Overview
ISO 5198:1987 - "Centrifugal, mixed flow and axial pumps - Code for hydraulic performance tests - Precision grade" is an International Standard that establishes procedures and definitions for precision-class (former class A) hydraulic performance testing of pumps. It is the first in a set of pump-testing standards and is intended for laboratory-level, high-accuracy measurements used primarily in research, development and scientific investigations. The standard defines terms and quantities, specifies general test requirements and details measurement methods without prescribing constructional tolerances.
Key topics
- Scope and purpose
- Precision-class testing for centrifugal, mixed-flow and axial pumps.
- Applies to pumps tested on bench or site (where installation permits).
- Does not define constructional tolerances or contractual acceptance limits.
- Definitions and statistical concepts
- Formal definitions for measuring systems, instruments, steady/unsteady processes, mean/variance, fluctuations, response time and readings.
- Emphasis on steady operating conditions and appropriate integration periods.
- Measurement methods (section summaries)
- Flow measurement - recommended methods and references to established flow-measurement techniques.
- Head and speed - procedures for accurate head and rotational-speed measurement.
- Power input and efficiency - methods for power measurement and for efficiency determination using the thermodynamic method.
- Cavitation tests - procedures for cavitation characterization and special cavitation test annexes.
- Uncertainty and data handling
- Annexes cover estimation and analysis of uncertainties, comparison of test results with specified duties, and thermodynamic properties of water relevant to efficiency measurement.
Applications
Who uses ISO 5198:1987 and why:
- R&D engineers and test laboratories - to produce repeatable, high-precision pump performance curves for model development and validation.
- Manufacturers and designers - for benchmarking pump designs and verifying performance in controlled conditions.
- Standards and metrology specialists - to define measurement protocols, compute uncertainties and report results consistently.
- Buyers and specifiers - as a reference when contracting precision tests (with contractual acceptance criteria agreed separately).
Practical uses include high-accuracy performance verification, cavitation assessment, efficiency mapping using thermodynamic methods, and laboratory comparison of pump prototypes.
Related standards
Relevant documents and cross-references cited in ISO 5198:1987:
- ISO 2548, ISO 3555 (other pump test codes / acceptance classes)
- ISO 5167, ISO 5168 (flow measurement and uncertainty)
- ISO 3534 (statistics - vocabulary and symbols)
- IEC publications for storage-pump acceptance testing (e.g., IEC 198, IEC 497)
- Other ISO methods for flow measurement and tracer techniques
ISO 5198:1987 is essential when extremely precise hydraulic performance data are required; contractual interpretation of results (acceptance limits) must be agreed separately between parties.