1. Piping Drafting & Drawing
ERT 243 COMPUTER AIDED DESIGN AND DRAFTING (CAD)
Piping Drafting & Drawing
Siti Kamariah Md Sa’at
School of Bioprocess Engineering, UniMAP

2. Pipe Drawing
Almost every conceivable fluid is handled in pipes during its production, processing, transportation and use.
Piping also used as a structural element in column and handrails.
For  these  reasons,  drafters  and engineers should  become familiar with plumbing and piping drawings.
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.
The two types of projection used in plumbing and piping diagrams are projection orthographic and isometric (pictorial).

3. ORTHOGRAPHIC PLUMBING PIPE DRAWINGS
Orthographic  pipe drawings show single pipes either straight or bent in one plane only.
Orthographic pipe drawings may be single-line drawings where you draw the center line of the pipe as a thick line and add valves and fittings, or double- line drawings where you draw each valve and fitting.

4. ORTHOGRAPHIC PLUMBING PIPE DRAWINGS
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 lay out and produce a piping system.
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.

5. ORTHOGRAPHIC PLUMBING/ PIPE DRAWINGS
Single-line orthographic drawing
Double-line orthographic drawing

6. ISOMETRIC (PICTORIAL) PLUMBING PIPE DRAWING
Isometric pipe drawings use to draw for all pipes bent in more than one plane.    
You may use either the single-line or double line method.
The  finished  drawings  are easier to understand in pictorial format than as orthographic line drawings.

7. ISOMETRIC (PICTORIAL) PLUMBING PIPE DRAWING
Double-line isometric pipe drawing
Single-line isometric pipe drawing

8. CROSSING PIPES
To show pipes that cross each other without connection, draw lines without interruption.    
When it is important to show that one pipe passes behind another, break or interrupt the line representing the pipe fartherest from the viewer

9. Crossing Pipes
Pipe connection

10. CONNECTION
Permanent connections, whether made by welding or other processes such as gluing or soldering, should be shown on the drawing by a heavy dot
Draftsman   normally   will   use   a   general   note   or specification to describe the type of connection. Detachable connections are shown by a single thick line.
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.

11. Connection
Permanent  and  detachable connections

12. 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.

13. Fittings
Indicating the ends of pipe fittings

14. FITTINGS Each opening on a fitting is identified with a letter.
On crosses and elbows, you always read the largest opening first and then follow the alphabetical order  in  Figure  in next slides
On  tees,  45-degree, Y-bend or laterals and double- branch elbows, read the largest opening first, the opposite opening next and the outlet last.

15. Plumbing  fittings

16. Common pipe line symbols

17. Common piping symbols

18. Cont.

19. Common plumbing symbols

20. Valves
Because of the diversity 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.

21. 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.

22. Globe valve
A  globe  valve  is  a   linear  motion  valve used to stop, start, and regulate fluid flow.

23. Butterfly valve
A   butterfly   valve,   illustrated   in Figure   19,   is   a   rotary   motion valve    that    is    used    to    stop, regulate,    and    start   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.

24. 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.

26. Relief Valve
Relief valves are typically used for incompressible fluids such as water or oil.  Safety valves are typically used for compressible fluids such as steam or other gases.   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.

27. ...