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<d≤25 mm).
  • Volume change / swelling: tube ≤ 35% volume increase; cover up to 120% if different material.
  • Mass reduction: tube mass loss ≤ 8% after conditioning.
  • Fire resistance: method specified in Annex A.
  • Fuel permeation (Annex B): classification into Type 1, Type 2, and Type 15 based on permeation rates (Type 15 ≤ 15 g/m²·24 h).
  • Cold‑flex, abrasion, ozone, dry heat and oil resistance, and adhesion tests with defined acceptance criteria.
• Marking: Hoses must be marked per Clause 7, including permeation type and intended fuels.

Applications and Users

ISO 7840:2021 is used by:

• Hose manufacturers designing and certifying fire‑resistant marine fuel hoses.
• Boat builders, naval architects and systems integrators specifying compliant hoses for permanently installed fuel systems.
• Test laboratories and certification bodies performing conformity and type testing.
• Maritime regulators, surveyors and fleet maintenance teams to ensure safety and reduce vapor emissions and fire risk. Practical benefits include improved fire safety, reduced fuel vapour permeation, and harmonized acceptance criteria across international markets.

Related Standards

• ISO 8469:2021 - Non‑fire‑resistant fuel hoses for small craft.
• ISO 10088:2013 - Permanently installed fuel systems (system requirements).
• Normative test references: ISO 1402, ISO 1817, ISO 7233, ISO 7326 and EN 14214 (FAME specification).

Keywords: ISO 7840:2021, fire‑resistant fuel hoses, small craft, marine fuel hoses, fuel permeation, bursting pressure, fire resistance test, petrol ethanol, diesel FAME, hose testing, marine safety.