ISO 20766-8:2023

Overview

ISO 20766-8:2023 is an international standard specifying the general requirements and design principles for fuel pump components used in liquefied petroleum gas (LPG) fuel systems in road vehicles. This standard applies to LPG fuel pumps intended for motor vehicles as defined by ISO 3833 and supports mono-fuel, bi-fuel, and dual-fuel applications utilizing gaseous fuels in accordance with ISO 9162. The document excludes fuel containers, stationary gas engines, mounting hardware, electronic fuel management, and refuelling receptacles from its scope.

Key focus areas of ISO 20766-8 include construction, assembly, marking, and performance testing of LPG fuel pumps intended to operate within specific pressure ranges relevant to butane- and propane-rich LPG blends. The standard ensures safety, reliability, and compatibility of LPG fuel pumps in automotive applications.

Key Topics

• Scope and Applicability
  Details the types of vehicles and LPG fuel systems to which the standard applies, explicitly excluding certain components such as fuel containers and refuelling receptacles.

• Marking Requirements
  Each LPG fuel pump must have clear and indelible markings including:

  • Manufacturer’s name or trademark
  • Model designation or part number
  • Working pressure and temperature range
  • Fabrication date (year and month)
    Recommended additional markings include direction of flow, fuel type, electrical ratings, certification symbols, and relevant ISO reference.

• Design and Construction

  • Fuel pumps must withstand maximum operating pressures, typically within 110 kPa to 840 kPa gauge pressure, adjustable by ratio for other pressures.
  • Electrical insulation is mandated to prevent sparking, ensuring isolation of electrical systems from LPG-containing parts with insulation resistance >10 MΩ.
  • Protection against environmental factors with electrical connections complying with IP40 protection degree (IEC 60529).
  • Safety design to prevent outlet pressure exceeding 3,000 kPa or component working pressure under fault conditions such as tubing blockage by automatic pump shutdown or LPG recirculation.

• Testing Requirements
  Fuel pumps are subjected to rigorous tests to verify safety and durability including:

  • Hydrostatic strength testing at 2.25 times the working pressure.
  • Leakage tests under high and low temperature conditions with a maximum allowable leak rate of 15 cm³/h after conditioning at temperature extremes.
  • Additional tests like external leakage, corrosion resistance, LPG compatibility for non-metallic materials, and temperature cycling may apply.

Applications

ISO 20766-8:2023 is primarily designed for manufacturers and engineers involved in the development and certification of LPG fuel pump components for road vehicles. Its practical value includes:

• Vehicle manufacturers ensuring the integration of safe and compliant LPG fuel pumps within mono-fuel, bi-fuel, or dual-fuel vehicle configurations.
• Component suppliers designing fuel pumps to meet strict performance, safety, and marking criteria to facilitate global market acceptance.
• Regulatory bodies and certification agencies leveraging this standard to assess conformity of LPG fuel system components to international safety and quality benchmarks.
• Maintenance and repair sectors benefiting from standardized marking for correct replacement and ensuring compliance with safety norms during servicing.

The standard supports the safe expansion of LPG-fueled vehicles, promoting environmentally friendly alternatives while maintaining reliability and regulatory compliance.

Related Standards

• ISO 20766 Series
  The LPG fuel system component series, where:

  • Part 1 covers general requirements and definitions for LPG components.
  • Part 2 addresses performance and general test methods for LPG fuel systems.
    Other parts detail various LPG system components and testing protocols ensuring comprehensive system safety.

• ISO 3833
  Defines vehicle types and terminology relevant to the scope of LPG components in motor vehicles.

• ISO 9162
  Specifies the classification and specifications for LPG gaseous fuels used in motor vehicles.

• IEC 60529
  Specifies the degree of protection provided by electrical enclosures (IP Code), relevant for ensuring appropriate electrical safety and environmental protection of LPG fuel pump components.

Adhering to ISO 20766-8:2023 is crucial for automotive LPG fuel pump design, ensuring safe, reliable, and test-verified components that comply with global safety standards. Implementing this standard enables stakeholders to advance the adoption of LPG as a clean, efficient automotive fuel alternative.