PHMSA Response Letter

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October 13, 2009

Mr. Steven T. Gentry
Regulatory Affairs Manager
Worthington Cylinder Corporation
1085 Dearborn Drive
Columbus, Ohio 43085

Ref. No.: 09-0177

Dear Mr. Gentry:

This responds to your letter regarding a previous interpretation on the proof pressure test requirements in the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180), as they apply to DOT-4 series cylinders used for refrigerant gas recovery. Specifically, you ask us to rescind a previously issued letter of clarification on this subject (Ref. No. 03-0164) because it is inconsistent with Transport Canada and industry guidelines.

Section 180.209(e) establishes proof pressure test requirements for DOT 4B, 4BA, 4BW, and 4E cylinders used exclusively for certain hazardous materials, including refrigerant gases. The requirements specified in this section apply only to cylinders used to transport the listed materials when they are commercially free of corroding components. Such cylinders may be requalified by volumetric expansion testing every 12 years, or by proof pressure testing every 7 years after expiration of the first 12-year period. You are correct that § 180.209(e) does not apply to DOT-4 series cylinders used to transport reclaimed refrigerant gases because these gases are considered corrosive due to contamination. The applicable retest period for DOT 4-series cylinders used to transport reclaimed refrigerant gases is every 5 years using the volumetric expansion method.

To clarify the confusion and correct this misunderstanding, we are rescinding our previous letter of clarification.

Sincerely,

Charles E. Betts
Chief, Standards Development
Office of Hazardous Materials Standards

180.209(e)