ISO 22760-3:2024

Overview

ISO 22760-3:2024 specifies the definitions and general requirements for the 85% stop valve used in dimethyl ether (DME) fuel system components in road vehicles, as defined by ISO 3833. This standard outlines design principles, performance requirements, marking, and documentation for manufacturers and users of 85% stop valves in vehicles powered by gaseous fuels, in accordance with ISO 16861.

The 85% stop valve plays a vital safety role in limiting the filling level of DME fuel containers, helping to maintain effective headspace and prevent overfilling. This standard is relevant for component designers, vehicle manufacturers, and regulatory authorities involved in DME-powered road vehicle development.

Key Topics

• Scope and Applicability:

  • Focuses on 85% stop valves for road vehicles using DME as a gaseous fuel.
  • Excludes fuel containers (unless specifically referenced), stationary engines, marine, rail, or aircraft DME installations, electronic fuel management, and refueling receptacles.

• Design and Assembly Requirements:

  • Valves must switch to cut-off at 85% of container volume (with specific tolerance limits) when the vehicle is horizontally oriented.
  • Compatible with standard installation methods and any required level indicators.
  • Electrically operated valves must switch to cut-off when power is off and must pass insulation resistance and overvoltage tests.

• Performance and Testing:

  • Hydrostatic strength testing at 2.25 times working pressure.
  • Leakage assessment at specified temperatures and pressures.
  • Cycle durability testing across 6,000 operational cycles between open and cut-off positions.
  • Deformation and float integrity checks, including a float pressure test with no visible damage allowed.

• Marking and Identification:

  • Mandatory markings: manufacturer’s name, model designation, working pressure and temperature.
  • Recommended markings: flow direction, fuel type, electrical ratings (if required), certification details, and date/serial code.
  • Components must be traceable for safety and compliance.

Applications

• Vehicle Safety:
  The standard ensures that DME fuel systems are protected against overfilling, which can lead to hazardous conditions. Properly functioning 85% stop valves help maintain optimal operation and prolong the life of road vehicle DME fuel containers.

• Compliance and Quality Assurance:

  • Manufacturers can reference this standard to design and test 85% stop valves that are compliant with international safety norms.
  • Regulatory bodies can use ISO 22760-3:2024 as a baseline when certifying road vehicles equipped with DME fuel systems.

• Industry Adoption:

  • Facilitates interoperability and component compatibility across DME vehicle platforms.
  • Supports global harmonization of DME fuel system safety standards, enabling smoother market access and international trade.

Related Standards

• ISO 22760-1: General requirements and definitions for DME fuel system components.
• ISO 22760-2: Performance and general test methods for DME system components.
• ISO 16861: Specifications of dimethyl ether (DME) fuels.
• ISO 3833: Terms related to road vehicles.
• Other relevant standards may include material testing and compatibility guidelines such as ISO 188, ISO 11114-2, and various corrosion and ageing test standards.

By referencing ISO 22760-3:2024, organizations ensure consistent quality, reliability, and safety in the implementation of 85% stop valves within DME fuel systems for road vehicles, supporting the transition to cleaner alternative fuels and improving overall vehicle safety.