Overview
ISO 21360-3:2019 is an ISO standard in the field of vacuum technology that defines standardized methods for measuring performance of mechanical booster vacuum pumps. Part 3 of the ISO 21360 series focuses on the specific parameters that distinguish mechanical boosters from other vacuum pumps, ensuring that measurements made by manufacturers and test laboratories are comparable and reproducible.
Key parameters defined and measured include:
- Maximum tolerable pressure difference (Δpmax) - the largest continuous pressure difference the booster can withstand without damage.
- Effective compression ratio (Keff) - the ratio of backing pressure to inlet pressure during operation.
- Compression ratio with zero throughput (K0) - compression at zero gas throughput.
- Overflow valve pressure difference (Δp1) - the pressure difference at which the booster’s overflow/safety valve opens.
Key Topics and Requirements
- Scope and applicability: Applies to mechanical booster vacuum pumps used in medium or rough vacuum applications, including gas-cooled boosters and cascaded booster systems.
- Measurement conditions: Tests use dry gas (typical relative humidity ≤ 65%), correct cooling and motor speed (manufacturer’s specifications; motor speed within ±3% of rated), and stable backing pump operation.
- Experimental setup: Includes a clean test dome, buffer volume on the backing line, calibrated vacuum gauges and traceable instruments. Measurement devices must be traceable to national standards or absolute instruments and have appropriate calibration certificates.
- Test methods and reporting: Detailed procedures for measuring Δpmax, Keff, K0 and Δp1 are given, along with requirements for evaluating measurement uncertainty and producing standardized test reports.
- Quality controls: Leak tightness of the test rig and gauge calibration (per referenced standards) are required to ensure valid results; measurement uncertainty guidance is provided in an informative annex.
Applications and Who Uses This Standard
ISO 21360-3:2019 is essential for:
- Vacuum pump manufacturers - to publish comparable performance data and validate designs.
- Independent test laboratories and quality assurance teams - to certify pump performance using consistent measurement methods.
- System integrators and R&D engineers - to size backing pumps, design cascaded booster systems, and optimize vacuum system throughput.
- Procurement and specifications writers - to compare vendor datasheets and specify verified performance metrics for medium/rough vacuum applications.
Using this standard helps ensure reliable performance claims, safer operation (via valve pressure testing) and interoperable vacuum system design.
Related Standards
Keywords: ISO 21360-3:2019, vacuum technology, mechanical booster vacuum pumps, Δpmax, Keff, compression ratio, overflow valve pressure, vacuum pump performance measurement.