ISO/TR 12942:2012

Overview

ISO/TR 12942:2012 - "Compressors - Classification - Complementary information to ISO 5390" is an informative Technical Report from ISO/TC 118 that provides a structured, multi‑dimensional classification and vocabulary for modern compressor types. It complements ISO 5390 by giving definitions, design- and functional‑class schemata, and guidance on term usage in technical specifications, manufacturer literature, patents, education, testing, data systems and market statistics. As a Technical Report, it is informative (not normative) and intended to support consistent identification and comparison of compressor equipment.

Key Topics

• Design classes - Hierarchy and preferred terms for compressor design concepts (e.g., compressor machine vs compressor apparatus) and subtypes.
• Operation principles - Classification by operating principle: dynamic (turbocompressors), positive‑displacement, combined machines, and several apparatus types (ejectors, thermo‑compressors, adsorption, acoustical, pressure‑shock, liquid‑column, etc.).
• Turbo and positive‑displacement details - Subclasses such as radial/centrifugal turbo compressors and multi‑shaft, casing, cooling and flow‑number distinctions for turbo designs. Positive‑displacement definitions cover cyclic chamber compression and moving members.
• Functional classes - Terms and definitions for basic and derivative functional classes to ensure consistent specification of mobility, lubrication (oil‑free vs oil‑lubricated), cooling method, driver type, and service‑duty roles.
• Aggregated equipment - Classification of packaged compressor plants, driver‑compressor assemblies, geared configurations and service‑duty classes for plants and factory‑assembled units.
• Guidance materials - Annex A contains explanatory notes and methodical approaches for applying the classification.

Applications and Who Uses It

ISO/TR 12942:2012 is useful for:

• Manufacturers and designers - to label products, prepare datasheets and design documentation using standardized terminology.
• Specifiers and purchasers - to write unambiguous technical and contractual specifications and compare compressor alternatives on equivalent functional and capacity classes.
• Engineers and maintenance teams - for service, testing, safety and maintenance instructions that rely on consistent class definitions.
• Standards developers and regulators - to harmonize terminology across related standards and codes.
• - for accurate information searches, patent classification, market surveys and training materials.