Overview
EN ISO 8308:2015 (ISO 8308:2015) - "Rubber and plastics hoses and tubing - Determination of transmission of liquids through hose and tubing walls" - specifies laboratory methods to measure how liquids are transmitted (by permeation and evaporation) through hose and tubing walls. The standard defines two test methods: Method A, a comparative, pressure-based test that simulates working conditions for all hose/tubing sizes; and Method B, a gravimetric, pressureless test for hose and tubing up to 16 mm inside diameter.
Key topics and requirements
- Two test methods
- Method A: Uses a pressurised apparatus (nitrogen source, regulator, safety valve) where test pieces (e.g., a hose assembly with 250 mm free length or tubing samples) are charged with test liquid. Measurements are taken at 24 h intervals until a steady-state evaporation rate is reached. Test pressure: 50 kPa ± 5 kPa (gauge). Result expressed as steady-state evaporation in mL per m² per hour.
- Method B: A pressureless reservoir is partly filled and attached to a length of hose/tubing (other end plugged). Assembly is weighed initially and daily for eight days. The result is the maximum mass loss in any 24 h period per unit inside surface area. The method accounts for permeation and evaporation and reduces selective permeation by daily agitation.
- Test pieces and sampling: Three test pieces required for Method A; defined internal free length and inside diameter measured per referenced standards.
- Test conditions: Standard test temperatures are (23 ± 2) °C or (27 ± 2) °C (ISO 23529). Test liquid is specified by the relevant product standard.
- Safety: Method A warns about hazardous vapours - tests must be performed in well-ventilated areas and apparatus must include safety provisions (safety valve, shield).
- Reporting: Test report must identify the hose/tubing, reference the standard, specify method used, test liquid, conditions and results.
Applications
- Assessing permeation and evaporation performance of rubber and plastic hoses and tubing used for fuels, solvents, hydraulic fluids, chemicals and other liquids.
- Comparative material and construction testing during product development and material selection.
- Quality control and type testing for manufacturers and test laboratories.
- Supplying objective permeability data for procurement specifications, regulatory compliance and safety assessments.
Who uses this standard
- Hose and tubing manufacturers
- Independent test laboratories and certified quality-control facilities
- R&D and materials engineers evaluating barrier performance
- Purchasing and compliance teams specifying hose performance
- Standards bodies and regulatory authorities
Related standards
- ISO 4671 - measurement of hose dimensions and lengths
- ISO 4788 - graduated measuring cylinders (laboratory glassware)
- ISO 23529 - specimen preparation and conditioning for rubber tests
Keywords: EN ISO 8308:2015, ISO 8308:2015, rubber and plastics hoses, tubing, transmission of liquids, permeation, evaporation, method A, method B, hose testing, permeability.
