Chapter 21

Piping Drawings

Chapter 21

Technical Drawing 13th EditionGiesecke, Mitchell, Spencer, Hill Dygdon, Novak, Lockhart

© 2009 Pearson Education, Upper Saddle River, NJ 07458.

All Rights Reserved.2

Objectives

• Identify cast iron, brass, copper, and thermoplastic pipe and tubing fittings

• Draw and label common pipe joints using ANSI/ASME standard designations




Objectives (cont.)

• Draw multiview or pictorial piping drawings using standard schematic symbols

• Draw the schematic symbols for valves and identify flow direction




Standard Symbols




Types of Drawings

• Two types of drawings are common for piping systems:• Single-line drawings show the center-

line of the pipe• Double-line drawings show two lines

representing the pipe diameter




Types of Drawings




Types of Drawings

• Axonometric drawings may be used




Types of Drawings

• Piping may also be shown in a dimetric drawing or in orthographic projection

• In a developed piping drawing, vertical pipes are revolved into the horizontal plane or horizontal pipes revolved into the vertical plane so the entire installation can be shown on one plane




Types of Drawings




Dimensioning Piping Drawings• In dimensioning piping drawings,

give distances from:• Center to center,• Center to end, or• End to end of fittings or valves

• Give the lengths of all straight runs • Show the size of each pipe




Dimensioning Piping Drawings




Steel and Wrought-Iron Pipe• Steel or wrought-iron pipe is

commonly used for water, steam, oil, and gas

• Steel pipe is available as:• Black pipe for natural gas• Galvanized pipe for water distribution




Cast-Iron Pipe

• Cast-iron (C.I.) pipe is used for water or gas service and as soil pipe

• Generally water and gas pipes are connected with bell and spigot joints or flanged joints• Cast-iron pipe is brittle and settling can

cause fracture unless the joints are sufficiently flexible




Cast-Iron Pipe Joints




Seamless Brass and Copper Pipe• Brass and copper pipe is used in

plumbing for supply, soil, waste, drain, and vent lines

• Brass and copper pipe should be joined with fittings of copper-base alloy to avoid corrosion• Both screwed and flanged fittings are

available




Screwed Fittings




Copper Tubing

• Copper tubing is used in applications for nonferrous construction

• It is suitable for process work, for plumbing, and for heating systems

• Copper tubing joints are made with flared joints or solder joints




Copper Tubing




Solder Fittings




Plastic and Specialty Pipes

• 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




Plastic and Specialty Pipes

• Types of plastic pipes include:• PVC (polyvinyl chloride)• CPVC (chlorinated polyvinyl chloride)• HDPE (high density polyethylene)




Pipe Fittings

• Pipe fittings are used to:• Join lengths of pipe• Provide changes of direction• Provide branch connections at

different angles• Effect a change in size




Pipe Fittings




Pipe Joints

• The joints between pipes, fittings, and valves may be:• Screwed• Flanged• Welded• Soldered




Valves

• Valves are used to stop or regulate the flow of fluids in a pipe line and include:• Globe valves• Check valves• Gate valves• Solenoid actuated valves

Chapter 21

Documents

Transcript of Chapter 21