ISO 6802:2018

Overview

ISO 6802:2018 - "Rubber or plastics hoses and hose assemblies - Hydraulic impulse test with flexing" specifies a standardized method for impulse testing hydraulic rubber or plastic hose assemblies while subjecting them to flexing motion. The procedure covers both high-pressure (> 3 MPa) and low-pressure (1.5 MPa to 3 MPa) impulse regimes and is intended for hose assemblies that experience pulsating pressures and movement in service. An optional cool-down leakage test is included (Annex A). Note: impulse tests without flexing are covered by ISO 6803.

Key topics and technical requirements

• Test scope: Applies to complete hose assemblies with fittings; typically four unaged samples unless otherwise specified.
• Pressure ranges: High-pressure > 3 MPa; low-pressure 1.5–3 MPa.
• Flexing methods: Two apparatus layouts - a revolving manifold (Method 1) or a horizontally sliding manifold (Method 2). The movable manifold remains parallel to the stationary manifold.
• Flex geometry:
  • Distance from stationary centreline: l = 1.75·r + d_ext (±2 mm)
  • Free hose length between couplings: L = 4.14·r + 3.57·d_ext (±15 mm)
  • r = minimum bend radius; d_ext = external hose diameter
• Cycle relationship: Movable manifold cycles per minute = 34–38% of impulse cycles per minute (flex cycles proportional to impulse cycles).
• Test fluid: Recommend kinematic viscosity ISO VG 32–100 (32–100 mm²/s at 40 °C, per ISO 3448). Other fluids may be agreed between manufacturer and customer.
• Failure and leakage: Leakage less than Class 4 (ISO/TR 11340) is not a failure. Failures near fittings (within 25 mm) are recorded as fitting failures.
• Optional cool-down leakage test: Cool to ~30 °C (±10 °C) at 40% ±10% and 90% ±10% of cycles, then resume and observe leakage for 1 000 cycles.
• Reporting: Test report must record test method, temperature, pressure, fluid, impulse rate, flex frequency, cycles to failure or completion, failure mode/position, fittings details, and whether cool-down test was used.

Applications and users

• Hydraulic hose and hose assembly manufacturers - design verification and product qualification.
• Test laboratories and third‑party certification bodies - compliance testing and quality assurance.
• OEMs and system integrators - selection and validation of hoses used in mobile and industrial hydraulic systems subject to pulsation and movement.
• Maintenance and reliability engineers - failure analysis, lifecycle expectations, and procurement specifications.

Related standards

• ISO 6803 - Hydraulic-pressure impulse test without flexing
• ISO/TR 11340 - External leakage classification for hydraulic systems
• ISO 3448 - Viscosity classification for test fluids
• ISO 8330 - Hoses and hose assemblies vocabulary

Keywords: ISO 6802:2018, hydraulic impulse test with flexing, rubber hoses, plastics hoses, hose assemblies, flex test rig, cool down leakage test, ISO VG 32-100.