Overview
ISO 11759:1999 specifies requirements for flexible rubber hoses and hose assemblies used to dispense liquefied petroleum gases (LPGs) from dispensing equipment to motor vehicles. Intended for permanent “wet” service (filled with liquid), the standard covers hoses that operate in the temperature range –40 °C to +60 °C with a maximum working pressure of 20 bar (2 MPa). It defines materials, construction, dimensions, performance tests and marking needed to ensure safe, reliable LPG transfer.
Key Topics and Requirements
- Scope & use: Hoses for metered transfer of LPG from dispensers to vehicles; designed for continuous liquid fill.
- Classification:
- Type 1 - textile reinforcement with a metallic bonding element (braided bonding wires); suitable for reeling or single-loop draping.
- Type 2 - fine wire reinforcement; suitable for reeling or single-loop draping.
- Materials & construction: Smooth fuel-resistant rubber lining, one or more reinforcement layers (textile or corrosion‑resistant wire), electrically conductive element (Type 1), abrasion- and weather‑resistant rubber cover. Covers may be pricked to relieve trapped gas.
- Pressure ratings (ISO 1402):
- Maximum working pressure: 20 bar
- Proof test pressure: 40 bar
- Minimum burst pressure: 100 bar
- Dimensions & tolerances: Nominal bores and permitted diameter tolerances (16, 19, 20, 25 mm) and minimum lining/cover thickness (lining ≥ 1.6 mm; cover ≥ 1.0 mm).
- Physical & performance tests: Tensile strength, elongation, accelerated ageing, liquid resistance, hydrostatic proof and burst, volumetric expansion, flexibility (ambient and low temperature), ozone and abrasion resistance, adhesion, electrical continuity/resistance, LPG permeability, and an Annex A reverse-bending flex test.
- Marking & traceability: Durable marking at least every metre with manufacturer ID, ISO number, hose type, nominal bore, max working pressure and manufacturing/assembly date.
- Testing frequency: Approval (full) tests and production/routine tests defined; many performance tests are required as approval tests while dimensional and proof tests are required for each production length.
Applications and Users
- Primary users: Hose manufacturers, LPG dispenser OEMs, fuel station operators, inspection and testing laboratories, procurement and quality assurance teams.
- Applications: Vehicle refuelling hoses at LPG service stations, dispenser system assemblies, and replacement hose assemblies where compliance with safety, pressure and low-temperature performance is required.
- Practical value: Ensures compatibility with LPG fluids, electrical continuity for safety, mechanical durability for reeling and repeated flexing, and traceability for maintenance and regulatory compliance.
Related Standards
Normative references cited include ISO 1402 (hydrostatic testing), ISO 37 (tensile tests), ISO 188 (accelerated ageing), ISO 4080 (gas permeability), ISO 1746 (bending/flexibility) and ISO 8031 (electrical resistance), among others - useful for implementing full test programs and quality systems.