Overview
EN ISO 7233:2021 (adopted by CEN as EN ISO 7233:2021) specifies test methods for determining the resistance to vacuum of rubber and plastics hoses and hose assemblies. The standard defines three test methods (A, B and C) applicable to different hose nominal sizes and includes procedural requirements for apparatus, sample preparation, conditioning and test reporting. This fifth edition (2021) updates the 2016 version and explicitly includes hose assemblies and additional guidance on length change measurement in Method C.
Key topics and requirements
- Scope and methods
- Method A: for hoses of nominal size up to and including 80. Uses a smooth solid ball to detect internal deformation or obstructions.
- Method B: for hoses of nominal size greater than 80. Uses transparent airtight plates to visually inspect for delamination and blistering.
- Method C: applicable to hoses of all dimensions and may be used as an alternative to A or B; includes quantitative measurement of length and cross‑sectional change.
- Apparatus
- Vacuum pump with gauge capable of reaching and holding the specified internal pressure within 60 s and maintaining it for at least 10 min.
- Solid ball (Method A) sized at 0.9 × bore (rounded down to nearest mm).
- Two transparent airtight plates (Method B) allowing internal visual inspection and illumination.
- Specimen preparation and conditioning
- Test pieces: minimum 1 m length (clear of end fittings) where applicable.
- No testing within 24 h of manufacture; condition specimens per ISO 23529 at the appropriate temperature for at least 3 h prior to testing.
- Test procedure and measurements
- Reduce internal pressure to the product‑specified minimum test pressure within 60 s, hold ≥10 min.
- Inspect externally for collapse, irregularities, flaws.
- Methods A/B detect internal deformation and delamination; Method C requires marking lines and measuring change in length and minor axis before, during and after vacuum.
- Reporting
- Record method used, test pressure, time held, conditioning, dimensions and any signs of collapse or delamination.
Applications
- Assessing field performance of suction hoses, vacuum lines and negative‑pressure fluid transfer systems.
- Quality control and type testing during hose manufacture.
- Verifying adhesion between lining and reinforcement (delamination checks) for hard‑wall hoses.
- Specifying acceptance criteria in procurement and product standards.
Who uses this standard
- Hose and hose‑assembly manufacturers
- Test laboratories and quality engineers
- Product designers and R&D teams working on suction/vacuum applications
- Procurement and compliance officers specifying EN ISO 7233:2021 in contracts
Related standards
- ISO 1402 - Hydrostatic testing for hoses
- ISO 8330 - Hose and hose assemblies vocabulary
- ISO 23529 - Conditioning of rubber test pieces
Keywords: EN ISO 7233:2021, vacuum resistance, rubber and plastics hoses, hose assemblies, vacuum testing, delamination, Method A, Method B, Method C.
