Overview
ISO 5941:1979 - Compressors, pneumatic tools and machines - Preferred pressures - defines a set of preferred (reference) effective (gauge) pressures in bars to be used when presenting performance data for pneumatic equipment. The standard helps align rated pressures for compressors and design pressures for pneumatic tools and machines, and it advises that components for compressed air systems be designed to meet these standardized pressures. The document covers a practical pressure range used in industry and recognizes some de facto nominal pressures that deviate from the ideal series.
Key topics and requirements
- Preferred and rated pressures: Specifies preferred rated pressures for compressors and preferred design pressures for pneumatic tools and machines (pressures expressed as gauge pressure in bars).
- Pressure range: Addresses pressures across the industry range (examples in the standard span from fractions of a bar up to several hundred bars; the document references values between about 0.4 and 400 bar).
- Industry deviations: Accepts certain widely used nominal values (for example, 7 bar ≈ 100 lbf/in² gauge and 18 bar ≈ 250 lbf/in² gauge) and includes one non-preferred value (12.5 bar) taken from related ISO series when needed.
- Application-specific examples: Associates preferred pressures with typical uses (e.g., spray-painting, rock drills, air motors, sandblasting), helping manufacturers and specifiers choose appropriate design or rated pressures.
- Definitions and testing guidance: Clarifies terms such as “rated pressure” (compressors) and “design pressure” (tools/machines), and points to testing standards (for example ISO 2787 for pneumatic tool acceptance tests).
Applications and users
ISO 5941:1979 is practical for:
- Compressor and pneumatic-tool manufacturers specifying rated or design pressures.
- System designers and engineers who size compressed-air components and receivers.
- Test laboratories and quality teams presenting or verifying performance data.
- Procurement and maintenance teams that standardize spare parts and system components.
- Specification writers and standards committees seeking harmonized pressure levels for product data sheets.
By using ISO 5941 preferred pressures, organizations improve interoperability, simplify product selection, and reduce the need for custom pressure ratings.
Related standards
- ISO 2944 - Fluid power systems and components: nominal pressures (preferred numbers series R5/R10).
- ISO 2787 - Rotary and percussive pneumatic tool acceptance tests.
Keywords: ISO 5941:1979, preferred pressures, compressors, pneumatic tools, design pressure, rated pressure, gauge pressure, compressed air systems, pneumatic machines.
