[ RESOURCES ] / SYMBOLS
Engineering drawing symbols
213 symbols in 5 libraries, each with its meaning, the forms of every standard that uses it and free SVG files and PDF charts. Drawn by the team behind the completions platform offshore projects have run on since 2014.
- Process and instrumentation · 92 symbolsP&ID symbolsValves, pumps, vessels, heat exchangers, instruments, line types and fittings, with the ISO and IEC forms beside the US ones.ISA 5.1, ISO 10628, PIP, DIN, IEC 62424
- Electrical · 34 symbolsSingle line diagram symbolsBreakers, switches, fuses, transformers, CTs, relays and meters for electrical one-lines, plus the ANSI device numbers.ANSI / IEEE 315, IEC 60617, IEEE C37.2
- Electrical · 34 symbolsElectrical symbolsResistors, capacitors, diodes, transistors, switches, push buttons, relay coils and contacts, fuses, breakers, grounds and meters for schematics and circuit diagrams.ANSI / IEEE 315, IEC 60617
- Fabrication and structural · 26 symbolsWelding symbolsGroove, fillet, plug, spot and seam welds, supplementary symbols and the parts of the welding symbol, for fabrication and structural drawings.AWS A2.4, ISO 2553
- Piping · 27 symbolsPiping isometric symbolsButt and field welds, flanges, elbows, tees, reducers, blinds, valves and the annotations that place a line in the plant.ISO 6412-2, common practice
- Gate valve
- Globe valve
- Ball valve
- Check valve
- Butterfly valve
- Plug valve
- Diaphragm valve
- Needle valve
- Angle valve
- Three-way valve
- Four-way valve
- Normally closed valve
- Control valve
- Motor operated valve
- Solenoid valve
- Piston actuated valve
- Hand operated valve
- Pressure regulator
- Shutdown valve
- Pressure safety valve
- Rupture disc
- Flame arrestor
- Centrifugal pump
- Positive displacement pump
- Gear pump
- Screw pump
- Centrifugal compressor
- Reciprocating compressor
- Fan or blower
- Turbine
- Agitator
- Vertical vessel
- Horizontal vessel
- Column
- Cone roof tank
- Floating roof tank
- Sphere
- Open tank
- Silo or hopper
- Shell and tube heat exchanger
- Plate heat exchanger
- Air cooler
- Fired heater
- Cooling tower
- Kettle reboiler
- Filter
- Y-strainer
- Basket strainer
- Cyclone
- Field-mounted instrument
- Panel-mounted instrument
- Behind-panel instrument
- Local panel instrument
- DCS shared display
- PLC function
- Computer function
- Interlock
- Pressure gauge
- Pressure transmitter
- Level transmitter
- Flow transmitter
- Temperature transmitter
- Level gauge
- Orifice plate
- Venturi
- Rotameter
- Magnetic flow meter
- Thermowell
- Process line
- Minor process line
- Pneumatic signal line
- Electrical signal line
- Hydraulic signal line
- Capillary tube
- Data link
- Mechanical link
- Electromagnetic signal
- Heat traced line
- Jacketed line
- Concentric reducer
- Eccentric reducer
- Flange
- Blind flange
- Spectacle blind
- Pipe cap
- Expansion joint
- Flexible hose
- Steam trap
- Sight glass
- Drain
- Vent
- Off-page connector
- Generator
- Motor
- Battery
- Transformer
- Three-winding transformer
- Current transformer (CT)
- Voltage transformer (VT)
- Circuit breaker
- Draw-out circuit breaker
- Low voltage circuit breaker
- Disconnect switch
- Load break switch
- Earthing switch
- Contactor
- Fuse
- Fused switch
- Automatic transfer switch
- Protective relay
- Surge arrester
- Ground
- Neutral grounding resistor
- Ammeter
- Voltmeter
- Energy meter
- Busbar
- Connection
- Crossing, not connected
- Capacitor bank
- Reactor
- Variable frequency drive
- Rectifier
- Inverter
- UPS
- Load
- Resistor
- Variable resistor
- Potentiometer
- Capacitor
- Polarised capacitor
- Inductor
- Transformer
- Diode
- LED
- Zener diode
- NPN transistor
- PNP transistor
- SPST switch
- SPDT switch
- Push button (NO)
- Push button (NC)
- Relay coil
- Normally open contact
- Normally closed contact
- Battery
- DC voltage source
- AC voltage source
- Fuse
- Circuit breaker
- Ground (earth)
- Chassis ground
- Lamp
- Motor
- Generator
- Ammeter
- Voltmeter
- Wire junction
- Wires crossing
- Terminal
- Square groove weld
- V groove weld
- Bevel groove weld
- U groove weld
- J groove weld
- Flare-V groove weld
- Flare-bevel groove weld
- Double-V groove weld
- Double-bevel groove weld
- V groove with broad root face
- Fillet weld
- Double fillet weld
- Plug or slot weld
- Spot weld
- Seam weld
- Surfacing weld
- Back or backing weld
- Weld all around
- Field weld
- Backing strip
- Flush contour
- Convex contour
- Concave contour
- Reference line and arrow
- Other side weld
- Tail
Which drawing uses which symbols
- P&IDs show the process: piping, valves, equipment and the instruments that measure and control it. See also how to read a P&ID.
- Single line diagrams show the electrical power system: sources, busbars, transformers, switchgear and protection.
- Electrical schematics and circuit diagrams show how control and electronic circuits work: components, switches, relay coils and contacts, protection and wiring.
- Welding symbols on fabrication, structural and piping drawings say what weld to make, on which side of the joint, how big and how it is finished.
- Piping isometrics show one line in three dimensions, with every weld, fitting, valve and dimension needed to fabricate and install it.
On a project, every symbol on these drawings becomes a tag in the register, and every tag is built, tested and handed over. That is the work Deskely runs, from the first drawing to handover.
Frequently asked questions
Which symbol libraries are there?
P&ID symbols (92 symbols), Single line diagram symbols (34 symbols), Electrical symbols (34 symbols), Welding symbols (26 symbols), Piping isometric symbols (27 symbols). More libraries are added as they are drawn.
Which standards do the symbols follow?
Each library shows the forms of the standards used for that kind of drawing: ISA 5.1, ISO 10628, PIP PIC001, DIN and IEC 62424 for P&IDs, ANSI / IEEE 315 and IEC 60617 for electrical single line diagrams and schematics, and AWS A2.4 and ISO 2553 for welding.
Are the symbols free to use?
Yes. Every symbol was drawn by Deskely and is free to use in your own drawings, documents and training material, as SVG, PNG or in the printable PDF charts.