Overview
EN ISO 6801:2021 - Rubber and plastics hoses - Determination of volumetric expansion - specifies a laboratory method to measure the volumetric expansion of rubber or plastic hoses when subjected to hydrostatic pressure. Adopted by CEN as EN ISO 6801:2021, the standard defines apparatus, calibration, test procedure, result expression and reporting requirements. It does not prescribe test-piece dimensions or test pressures (these are given in the applicable product specification).
Key topics and technical requirements
- Scope: Method for determining volumetric expansion under hydrostatic pressure; dimensions and pressures are specified elsewhere.
- Apparatus: Pressure source, pressure gauges, piping and valves with smooth bores, a vertical hose mounting, and a graduated burette for measuring displaced fluid.
- Pressure rise rates (clause 4.2):
- 0.075–0.175 MPa/s for test pressures ≤ 12.5 MPa.
- 0.35–1.0 MPa/s for higher test pressures.
- Calibration: Determine apparatus correction factor using a steel hydraulic test tube (specified dimensions in the standard). If the correction factor at 10.3 MPa exceeds 0.08 cm³, the apparatus is unsuitable.
- Procedure highlights:
- Use distilled water and remove air from the system (moving the hose can help).
- Perform three consecutive pressure cycles; collect the total volume of the three expansions in the burette.
- Repeat or discard tests if air ingress or overpressure occurs (rules provided).
- Result expression: Volumetric expansion E = (V − C) / l, reported in cm³/m (V = total 3-cycle volume, C = correction factor, l = free length).
- Test report: Must include reference to ISO 6801:2021, hose description, test-piece dimensions, test pressure, correction factor, total volume, expansion (cm³/m), percentage expansion (if required), deviations and test date.
Applications and users
- Who uses it: Hose manufacturers, independent test laboratories, R&D teams, quality control, procurement/specification engineers, and conformity/approval bodies.
- Practical uses:
- Verify that hoses meet volumetric stability requirements for dispensing precise fluid volumes.
- Quality control during production and final acceptance testing.
- Supporting product specifications, supplier qualification and performance comparisons.
- Research and development for new hose materials and designs.
- Industries: Automotive, chemical processing, fuel dispensing, medical devices (where applicable specifications cite ISO 6801), and industrial hydraulics.
Related standards
- ISO 1402 - Rubber and plastics hoses and hose assemblies - Hydrostatic testing (referenced for pressure procedures).
- ISO 8330 - Rubber and plastics hoses and hose assemblies - Vocabulary (terms and definitions used).
Keywords: EN ISO 6801:2021, volumetric expansion, rubber and plastics hoses, hydrostatic pressure, hose testing, burette, correction factor, ISO 1402.
