1. PIPING DRAWINGS
C H A P T E R T W E N T Y- O N E

2. OBJECTIVES
1. Identify cast iron, brass, copper, and thermoplastic pipe and
tubing fittings.
2. Draw and label common pipe joints using ANSI/ASME standard
designations.
3. Draw a multiview or pictorial piping drawings using standard
schematic symbols.
4. Draw the schematic symbols for valves and identify flow
direction.

3. Piping Drawings

4. UNDERSTANDING PIPING DRAWINGS
CAD systems have standard symbols available, and templates for drawing piping symbols are a convenient timesaver when you are sketching piping.
Standard Piping Symbols

5. Single and Double Line PIPING DRAWINGS
Piping Symbols Used in a Double-Line Drawing and a Single-Line Drawing
(Courtesy of Softdesk, Inc.)
Single-Line Drawing
Double-Line Drawing

6. STEEL AND WROUGHT IRON PIPE
Steel or wrought iron pipe is used for water, steam, oil, and gas.
The American National Standards
Institute/American Society of Mechanical Engineers (ANSI/ASME) has developed dimensions for 10 different schedules of pipe

7. CAST IRON PIPE
Cast Iron Pipe, Thicknesses and Weights—American National Standard
Cast Iron Pipe Flanges and Fittings

8. SEAMLESS BRASS AND COPPER PIPE
It is used in plumbing for supply, soil, waste drain, and vent lines. It is also particularly suitable for process work where formation of scale or oxidation in steel pipe would be troublesome. Brass pipe and copper pipe are available in straight lengths up to 12'.
Brass pipe, generally known as red brass pipe, is an alloy of approximately 85% copper and 15% zinc. Copper pipe is practically pure copper with less than 0.1% of alloying elements.
Brass pipe and copper pipe should be joined with fittings of copper-base
alloy to avoid galvanic action resulting in corrosion.

9. COPPER TUBING Fittings
Copper tubing is often used in applications for nonferrous construction in sizes
below 2". It is suitable for process work, for plumbing, and for heating systems
(particularly radiant heating).
Fittings
Solder joints are also known as capillary joints because the annular space between the tube and the fitting is so small that the molten solder is drawn into the space by capillary action.

10. PLASTIC AND SPECIALTY PIPES
Pipe and tubing of other material, such as aluminum and stainless steel, are also
available. A wide variety of plastic pipe, both rigid and flexible, is used in construction.
Plastic pipe is lightweight, corrosion proof, resistant to many chemicals, and has a smooth inner surface which offers low flow resistance.
PVC (polyvinyl chloride)
CPVC (chlorinated polyvinyl chloride)
HDPE (high-density polyethylene)

11. PIPE FITTINGS
Pipe fittings are used to join lengths of pipe, to provide changes of direction, to provide branch connections at different angles, or to effect a change in size.

12. PIPE JOINTS
screwed
flanged
welded
Completed Weld
soldered

13. VALVES
Valves are used to stop or regulate the flow of fluids in a pipeline.
Common types are:
Single-Line Valve Drawing
Double-Line Valve Drawing
Gate valves
Globe valves
Check valves
Pressure-reducing valves
Safety valves

14. Solenoid-Actuated Valves
Solenoid valves are electromechanical devices often used to regulate the flow of liquid or gas.
Two-Way Two-Position, Normally Closed Solenoid Valve. (Courtesy of Spartan Scientific.)

15. AMERICAN NATIONAL STANDARD CODE FOR PRESSURE PIPING
The American National Standards Institute has adopted an American National Standard Code for Pressure Piping (ANSI/ASME B ). This compilation of recommended practices and minimum safety standards covers various types of piping, such as power piping, industrial gas and air piping, oil refinery piping, oil transportation piping, refrigerating piping, chemical industry process piping, and gas transmission and distribution piping.
CODE
Book