ISO 7840:2021

Overview

ISO 7840:2021 - Small craft - Fire-resistant fuel hoses - specifies requirements and physical test methods for fire-resistant fuel hoses used in permanently installed fuel systems on small craft (≤ 24 m hull length). It covers hoses for petrol (including petrol blended with ethanol) and diesel (including diesel blended with FAME) designed for working pressures up to 0.34 MPa (hoses ≤ 10 mm inner diameter) and 0.25 MPa (hoses up to 63 mm inner diameter). The standard excludes hoses entirely inside the splash well connected directly to outboard engines.

Key Topics and Requirements

• Scope and applicability: Hoses for permanently installed small‑craft fuel systems; not for splash‑well outboard connections.
• Working pressures & sizes: Inner diameter tolerances defined; pressure limits as above.
• Preconditioning & test fluids:
  • Petrol test fluid: 90% ISO‑1817 liquid C + 10% ethanol.
  • Diesel test fluid: 90% ISO‑1817 liquid F + 10% FAME (EN 14214).
  • Typical preconditioning: 40 days at 40 °C (28 days permitted for Type 15 low‑permeation hoses).
• Physical tests on finished hose (selection):
  • Bursting pressure: ≥ 1.4 MPa for ≤10 mm ID; ≥ 1.0 MPa for >10 mm ID.
  • Vacuum‑collapse: sphere passage under specified vacuum (80 kPa for d ≤10 mm; 35 kPa for 10