LECTURE 7: PIPING
DRAFTING & DRAWING
Prepared by: Nor Helya Iman Bt. Kamaludin
helya@unimap.edu.my
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Industrial Process Piping
 Industrial process piping involves the used of
piping to transport fluids between storage
tanks and processing equipment.
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Types of Piping
 Plumbing
 Civil Piping
 Transportation Piping
PVC Pipes
Infrastructure Pipes
Fuel Pipes
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Uses of Industrial Piping




Water
Natural gas
Electric power
Specialty items like paper pulp or liquid
foods
 Sewer
 Storm drains
 And more…
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Pipe Drafting
 Pipe drafting utilizes many different types of
drawings:
 Flow diagrams
 Structural and site plans
 Mechanical and instrumentation drawings
 Pipe can be drawn in two forms: double line &
single line.
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Facts about Pipe Drafting
Most common & complex type of pipe drawing are plans and
sections that show building outlines.
Equipment shown on piping plans and section drawings are drawn
as outlines to illustrate clearances and access.
Piping drawings are normally dimensioned in an architectural
style.
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Facts about Pipe Drafting
Single-line
Drawings (time
saving method)
Double-line
Drawings (easiest
to interpret)
The centerline is
used to represent
the pipe
Used extensively
by equipment
manufacturers
Standard pipe
symbols are used
Used to portray
large diameter
pipe
Pipe & fittings
are drawn as
heavy lines
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Pipe Drawing
Piping drawings show the size and location of pipes, fittings, and
valves. A set of symbols has been developed to identify these
features on drawings.
Using scale drawing, it provides plan, elevation and section views.
All equipment, fittings, dimensions and notes are shown on this
type of drawing.
The two types of projection used in plumbing and piping diagrams
are projection orthographic and isometric (pictorial).
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ORTHOGRAPHIC PLUMBING PIPE
DRAWINGS
An orthographic drawing that shows all of the pipe and fittings
needed to assemble a segment of piping
Orthographic pipe drawings can be:
- single-line drawings: the centerline which represent the pipe is drawn
as a thick line and add valves and fittings, OR
- double- line drawings: need to draw each valve and fitting that are
required in piping system
Drafters usually use single-line drawings to shows the arrangement
of pipes and fittings.
Single-line drawings take less time and show all information
required to layout and produce a piping system.
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ORTHOGRAPHIC PLUMBING PIPE
DRAWINGS (CONT’D)
Double-line drawings are generally used in
applications, such as catalogs, where visual appearance
is more important than drawing time (require more time
to draw)
Orthographic pipe drawings are sometimes used on
more complicated piping systems.
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ORTHOGRAPHIC PLUMBING PIPE
DRAWINGS (CONT’D)
Double-line orthographic
drawing
Single-line orthographic
drawing
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ISOMETRIC (PICTORIAL) PLUMBING
PIPE DRAWING
Isometric pipe
drawings use
to draw for all
pipes bend in
more than one
plane.
Apply either
the single-line
or double line
method.
The finished
drawings are
easier to
understand in
pictorial format
than as
orthographic line
drawings.
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ISOMETRIC (PICTORIAL) PLUMBING
PIPE DRAWING (CONT’D)
Single-line isometric
pipe drawing
Double-line isometric
pipe drawing
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CONNECTION
Draftsman normally will use a general note or
specification to describe the type of connection.
The specification, a general note, or bill of material will list
the types of connections such as flanges, unions, or
couplings and whether the fittings are flanged or threaded.
Permanent connections, whether made by welding or
other processes such as gluing or soldering, should be
shown on the drawing by a heavy dot.
Detachable connections are shown by a single thick line.
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Connection
Permanent and detachable connections
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FITTINGS
Sometimes standard symbols for fittings like tees, elbows, crossings, and
so forth, are not shown on drawings.
Use the circular symbol for a tee or elbow when it is necessary to show
piping coming toward or moving away from the viewer.
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Indicating the PTT
ends
pipe fittings
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Types of Pipe
 Cast Iron
 Clay
 Steel
 Glass
 Copper & Copper Alloys
 Wood
 Plastic
 Steel Tubing
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Plumbing
fittings
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Common pipe line symbols
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Common piping symbols
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Common plumbing
symbols
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Valves
Because of the variety of the types of systems, fluids, and environments in which valves
must operate, a vast array of valve types have been developed.
Examples of the common types are the globe valve, gate valve, ball valve, plug valve,
butterfly valve, diaphragm valve, check valve, pinch valve, and safety valve.
Each type of valve has been designed to meet specific needs. Some valves are capable
of throttling flow, other valve types can only stop flow, others work well in corrosive
systems, and others handle high pressure fluids.
All valves have the same basic component and function to control flow.
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Gate Valves
 A gate valve is a linear
motion valve used to
start or stop fluid flow;
 However, it does not
regulate or throttle flow.
 The name gate is derived
from the appearance of the
disk in the flow stream.
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Globe valve
 A globe valve is a linear
motion valve used to
stop, start, and regulate
fluid flow.
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Butterfly valve

A butterfly valve is a rotary
motionvalve that is used to
start,
stop,
and
regulate
fluid flow.

Butterfly valves are easily and
quickly operated because a 90o
rotation of the handle moves the
disk from a fully closed to fully
opened position.

Larger butterfly valves are actuated
by handwheels connected to the
stem through gears that provide
mechanical advantage at the
expense of speed.
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Check valve
Check valves are designed to prevent the reversal of flow
in a piping system.
These valves are activated by the flowing material in the
pipeline.
The pressure of the fluid passing through the system opens
the valve, while any reversal of flow will close the valve.
Closure is accomplished by the weight of the check
mechanism, by back pressure, by a spring, or by a
combination of these means.
The general types of check valves are swing, tilting-disk,
piston, butterfly, and stop.
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Relief Valve
Relief valves are
typically used for
incompressible fluids
such as water or oil.
Safety valves can
often be distinguished
by the presence of an
external lever at the
top of the valve body,
which is used as an
operational check.
Safety valves are
typically used for
compressible fluids
such as steam or other
gases.
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Models of Pipe Layouts
Models are often used to illustrate and
troubleshoot the layout of a piping system
The advantage is the ability to see clearances and
interferences
Operators can be trained on the piping system
using a model.
Today 3-D CAD models are being utilized.
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Example of pipe layout model
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THE END…
THANK YOU 
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