ISO 5198:1987

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.