Road vehicles — Liquefied natural gas (LNG) fuel system components — Part 20: Flexible fuel or vent lines

1.1

This Standard specifies tests and requirements for the flexible fuel line or vent line for service temperatures colder than –40 °C (–40 °F) and cryogenic conditions, a liquefied natural gas fuel system component intended for use on the types of motor vehicles defined in ISO 3833.

This Standard is not applicable to the following:

a) fuel containers;

b) stationary gas engines;

c) container mounting hardware;

d) electronic fuel management; or

e) refuelling receptacles.

1.2

It is recognized that miscellaneous components not specifically covered herein can be examined to meet the criteria of this Standard when tested according to the appropriate functional tests.

1.3

All references to pressure in this Standard are to be considered gauge pressures unless otherwise specified.

1.4

This standard is based upon a maximum allowable working pressure (MAWP) for natural gas as a fuel of 1.6 MPa (232 psig). Other MAWPcan be derived by adjusting the pressure by the appropriate factor (ratio). For example, 2 MPa (290 psi) MAWP systems will require the pressures to be multiplied by 1.25.

1.5

In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.

1.6

The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.