PD ISO TS 81346 — Industrial Systems, Installations, Equipment and Industrial Products Structuring Principles and Reference Designations (Parts 3 & 10)

🏭 PD ISO/TS 81346 is a BSI Published Document implementing the ISO/IEC 81346 reference designation series for industrial systems, installations, equipment and industrial products. A reference designation is a unique numbering system assigned to objects (equipment, components, functions, locations, etc.) in an engineering project, forming the basis for data management throughout the plant design, construction, operation and modification life cycle. Part 3 specifies the application rules for a reference designation system and Part 10 specifies its application to power plants, both prepared by BSI Technical Committee TDW/4 (technical product realization).

1. Scope and General Framework 📌

The PD ISO/TS 81346 series applies to structuring and reference designations for industrial systems, installations, equipment and industrial products. Part 3 (application rules) specifies how to construct a reference designation system based on object classification and “aspects”, giving designation structure, separators, letter codes and documentation requirements. Part 10 (power plants) applies the general rules to power plant objects, specifying classification, designation assignment and documentation of objects inside and outside the plant. Part 3 supersedes the withdrawn DD ISO/TS 16952-1:2007.

2. Structuring Principles and Designation Construction 🔧

The core elements of the reference designation system include:

• Object classification and aspect: objects can be described by functional aspects (e.g. pumping, heating), product aspects (e.g. a specific pump model) and location aspects (e.g. building, room); a designation may combine several aspects.
• Prefixes and separators: use “=” (function/aspect), “-” (product) and “+” (location) as prefixes and separators to distinguish aspects.
• Letter codes: assign letter codes to functions and products based on an object classification table (e.g. ISO 81346-2).
• Documentation and number management: specify representation of designations in drawings, documents and data models, and management of uniqueness and traceability.

Through these elements, engineering objects can be consistently linked between design data (e.g. P&ID, electrical diagrams, instrument index) and operation & maintenance data (asset register, work permits, maintenance records).

3. Power Plant Application (Part 10) 🔩

Part 10 applies the 81346 general principles to power plants, covering:

• Power plant object classification: classification of boiler, turbine, generator, feedwater system, cooling water system, electrical system, instrumentation and control system objects.
• Inside/outside distinction: coordination of designations for objects inside the plant boundary and outside (e.g. grid connection).
• Multi-discipline collaboration: project-level unified management of mechanical, electrical, instrumentation and civil designations.
• Engineering documentation and data handover: supporting structured handover of design, as-built and O&M data between EPC contractors and owners.

Power plant projects involve many participants over a long cycle; a unified reference designation system is important for reducing interface errors and supporting digital handover (e.g. plant information models).

4. Engineering Practice Essentials 🔍

• 🔧 Plan at project start: establish designation rules and number allocation tables early in the project to avoid rework.
• 🔩 Cross-discipline unification: mechanical, electrical, instrumentation and civil use the same structuring principles to ensure interface consistency.
• 📊 Data-driven operation: use the reference designation as the primary key in the asset register and work-permit management, connecting design and operation.
• 🔄 Digital handover: organise as-built data and BIM/plant information models by standard designations to support intelligent operation.

4b. Implementation and Governance 🔧

Introducing a reference designation system is as much an organisational task as a technical one. A project should appoint a single designation authority that owns the numbering rules, the object classification tables and the number allocation register, so that design, procurement, construction and operation teams all draw on the same source. Changes should be managed through a change-control process, and the designation register should be kept in a form that supports automated export to data models and plant information systems.

The letters used in the designation, the separators and the aspect prefixes should be documented in a project-specific designation standard that references ISO 81346 but adapts it to the plant type. Where an existing plant uses a legacy numbering scheme, the retrofit should map the legacy designations to the new system and publish a conversion table rather than renumbering equipment in the field. For cross-discipline coordination, mechanical, electrical, instrumentation and civil disciplines should agree on the shared functional classification before detailed design starts, so that the same object receives one consistent functional designation across all drawings.

In summary, a reference designation system is a governance instrument that ties together the design data, the asset register and the operating records. Used consistently from project start through operation and modification, it reduces interface errors, supports digital handover and enables reliable asset and maintenance management.

5. Frequently Asked Questions ❓