Use this compressor symbols legend CAD resource as a quick visual reference when preparing P&ID drawings, utility schematics, and process documentation. The downloadable DWG groups common compressor symbols and related equipment marks so designers can compare symbol styles while building or reviewing a drawing.
It is especially useful when a project includes several compressor types, compressed-air equipment, silencers, or generic equipment blocks. Before issuing a drawing, compare the selected symbol with the project legend and confirm that tags, line connections, flow direction, and equipment descriptions are documented consistently.
This Compressor Symbols Legend CAD sheet is a clean reference for P&ID and process schematics. It includes common compressor and related equipment symbols used in utilities, HVAC/process plants, and industrial piping diagrams—so your drawings stay consistent and easy to review.
The legend typically includes symbols for:
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General compressor (multiple symbol styles)
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Centrifugal compressor (several variations)
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Rotary compressor (and rotary compressor with silencers)
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Screw compressor
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Piston compressor
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Axial compressor
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Turbo compressor
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Diaphragm compressor
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Liquid ring compressor / vacuum pump style symbol
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Air compressor and AC air compressor
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Compressor silencers
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“Selectable compressor” symbol for generic equipment blocks
Use this CAD legend for:
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P&ID drawings, utility schematics, and compressed air systems
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Standardizing symbols across multi-discipline projects
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Drafting libraries and quick QA checks for symbol consistency
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Faster documentation for mechanical/process teams
How to use the compressor CAD legend
A symbol legend supports drafting consistency; it does not by itself define equipment performance, process conditions, or the design requirements for a compressor package. Use the symbol to identify the equipment category on the drawing, then refer to the project equipment list, process information, and applicable drafting conventions for the remaining details.
Compressor symbol groups in the DWG
| Symbol group | Drafting purpose |
|---|---|
| General compressor | Use when the drawing requires a general compressor representation or when the specific machine type is not yet selected. |
| Centrifugal, rotary, screw, piston, axial, and turbo compressors | Use the equipment-specific symbol when the compressor type needs to be distinguished on the P&ID or process schematic. |
| Diaphragm and liquid ring compressor symbols | Use for specialized compressor or vacuum-service representations identified by the project documentation. |
| Air and AC air compressors | Use in compressed-air and utility documentation where the air-compressor function is important to the diagram. |
| Silencers and selectable compressor symbols | Use to show related compressor equipment or a generic equipment block when the drawing requires a flexible symbol choice. |
Drafting and review checklist
- Confirm that the compressor symbol matches the equipment description and tag.
- Keep the symbol legible at the drawing scale and aligned with connected piping.
- Use the same symbol convention throughout the drawing set unless the project legend states otherwise.
- Check whether silencers, air-service equipment, or other related items need separate identification.
- Use the DWG as a drafting reference, then complete the drawing with project-specific tags, notes, valves, instruments, and line data.
For related reference work, pair this resource with your project's P&ID symbols, piping terminology, fitting symbols, and flange reference pages. Those topics help connect equipment identification with the piping and documentation details shown around the compressor.
Compressor symbols CAD FAQ
What is included in this compressor symbols legend?
The DWG includes general, centrifugal, rotary, screw, piston, axial, turbo, diaphragm, liquid ring, air, and AC air compressor symbols. It also includes compressor silencers and a selectable compressor symbol for generic equipment blocks.
Can this legend be used for P&ID drawings?
Yes. The source sheet is intended as a reference for P&ID drawings, utility schematics, compressed-air systems, and related process documentation. Confirm the final symbol convention against the requirements of the specific project.
Does the symbol identify compressor capacity or operating conditions?
No. A symbol identifies the equipment representation on the drawing. Capacity, pressure, temperature, materials, controls, and other technical information must come from the applicable equipment and process documentation.
When should I use a selectable compressor symbol?
Use the selectable compressor symbol when a generic compressor equipment block is needed or when the specific compressor type has not been represented by a more appropriate symbol in the drawing.
Are compressor silencers shown separately?
Yes. The legend includes compressor silencer symbols so related equipment can be represented where the project drawing requires it.