The Pipeline and Hazardous Materials Safety Administration (PHMSA) is proposing hazmat regulations revisions that address issues submitted by petitions from certain members of the industry that address structural integrity requirements for the design and construction of DOT406, DOT407, and DOT412 cargo tank vehicles; requirements for manhole assemblies; and pressure relief valves.
Among those submitting petitions were the Tank Trailer Manufacturers Association (TTMA), Keehn Service Corp, and Compressed Gas Association, according to the proposal published April 12 in the Federal Register. Comments on the proposal must be submitted by June 11, 2007.
PHMSA said Section 178.345-3 prescribes structural integrity requirements for the design and construction of DOT 406, DOT 407, and DOT 412 cargo tank motor vehicles. Paragraph (a) specifies the general requirements and acceptance criteria for structural integrity. TTMA requested the revision of paragraph (a) to reference TTMA Recommended Practice (RP) #96-97, Structural Integrity of DOT 406, DOT 407, and DOT 412 Cylindrical Cargo Tanks, Dec 1, 1997 Edition. This standard contains methods for calculating the structural integrity of DOT 406, DOT 407, and DOT 412 cylindrical cargo tanks in conformance with Sec. 178.345-3 and 178.345-8(e).
Section 178.345-5 prescribes requirements for manhole assemblies used on DOT 406, DOT 407, and DOT 412 cargo tank motor vehicles. Paragraph (f) specifies that all fittings and devices mounted on a manhole cover, coming in contact with the lading, must withstand the same static internal fluid pressure and contain the same permanent compliance markings as those prescribed in paragraph (e) for the manhole cover. Because paragraph (e) already requires the manhole cover to be marked with a statement certifying that the manhole cover meets the requirements in Sec. 178.345-5, TTMA (P-1372), PHMSA agreed that to mark the manhole's fittings is duplicative of the manhole cover marking requirement in paragraph (e). Therefore, it proposes to remove the redundant wording in paragraph (f).
Keehn Service Corp said Section 180.407 prescribes requirements for the periodic testing and inspection of specification cargo tanks. Paragraph (d)(3) of Sec. 180.407 requires each reclosing pressure relief valve that is required to be removed and tested to be able to open at the required set pressure and reseat to a leak-tight condition at 90 percent of the set-to-discharge pressure or the pressure for the applicable cargo tank specification. Paragraph (g)(1)(ii)(A) of Sec. 180.407 requires each self-closing pressure relief valve that is an emergency relief vent to open at the required set pressure and seat to a leak-tight condition at 90 percent of the set-to-discharge pressure or the pressure for the applicable cargo tank specification.