Overview
EN ISO 5198:1998 (ISO 5198:1987) - Centrifugal, mixed flow and axial pumps - Code for hydraulic performance tests - Precision class - is the precision-class test code for hydraulic performance measurement of pumps. It is the first in a series of pump test standards and defines the terms, quantities and general requirements for high-accuracy laboratory and bench tests. The standard addresses precision-class (former Class A) testing used mainly for research, development and scientific purposes. It does not prescribe constructional tolerances or contractual acceptance limits.
Key topics and technical requirements
EN ISO 5198 covers procedures and measurement methods required to obtain highly accurate hydraulic performance data for centrifugal, mixed-flow and axial pumps. Major technical topics include:
- Definitions and symbols used in precision pump testing (statistics and signal concepts such as mean, variance, steadiness).
- Specified duty and how to select operating points for tests.
- General test requirements including steadiness criteria and test arrangement (pump alone or pump with fittings).
- Measurement methods for:
- Rate of flow (flow measurement techniques, closed- and open-channel methods referenced)
- Head measurement
- Speed of rotation
- Power input
- Pump efficiency by the thermodynamic method
- Cavitation tests and other hydraulic phenomena relevant to performance evaluation.
- Assessment of measurement uncertainty, data analysis and comparison with specified duty (see Annexes covering uncertainty estimation, efficiency thermodynamics, cavitation, friction losses).
- Emphasis on steady operating conditions, statistical treatment of fluctuations and accurate instrumentation/reading practices.
Practical applications
This standard is used when high-precision hydraulic performance data are required, such as:
- Research and development of pump hydraulics and performance curves
- Laboratory testing of prototypes and scale models
- Benchmarking and verification of pump performance for high-tech or critical industrial applications
- Detailed cavitation and efficiency studies using thermodynamic methods
Note: precision-class testing typically requires controlled test beds or mutually agreed laboratories. It is more costly and may not be practical for routine site acceptance tests.
Who should use this standard
- Pump test laboratories and research institutions
- Pump manufacturers and design engineers
- R&D teams working on centrifugal, mixed-flow and axial pumps
- Purchasers and specifiers drafting contractual test and acceptance criteria for precision testing
Related standards
Standards referenced for complementary or engineering-class testing include:
- ISO 3555 (acceptance tests - Class B / engineering class I)
- ISO 2548 (acceptance tests - Class C / engineering class II)
- ISO 5167, ISO 5168, and other flow-measurement and uncertainty standards
Keywords: EN ISO 5198, ISO 5198, centrifugal pumps, mixed flow pumps, axial pumps, hydraulic performance tests, precision class, pump testing, cavitation tests, flow measurement, measurement uncertainty.