Overview
EN ISO 9908:1997/A1:2011 is a minor amendment to the European adoption of ISO 9908:1993, covering technical specifications for centrifugal pumps - Class III. Issued by CEN in April 2011, this amendment primarily updates normative references and clarifies which hydraulic test standard and acceptance class apply when assessing Class III centrifugal pumps. The amendment preserves the original standard’s content while aligning test and NPSH references to the revised ISO test series.
Key topics and requirements
- Scope: Applies to technical specifications for Class III centrifugal pumps (ICS 23.080).
- Normative reference updates:
- NPSHR basis: Net positive suction head required (NPSHR) values are now to be based on cold water as specified in ISO 9906, instead of the older ISO references.
- Hydraulic performance tests: Where a hydraulic performance test is required, it shall be conducted in accordance with ISO 9906 Class 2 for clean cold water.
- Editorial changes: Minor table footnote renumbering and removal of an ISO 2372 footnote; no technical content of EN ISO 9908:1997 was altered beyond reference alignment.
Practical applications
- Manufacturers and designers: Use the amended standard when specifying performance acceptance criteria, reporting NPSHR, and ensuring pump designs meet Class III requirements referenced to ISO 9906 test methods.
- Test laboratories and QA teams: Apply ISO 9906 Class 2 procedures for performance testing of Class III centrifugal pumps and base NPSHR on cold-water measurements per ISO 9906.
- Procurement and specifications: Include EN ISO 9908:1997/A1:2011 references in tender documents and contracts to ensure consistent acceptance testing and performance verification across suppliers and countries.
- Compliance officers and standards managers: Ensure national adoption and withdrawal of conflicting national standards per CEN timelines, and note potential patent-right considerations called out in the foreword.
Related standards
- ISO 9906 (Rotodynamic pumps - Hydraulic performance acceptance tests - Grades 1,2,3) - primary test-method reference after this amendment.
- Historical references replaced: ISO 2548 and ISO 3555 (now superseded in the context of EN ISO 9908 by ISO 9906).
This amendment is primarily administrative and alignment-focused, improving consistency between EN ISO 9908 and the current ISO test methodology for rotodynamic pumps. Keywords: EN ISO 9908:1997/A1:2011, ISO 9908, centrifugal pumps, Class III, ISO 9906, NPSHR, hydraulic performance tests, CEN.
