Are there an exceptions or modifications to the adoption of NFPA 58?
Yes. The OSFM has made a requirement within the Part 200 rules that does not appear in the 2008 edition of NFPA 58. (This requirement is actually taken from a Technical Interim Amendment – TIA – that was made to NFPA 58, but the language may not appear in some copies of NFPA 58). The modification affects containers of specific sizes that may be used to contain both ammonia (NH3) and LP-Gas by placing a prohibition on such interchanging of products. Specifically the rule provides that: Except for containers used in cargo tank vehicle service, ASME containers of 3,000 gallons water capacity or less used to store anhydrous ammonia shall not be converted to LP-gas fuel service. For other size containers where a container of approved construction and design has been used to contain anhydrous ammonia or any other product, the container shall be thoroughly purged of the other product before it is placed into service for liquefied petroleum gas and a tag attesting to the thorough purging of th
