Overview
ISO 14084-2:2015 - Process diagrams for power plants: Part 2: Graphical symbols specifies standardized graphical symbols and guidance for creating new symbol examples used in process diagrams for power plants. Published April 2015, this part is a collective application of the ISO 14617 series and clarifies representation rules (symbol size, registration numbers, table representation and legends) so engineers and technical authors can produce consistent, unambiguous diagrams for design, construction, operation and maintenance.
Key topics and technical requirements
ISO 14084-2:2015 covers the visual language and structuring rules for power plant process diagrams, including:
- General rules: symbol size, representation styles, and guidelines for creating new symbols.
- Structuring: overall diagram structure, registration numbers, and legend/table conventions.
- Connections: fluid and mechanical connections, direction, branching, crossings, pipeline joints and accessories.
- Fluid flow control: valves (on-off, non‑return, control, safety), dampers, and related safety devices.
- Actuators: manual, mechanical and automatic actuators plus supplementary symbols.
- Fluid transport and energy transfer: pumps, fans, compressors, heat exchangers, cooling towers and mixing devices.
- Fluid processing & storage: separation devices, adsorption/catalysis, mixing, storage tanks and energy storage.
- Material handling and processing: conveyors, feeders, crushers, mills and handling equipment.
- Thermal energy systems and machines: boilers, combustion systems, turbines, engines and electrical machines.
- Mechanical components: shafts, bearings, gears, couplings and brakes.
The standard also indicates where domain‑specific symbol sets apply-fluid power symbols are covered by ISO 1219‑1 and electrotechnical symbols by IEC 60617.
Practical applications
ISO 14084-2:2015 is used to:
- Create consistent process diagrams for power plant design packages and technical documentation.
- Build CAD and symbol libraries for engineering software and drawing templates.
- Standardize handover documents for construction, commissioning and maintenance.
- Support regulatory submissions, safety reviews and operator training with unambiguous diagrams.
Who should use it
- Power plant process, mechanical and control systems engineers
- Piping and instrumentation diagram (process diagram) authors and CAD librarians
- Technical illustrators, documentation specialists and training developers
- Vendors supplying equipment data sheets or CAD blocks for power plant projects
- Regulators and safety auditors reviewing documentation consistency
Related standards
- ISO 14617 series - graphical symbols for diagrams (base application)
- ISO 1219‑1 - graphical symbols for fluid power systems
- IEC 60617 - graphical symbols for electrotechnical diagrams
Using ISO 14084-2:2015 helps ensure clear, interoperable process diagrams across engineering teams and software tools, improving communication, safety and lifecycle efficiency in power plant projects.
