Preface
This is the first edition of CSA EXP2.1, Best practice for defueling, decommissioning, and disposal of compressed natural gas vehicle fuel containers. This Express Document is not a consensus publication; that is, it is not a Standard and it has not been formally reviewed or approved by a CSA Technical Committee.
The best practices outlined in this Express Document are intended to be used by industry, container owners and authorities having jurisdiction (AHJ) to safely and effectively remove containers from service. The following guidelines directed the development of the content of this Express Document:
a) Defueling, decommissioning, and disposing of CNG containers should only be done by a qualified person or agency, in a safe and compliant manner following best practices, manufacturer recommendations and proven methods.
b) CNG containers that have been damaged or have reached their end of life should be permanently removed from service using proven methods, in a safe and compliant manner following best practices, manufacturer recommendations and proven methods.
c) CNG containers should be destroyed or irrevocably rendered inoperable prior to being disposed, using proven methods applicable to the container’s type of construction, in a safe and compliant manner following best practices, manufacturer recommendations and proven methods.
The first edition of this Express Document will focus on natural gas containers since this is the immediate need of industry; the next edition (development to begin upon completion of the first edition) will include LNG tanks. A future edition will also include hydrogen containers.
CSA Group acknowledges that the development of this Document was made possible, in part, by the financial support of Natural Resources Canada, FortisBC Energy Inc., and Hexagon Composites.
Scope
1.1 General
This Express Document (herein referred to as this Document) contains requirements for the safe removal and disposal of compressed natural gas (CNG) containers from natural gas vehicle (NGV) service when the container(s):
a) has reached its end of life as indicated by the date on the container label;
b) has been condemned in accordance with visual inspection guidelines;
c) is no longer of value to an owner; or
d) has been deemed a public nuisance or imminent hazard by the local authority (abandoned, confiscated, or seized containers).
It is the owner’s responsibility to ensure that the CNG containers on the vehicle are defueled and removed by a qualified agency at the end of the container life (EOL). Once the container has been removed, the custodian of the container is responsible to dispose of the container safely.
Note: Owners should obtain paperwork to document transfer of custody.
1.2 Procedure overview
In general, the best practice for disposal of all condemned containers requires adherence to the following procedures:
a) safely defuel and purge the contents;
b) remove the valve and other fittings;
c) obliterate all markings and labels;
d) destroy the container; and
e) properly discard the container.
1.3 Container type
NGV 2 high-pressure containers are designated as follows:
Type 1. Metal.
Type 2. Resin impregnated continuous filament with metal liner with a minimum burst pressure of 125 percent of service pressure. This container is hoop-wrapped.
Type 3. Resin impregnated continuous filament with metal liner. This container is full-wrapped.
Type 4. Resin impregnated continuous filament with a non-metallic liner.
1.4 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.
