Cylinder Requirements

RSPA Responds to NWSA Comments.

By Richard P. Schweitzer, Esq.

The Research and Special Programs Administration (RSPA) of the U.S. Department of Transportation has withdrawn new proposed requirements for the maintenance, requalification, repair and use of DOT-specification cylinders in light of opposing comments from NWSA and other industry groups (67 Federal Register 6667, February 13, 2002).

The proposal, Docket HM-220, would have amended the Hazardous Materials Regulations in three key areas to:

1. Establish four new DOT cylinder specifications, with metric markings, that would replace the current 12 cylinder specifications;
2. Prohibit the manufacture of cylinders made to DOT specifications 3A, 3AA, 3AX, 3AAX, 3AL, 3B, 3T, 3BN, 4B, 4BA, 4BW, 4B240ET and 4E after a five-year phase out period; and
3. Require ultrasonic testing and prohibit hydrostatic testing for requalification of metric-marked cylinders.

In addition, the requirement for metric-marked cylinders would have mandated that cylinders be marked with test pressure instead of service pressure.

NWSA Oppositions
NWSA's comments opposed marking cylinders with test pressure only, as service pressure markings are commonly used as a baseline to determine existing cylinder contents. NWSA also cited the expense of converting from psig to bar, including the cost of purchasing thousands of high pressure and low pressure fill gauges at $500 per gauge.

NWSA noted that safety policy favored retaining service pressure on cylinders, as cylinders are typically refilled several times a year, but are retested only once every five or ten years.

NWSA also opposed mandating ultrasonic testing as more costly and less widely available than hydrostatic testing, and posed additional safety concerns. The comments noted that ultrasonic testing procedures do not include a visual inspection of the valve threads, and that ultrasonic testing also fails to measure the ductility or strength of a cylinder. NWSA additionally described the initial investment and ongoing costs of ultrasonic testing equipment, and illustrated that RSPA's estimated costs were grossly understated.

Finally, NWSA's comments addressed the need to retain a DOT 3AA cylinder standard; the need for Canadian reciprocity; standards for visual cylinder inspections, valve threads and valve ratings; transportation of cylinders after the retest date; filling limits for liquid cylinders; pressure relief device standards; and cylinder valve protection.

RSPA Responds
RSPA received over 200 written comments on the proposal, and also held a series of public meetings to provide technical information on the proposals and to clarify certain industry comments.

As a result of reviewing the comments received, RSPA withdrew its proposal to establish four new metric-marked cylinder specifications and to prohibit manufacture of cylinders under the 12 current DOT specifications. It also withdrew the proposal to require ultrasonic testing of all metric-marked cylinders, although RSPA will continue to allow the use of ultrasonic testing to requalify cylinders under DOT exemptions.

This is an important victory for NWSA members and shows that the industry can work with government agencies to avoid costly and unnecessary additional regulations. It is not the end of the docket entirely, however. Part of the Notice of Proposed Rulemaking addressed standards for maintenance, requalification, repair and use of current DOT specification cylinders.

RSPA noted that even though it has withdrawn the proposals with regard to metric-marked cylinders, it intends to issue a final rule to address proposals applicable to current DOT specification cylinders under a new Docket, HM-220D. That final rule is expected to be published in mid-2002.