Symbol Reference
Plumbing Plan Symbols Guide
Complete reference for pipe types, fixtures, valves, and fittings on plumbing drawings. For the abbreviations used alongside these symbols, see our plumbing abbreviations guide.
Reading Plumbing Drawings
Plumbing plans show pipes as single lines with labels (CW, HW, S, etc.). Pipe sizes are typically shown as diameter (e.g., 2" CW). Slope is indicated for drainage lines (e.g., 1/4"/ft). Understanding line weights helps distinguish between different pipe systems on drawings.
Pipe Types
| Symbol | Meaning | Notes |
|---|---|---|
| ——CW—— | Cold Water | Often blue on colored drawings |
| ——HW—— | Hot Water | Often red on colored drawings |
| ——HWR—— | Hot Water Return | Recirculation line |
| ——S—— | Sanitary Sewer | Waste line to sewer |
| ——V—— | Vent | Venting for drainage |
| ——SD—— | Storm Drain | Roof/site drainage |
| ——G—— | Gas | Natural gas supply |
| ——FP—— | Fire Protection | Sprinkler supply |
Fixtures
| Symbol | Meaning | Notes |
|---|---|---|
| ◯ | Floor Drain | Circle with drain indication |
| ◻ | Water Closet (Toilet) | Rectangular outline with tank |
| ▭ | Urinal | Wall-mounted fixture |
| ◠ | Lavatory (Sink) | Semi-circle or oval |
| ▢ | Kitchen Sink | Rectangle, often double bowl |
| ⌓ | Shower | Square with drain |
| □ | Bathtub | Rectangle with drain end marked |
| ⊕ | Cleanout | Circle with cross |
Valves & Controls
| Symbol | Meaning | Notes |
|---|---|---|
| ⊗ | Gate Valve | Full bore shutoff |
| ◇ | Globe Valve | Throttling/control valve |
| ⊘ | Ball Valve | Quarter-turn shutoff |
| ◈ | Check Valve | Prevents backflow |
| ▷ | Pressure Reducing Valve | PRV - reduces water pressure |
| △ | Backflow Preventer | BFP - prevents contamination |
| ⊙ | Pressure Gauge | Monitors system pressure |
Equipment
| Symbol | Meaning | Notes |
|---|---|---|
| □WH | Water Heater | Tank or tankless |
| □P | Pump | Circulation or booster |
| ▣ | Grease Interceptor | Kitchen waste treatment |
| ⬡ | Expansion Tank | Thermal expansion control |
| ◻HB | Hose Bibb | Exterior faucet |
| ⊞ | Water Meter | Utility metering point |
Fittings
| Symbol | Meaning | Notes |
|---|---|---|
| ├ | Tee | Branch connection |
| ┼ | Cross | Four-way connection |
| ∟ | 90° Elbow | Direction change |
| ∠ | 45° Elbow | Gradual direction change |
| ◇ | Reducer | Pipe size change |
| ⊐ | Cap | End of line |
| ⊥ | Union | Removable connection |
Common Plumbing Abbreviations
CW
Cold Water
HW
Hot Water
HWR
Hot Water Return
S
Sanitary
V
Vent
SD
Storm Drain
G
Gas
FD
Floor Drain
CO
Cleanout
RD
Roof Drain
WC
Water Closet
LAV
Lavatory
HB
Hose Bibb
DF
Drinking Fountain
PRV
Pressure Reducing Valve
BFP
Backflow Preventer
Related Resources
Plumbing Abbreviations
Common abbreviations on plumbing and fire protection drawings.
How to Read Plumbing Drawings
Step-by-step guide to interpreting plumbing plans.
Fire Protection Symbols
Sprinklers, alarms, and equipment symbols on drawings.
How to Read MEP Drawings
Understanding mechanical, electrical, and plumbing drawings together.
Solutions for Plumbing Contractors
How Articulate helps plumbing contractors review drawings.
Plumbing Coordination Guide
Best practices for coordinating plumbing across disciplines.
Coordinate Plumbing with Architecture
Plumbing fixtures shown on P sheets must align with architectural plans. Articulate automatically checks fixture locations, clearances, and accessibility compliance across disciplines.
Try Automated Coordination