the job by
Screwdrivers:
matching the screw head to the screwdriver
tip. Handles on screwdrivers are generally designed
for comfort and grip and not to protect you from
electrical shock.
When working on live electrical equipment, the screwdriver must have an insulated
handle and shaft to prevent them from conducting electricity.
A slot-headed screwdriver has a flat tip. The most common is
tapered to the tip, which is ground square.
Figure 2-54 Slot Head
A Phillips screwdriver has a cross head tip formed by grinding four flutes in the end
of a pointed blade.
Figure 2-55 Phillips
Head
Robertson screwdrivers are square-headed and provide high torque power and are
less likely to slip due to the square design that tends to stay on the head of the
screws better. This design can be quite useful when trying to get
screws into tight places.
Figure 2-56
Robertson Head
Robertson screwdrivers are generally colour-coded according to their size with
Yellow #1 being the smallest and Black #4
the largest.
Figure 2-57 Robertson ColourCoded Screwdrivers
Figure 2-58 Robertson
Screwdrivers
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A Posidrive head looks like a Phillips head but has four additional smaller cuts at 45
degree angles. It also has a square tip instead of a pointed tip, and the
Figure 2-59 Posidrive Head
posidrive screw is shallower and the cut angles are different from a
standard Phillips.
Hex Screwdrivers can be used on screws where Allen Keys are used such as setscrews
and recessed socket head screws.
Figure 2 - 60 Hex
Head
Torx screwdrivers have a star-like shape. Used in the automotive and appliance
industry.
Figure 2-61 Torx
Head
Nut drivers are used to drive hex-head screws.
Figure 2-62 Nut Driver
When working in tight areas where a normal sized
screwdriver will not fit, try an offset or a stubby screwdriver. Most screwdrivers
mentioned can be obtained in offset and stubby sizes.
Screwdrivers are designed for screws. Do not use a screwdriver for prying,
punching, chiseling, scoring, or scraping.
Do not use pliers on the end of a screwdriver handle, as the handle will become
damaged and unusable. A wrench should only be used on the square screwdriver
shank where designed for that purpose.
Do not expose a screwdriver blade to excessive heat. Heat can affect the temper of
the metal and weaken the tool.
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Common Hand Tools
Cold chisels are called cold chisels because they are used on cold metals. A cold chisel
will cut any metal softer than itself such as: steel,
aluminum, wrought iron, cast iron, brass, bronze, and
Figure 2-63 Cold Chisels
copper. Chisels come in a variety of styles with the most
common having a tip like a screwdriver.
Files come in various shapes and sizes. The length, shape, and cut distinguish most of
them from one another. The length of a file applies to its cutting
surface. The kind of file refers to its cross-sectional shape, which may
Figure 2-64 Flat File
be flat, square, round, half-round, or triangular. The cut of a file refers
to the kind of teeth or sharp serrations it has.
Most hacksaws have a tubular or flat type of frame. They can
take 10" or 12" (254 mm-304 mm) blades and can be adjustable or nonFigure 2-65 Hacksaw
adjustable. Heavier jobs require a non-adjustable 12" (304 mm)
hacksaw, which is more rugged. It is important to use the proper type of hacksaw blade
for the type of material being cut. Always follow the manufacturer's recommendations.
Material being worked on should always be properly secured.
Every trade has its own special type of hammer; such as
Figure 2-66 Hammers
bricklayer’s, carpenter’s, and roofer’s hammers.
Typical hammers used in the heating trade include nail and ball
peen.
Figure 2-67 Wire Brush
Wire brushes prepare and clean wood, metal and other surfaces by removing loose
paint, rust corrosion and other hardened material.
A riveter, or pop rivet gun can join thin metal material
together. Some riveters have exchangeable heads, which
Figure 2-68 Rivet Gun
are usually stored on the gun handle that can accommodate various sizes of rivets.
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Power Tools
The reciprocating saw is a portable tool that works like a hand-saw in that it imitates the
back-and-forth motion of a hand saw. It cuts on the
return stroke. Various types of blades allow the saw to be
used to cut different types of material.
