Overview
ISO 14617-1:2005, "Graphical symbols for diagrams - Part 1: General information and indexes" is the introductory part of the ISO 14617 series. It defines how the library of harmonized graphical symbols for technical diagrams is organized and used. The standard explains the creation and use of registration numbers for symbols, rules for presentation and application of symbols in diagrams (overview, flow and circuit diagrams), and supplies three searchable indexes: an alphabetical index, a registration-number index, and a cross-reference index to related ISO/IEC standards.
Key topics and technical requirements
- Registration numbers: Every graphical symbol is given a unique, persistent registration number. Changes to a symbol are handled by adding suffix characters or issuing a new number when substantially changed.
- Application rules and examples: Rules (prefixed R) and examples (prefixed X) guide composition of composite symbols and illustrate correct usage.
- Presentation rules: Symbols follow dimensional and layout rules derived from ISO 81714-1 (module size M = 2.5 mm; small symbols may be shown at 200% with preserved line width; auxiliary grid uses 0.25 M).
- Forms and variants: Multiple forms (Form 1, Form 2, etc.) or variants of a symbol may exist to convey differing amounts of information or to suit different diagram layouts (horizontal/vertical, feedback lines).
- Same-shape symbols: Symbols that share the same shape but have different meanings receive distinct registration numbers; context or supplementary information is used to disambiguate in diagrams.
- Auxiliary lines and lettering: Auxiliary (dotted) lines indicate placement or connecting locations but are not part of the symbol. Lettering conventions are referenced to ISO 81714-1.
Practical applications and users
ISO 14617-1 is essential for anyone producing or consuming standardized technical diagrams:
- Technical authors and documentation specialists creating assembly, process or installation diagrams.
- Engineers and designers in process plants, HVAC, mechanical systems, fluid power and instrumentation.
- CAD librarians and CAD users who manage symbol libraries - CAD systems can reference symbols by registration number for unambiguous retrieval.
- Standards committees and system integrators aligning multi-disciplinary documents across ISO/IEC standards.
Benefits include improved clarity, language-independent communication, consistent diagramming practice, and easier cross-referencing between standards and CAD libraries.
Related standards
- Normative reference: ISO 81714-1:1999 (Design of graphical symbols - basic rules).
- ISO 14617 series (Parts 2–15) covers symbol sets for general application, connections, actuators, valves, pumps, measurement and control, heat transfer, material processing, installation diagrams, etc., with ISO 14617-1 providing the master index and introductory rules.
