ISO 8066-4:2023

Overview

ISO 8066-4:2023 specifies requirements for rubber and plastics hoses and hose assemblies used in automotive air-conditioning systems carrying gaseous Refrigerant R1234yf (tetrafluoropropene). This part targets low vibration transmission hose assemblies (suction/low-pressure applications) designed to reduce vibration transfer from the engine bay to the cabin. Operational temperature range is −40 °C to +80 °C. Because hose performance is tightly linked to the coupling, the standard requires that the coupling intended for service be used during testing.

Key topics and technical requirements

• Construction and materials
  • Seamless synthetic rubber inner tube, textile reinforcement (yarn/cord/fabric) and heat- & ozone-resistant synthetic rubber outer cover.
• Pressure class
  • Specified as low-pressure suction application; working pressure: 1.06 MPa (10.6 bar).
• Dimensions
  • Typical mean inside diameters include 14, 15, 15.9 (5/8), 19 (3/4) and 25.4 mm (1); other sizes permitted as needed.
• Testing and performance
  • Gas leakage (Method A for type/production and Method B for routine tests)
  • Refrigerant permeation (R1234yf permeation limits and determination)
  • Ageing, low-temperature performance, vacuum resistance
  • Length change under pressure, minimum bursting pressure and proof pressure
  • Extraction by liquid R1234yf; ozone resistance; hose cleanliness
  • Impulse (pressure fatigue) testing; moisture ingression grades (ML, Mm)
  • Coupling integrity (sealability) - coupling used in service must be tested
  • Vibration transmissibility - quantifies low-vibration performance
  • Test frequency, marking, test reports, packaging and storage recommendations
• Normative annexes
  • Detailed test procedures (permeation, low-temperature, impulse, moisture ingression, coupling sealability, vibration transmissibility, etc.)

Applications and users

ISO 8066-4:2023 is intended for:

• Automotive OEMs and HVAC system designers specifying R1234yf suction hoses
• Hose and hose-assembly manufacturers and suppliers ensuring compliance
• Quality and test laboratories performing type, production and routine tests
• Aftermarket and service providers replacing or certifying A/C hoses
• Regulatory bodies and procurement teams referencing safety, durability and refrigerant compatibility

Practical use: specifying and verifying hoses that minimize cabin vibration while ensuring compatibility, leak-tightness and durability with R1234yf refrigerant in passenger vehicles.

Related standards

• ISO 1402 - Hydrostatic testing
• ISO 4671 - Measurement of hose dimensions
• ISO 8330 - Vocabulary for hoses and assemblies
• ISO 7326 - Ozone resistance testing
• ISO 23529 - Conditioning of rubber test pieces
• ISO/TR 11340 and other parts of the ISO 8066 series for related hose types

Keywords: ISO 8066-4:2023, R1234yf hoses, automotive air conditioning hoses, low vibration transmission, hose assemblies, refrigerant permeation, coupling integrity, hose testing standards.