Figure 2-69 Reciprocating Saw
Portable circular saws offer portability, strength, and speed. They are used to cut
through walls, floors, ceilings, roofs etc. Although these saws are
primarily a woodworking tool, interchangeable blades are available
for cutting different materials including brick and metal. The
diameter of the blade determines the size of the saw. 7" and 7 1/4"
Figure 2-70 Circular Saw
(177mm and 184mm ) saws are the most common.
Portable grinders are excellent for all kinds of metal sanding and grinding applications.
This includes smoothing castings, welds, and general metal fabrication work. Typical
wheel sizes are 5", 7", or 9" (127mm, 177mm, or 228 mm). Wheels
may be made of aluminum oxide for tough cutting, or silicon carbide
for softer materials such as masonry.
Figure 2-71 Portable Grinder
A typical bench grinder has two aluminum oxide wheels. The wheels can range in size
from 4" X 1/2” to 8" X 1 " (100 mm X 12mm to 230mm X 25 mm). Usually,
one wheel will be medium-coarse and the other medium-fine. The bench
grinder is a good tool for sharpening and smoothing the edges of drill bits
and other tools.
Figure 2-72 Bench
Grinder
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Powder-actuated tools like other tools can make your work easier, however this tool is
as dangerous as a loaded gun. You must be specially trained and certified before using
it.
A powder-actuated tool uses a powder charge the way a gun shoots a bullet. It "shoots"
a fastener into a surface, such as concrete or steel. Improperly used, it is capable of
severe injury or even death.
The power loads for powder-actuated tools are essentially
blank cartridges. They are color and number coded for
power levels. Always follow the manufacturer's
Figure 2-73 Powder-Actuated
Fastening Gun and Charge
instructions to select the correct power load for the material being firing into. The
powder charge or shot must be stored in a dry secure location.
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Measurement:
It is hard to find a task within our trade that
does not require some type of measuring.
The following measurements are commonly used in the heating trade:
Distance and size
length, width, and height of equipment, materials, and areas.
Volume
tanks, piping, boilers, venting, ductwork, combustion chambers, spaces, and fuel
burner input.
Pressure
gas, steam, water, oil, furnace, stack, and air.
Circumference
piping, venting, blower fan wheels, shafts, bolts, and openings.
Surface Area
combustion and ventilation air louvers, diffusers, grills, boiler heating surfaces, and
floor area.
Electrical
resistance, amperage, voltage.
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How is the area of a rectangle calculated?
The area of a rectangle is calculated by multiplying its length by its width. A = L x W.
The answer is expressed in square units (square inches, square feet, square meters
etc).
Example: What would be the overall surface area of
the combustion air dampers shown (Figure 2 - 74)?
Answer: 3 feet x 2 feet = 6 square feet. The overall
surface area would equal 6 square feet (0.56 m2).
Figure 2 - 74 Air Louvers,
Measuring Area
How is the volume of a cube calculated?
The volume of a cube is calculated by multiplying the cube's length by its width and
then by its height. V = L x W x H. The answer is expressed in cubic units (cubic
inches, cubic feet, cubic meters etc).
Example: What would be the overall internal area of the boiler shown
(Figure 2 - 75)?
Answer: 6 feet x 4 feet x 5 feet = 120 cubic feet.
The overall internal area would equal 120 cubic
feet (3.4 m3).
Figure 2-75 Commercial Boiler Measuring
Volume of Cube
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How is the diameter and radius of a circle measured?
The diameter is the distance across a circle at the widest point. It can be measured
directly with a ruler or tape measure. Half of the diameter is
called the radius, therefore, if the pipe (Figure 2-76) had a
diameter of 2 inches (50 mm), its radius would equal 1
Figure 2-76 Measuring Diameter
with Ruler
inch (25mm).
How is the circumference of a circle measured?
