DESN 100: Week 4

Brief Overview of • Industrial piping• Structural drafting• Civil drafting• HVAC

• Electrical Schematics

Industrial Process Piping

Definitions

• Piping– Any kind of conduit used in a wide range of

applications• Plumbing– Small diameter pipes that carry liquids, solids, or

gases• Water• Natural gas• Waste

Definitions

• Process piping– Transport of fluids between storage tanks and

process equipment• Transportation piping– Carry products hundreds of miles• Petroleum products• Gases• Coal slurries

Definitions

• Pipe drafting– Visualization of pipes and fittings in various

orthographic and pictorial views• Double line• Single line

– Most visualization problems for beginners• Isometric• Flow diagram

– Schematic, non-scale diagram of system layout

Double- and Single-Line Drawings

Definitions

• Piping drawing– Most complex• Scale drawing• Provides several views

– Plan– Elevation– Section

• All equipment, dimensions, and notes shown• Drawn from flow diagrams, manufacturer

specifications, and mechanical drawings

Definitions

• Piping isometric– Pictorial drawing– Illustrates pipe run in three dimensions– Information from piping drawings

• Spool drawing– Drawn orthographically– Shows all pipe and fittings used to assemble a

segment– Usually non-scale

Structural engineering

– Associated with commercial steel and concrete buildings

– Engineer components of a building or structure• Skyscrapers• Bridges

Definitions

• Structural drafting– Independent of or cross-referenced to other

drawings• Architectural• Plumbing• HVAC

Civil Drafting

• Graticules– Two sets of grid lines• Latitude

– Lines that divide the earth horizontally– Parallels

• Longitude– Lines that divide the earth vertically– Meridians

Definitions

• Prime meridian– Zero line of longitude– Runs through Greenland

• Local meridians– All other meridian lines

Definitions

• Degrees– Divided into components• Degrees• Minutes (60 minutes = 1 degree)• Seconds (60 seconds = 1 minute)• E.g., 124° 45' 12“• Conversion to decimal degrees

– 124 + (45/60) + (12/3600)

Definitions

• Great circle– Direction around earth from a given point in

relation to the latitude and longitude coordinates• Azimuth– Angle • Moving clockwise• Between meridian at the starting point and the great

circle

Azimuth

Property Descriptions

Metes and Bounds

• Length– Mete

• Bearing– Bound

• Primary form of legal description– 19 states, including 13 original colonies

Metes and Bounds

Rectangular System

• Used in public-land states• Meridians named separately– E,g, First principal meridian• Western boundary of Ohio

• Parallels are all named the same– Baseline

Rectangular System

• Townships– Six-mile square blocks– Arranged in columns (ranges)– Divided into 36 squares (sections)• One square mile• Divided into fourths (quarters)

– Divided into fourths (quarter-quarter sections)

• Land description– Begins with smallest portion

Rectangular System

Lot and Block

• Established from either of two other systems– Rectangular– Metes and bounds

• Subdivision – Given a name– Divided into lots

HVAC

HVAC

• Purpose– To provide air movement or exchange within a

structure• Also known as “mechanical systems”• Residential structures– Do not require plans unless complex

• Commercial structures– Use floor plan as overlap to begin mechanical

systems drawings

HVAC Systems

• Central forced-air systems– Most common for climate heating and air

conditioning• Thermostat starts cycle• Fan forces air into ducts• Ducts connect to diffusers, or air supply registers• Cycle begins again

Central Forced-Air System

HVAC Systems

• Refrigeration– Most common type of cooling system– Components• Evaporator / Cooling coil• Air pump / Compressor• Condenser• Expansion valve

HVAC Systems

• Hot water system– Water circulated through radiators or convectors– Circulator moves water through system– Water kept at temperature between 150 and 180

degrees F.

HVAC Systems

• Zoned control system– Allows for one or more heaters and one

thermostat per room– Flexible

• Radiant heat– Control surface temperatures– Minimize excessive air movement– Piping or wiring in ceiling or floor

HVAC Systems

• Heat pump– Forced-air central heating and cooling– Uses compressor and circulating liquid gas

refrigerant– Heat extracted from outside air and pumped

inside– Acts as a dehumidifier when cooling

Heat Pump

Pollutants

• Influence choice of ventilation• Types– Moisture– Carbon monoxide– Airborne pathogens– Tobacco smoke– Formaldehyde– Radon– Common household products

Electrical and Electronic Schematic Drafting

Pictorial

• Represent circuit in three dimensions• Realistic• Easy to understand• Uses– Catalogs– Brochures– Service manuals– Assembly drawings

Pictorial

Schematic

• Series of lines and symbols– Electrical current path– Circuit components

• Types– Block– Wiring– Schematic wiring

Schematic

Block Diagram

• Simplified version of schematic• Minimum detail of component• No connections at individual terminals

Block Diagram

Wiring Diagram

• Shows all interconnections of system components

• Referred to as point-to-point interconnecting wiring diagrams

• More detailed than schematic

Wiring Diagram

Schematic Wiring Diagram

• Simplicity of schematic• Completeness of wiring diagram– Circuit is series of lines and symbols• Electrical current path• Circuit components

– Connection terminals shown

Schematic Wiring Diagram

Highway Wiring Diagram

• Representation of point-to-point interconnecting wiring– Simplified and condensed

• Uses– Fabrication– Quality control– Troubleshooting

Highway Wiring Diagram

Cable Diagram

• Associated with multiconductor system• Also known as cable harness diagrams• Provide – Circuit destination– Number of leads– Conductor type– Power rating

Cable Diagram