Draft Details

1.1 General
This Document contains recommendations for safely defueling, removing, or disposing of LNG tanks for storing fuel used for vehicle propulsion when the tank
a) requires defueling for any reason, including but not limited to inspection, repair, or maintenance
b) has reached its end of life as indicated by the “do not use after” date, if provided;
c) has been condemned in accordance with visual inspection guidelines;
d) is no longer of value to an owner; or
e) has been deemed a public nuisance or imminent hazard by the local authority (abandoned, confiscated, or seized tanks.
It is the owner’s responsibility to confirm that the LNG tank on the vehicle is defueled or removed by a qualified personnel whenever deemed required. Once the tank has been removed, the custodian of the tank is responsible to dispose the tank safely.
Note: Owners should obtain paperwork to document transfer of custody.

1.2 Exclusions
Recommendations for reusing or repurposing LNG fuel tanks are excluded from the scope of this specification. 

Additional associated exclusions include repurposed fuel tank mounting arrangements, valve configurations, pressure relief device (PRD) venting systems, and fuel system plumbing. 

For specific LNG fuel tank reuse requirements refer to NFPA 52 and guidance from the fuel tank manufacturer, the fuel system provider, and the authority having jurisdiction (AHJ).

1.3 Terminology
In this Document, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Document; “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 Document.
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.

1.4 Units of measurement
The values given in SI units are the units of record for the purposes of this Document. The values given in parentheses are for information and comparison only