The circumference of a circle is the distance around the outside edge. It can be
measured using a tape measure or by a calculation. A
special number called 'pi' is used for the calculation. Pi
is approximately equal to 3.14. By multiplying 3.14 by
the diameter of a circle you can determine its
Figure 2-77 Measuring Circumference with
Tape Measure
circumference. C = 3.14 x D
Example: If the pipe (Figure 2-76) had a diameter of 2 inches (50 mm), you would
multiply: 3.14 x 2 = 6.28 inches. The circumference of the above pipe would equal
6.28 inches (159 mm).
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How is the area of a circle measured?
The area of a circle is determined multiplying 3.14 by the radius squared.
A = 3.14 x R2. Example: If the above pipe has a diameter of 2 inches (50 mm), its
radius would equal 1 inch. (25 mm) Therefore multiply 3.14 x 12 = 3.14 square
inches. The area of the above pipe would equal 3.14 square inches (20 cm2)
How is the volume of a cylinder measured?
The volume of a cylinder is calculated by multiplying the area of the cylinder by the
length of the cylinder. V = A x L
Example: The pipe (Figure 2-77) has an area of 3.14. sq. in. If the total length of the
pipe were 10 inches (254 mm) multiply 3.14 x 10 = 31.40 cubic inches. The volume
of the above pipe equals 31.40 cubic inches.
For use with Instructor facilitated
G3 Blackboard Online course only
© 2021. Gas Technician III Learning Package by Clarke Petty Version 6.0
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Measurement Tools
Retractable tape measures have spring loaded metal rulers that retract into a round
metal housing. The ruler has a metal catch on the end, making it easier to measure long
distances without help. It usually has a belt clip as well as a locking
mechanism.
Figure 2-78 Tape Measure
A square consists of two arms set at right angles to each other. Squares are used to
check the accuracy of sides, edges, and surfaces. The square also
makes a good guide for drawing straight lines across materials.
Figure 2-79 Square
Steel rulers are available in standard and metric graduations. Steel rulers make excellent
straight edge guides for cutting or scribing.
Figure 2-80 Steel Ruler
Levels work on the principal that a still body of water is always horizontal. The
important part of any level is the vial. The vial is the curved or barreled
Figure 2-81 Level
glass that contains a clear liquid, which may be alcohol, oil or chloroform.
There is a bubble of air in the liquid, which floats to the highest point of
the curve where two lines are marked on the vial. When the level is "true" the bubble
will come to rest between the two marked lines.
For use with Instructor facilitated
G3 Blackboard Online course only
© 2021. Gas Technician III Learning Package by Clarke Petty Version 6.0
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The plumb bob is a pointed weight attached to a length of line, which attaches to a slot
in the plumb bob’s cap. A plumb bob is used to make sure
that an object is truly vertical, or that an object is directly
under a certain point on a ceiling.
To use the plumb bob, you hold the end of the line at the
required point and allow the bob to settle. It must hang free.
Figure 2-82 Plumb Bob
You can then mark the point below the plumb bob or mark the edge of the plumb bob
line. This tool is useful for ensuring vent pipe is centered when the vent pipe has to go
through an exact point in a ceiling or roof.
A slide caliper is used to measure internal and external dimensions up to 3¼ “ (81mm).
One jaw of the slide caliper is fixed, while the other is part of a slide, which moves up or
down until both jaws come into contact with the material being measured.
The slide has a knurled clamp nut that can be tightened to secure the
measurement. They are available with imperial and metric graduations.
Figure 2-83 Slide
Caliper
A drill gauge is a template for measuring the size of a drill bit. You insert a drill bit into
each hole; find the one that fits and read the indicated size marked beside the hole.
Thumb drills are used to drill gas orifices. Gas orifices are designated
according to Drill Manufacturer’s Standard (D.M.S) drill numbers, in which the area
Figure 2-84
Drill Gauge
of the orifice corresponds to the area created by the D.M.S. drill.
Figure 2-85
Thumb Drills
**End of Module - Return to Course and Complete Associated Online Test(s)**
For use with Instructor facilitated
G3 Blackboard Online course only
© 2021. Gas Technician III Learning Package by Clarke Petty Version 6.0
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