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Interpretation Response #07-0002 ([UPS Hydrostatic Shop] [Mr. Robert A. Stewart])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: UPS Hydrostatic Shop

Individual Name: Mr. Robert A. Stewart

Location State: DC Country: US

View the Interpretation Document

Response text:

Feb 15, 2007

Mr. Robert A. Stewart
UPS Component Shop Supervisor                     
Reference No. 07-0002
UPS Hydrostatic Shop
UPS Aircraft Maintenance Hangar
750 Grade Lane
Louisville, KY 40213

Dear Mr. Stewart:

This is in reference to your January 4, 2007 letter to Mr. Frazer C. Hilder, Pipeline and Hazardous Materials Safety Administration's Office of the Chief Counsel, regarding the cylinder requalification requirements contained in § 180.205(g) of the Hazardous Materials Regulations (49 CFR Parts 171-180; HMR). Specifically, you ask whether the I % resolution and ±1% accuracy tolerances of the expansion indicating device (EID), as specified in§ 180.205(g)(2) and (g)(3)(ii), apply to the permanent expansion reading specified in § 180.205(g)(4)?

Tue answer is no. The EID is used to verify the accuracy of the test equipment system. The permanent expansion reading is used to evaluate the acceptance or rejection of a given tested cylinder.

Paragraph (g)(2) prescribes a resolution standard for an EID. In accordance with paragraph (g)(2), an EID must permit incremental reading of the cylinder expansion to 1% of the total expansion of each cylinder tested. Paragraph (g)(3)(ii) prescribes an accuracy standard for an EID. In accordance with paragraph (g)(3)(ii), an EID must provide a stable reading of a cylinder's expansion and must be accurate to ±1.0% of the total expansion of any cylinder tested that day.

Each day before retesting, the requalifier must use a calibrated cylinder, or other method authorized in writing by the Associate Administrator for Hazardous Materials Safety, to verify the accuracy of the test system. The test equipment must he verified to be accurate to within ± 1.0% of the calibrated cylinder's certificate values (see § 180.209(g)(4)). This can be accomplished using the EID by bringing the total expansion to the selected value shown on the calibrated cylinder certificate. Alternatively, this can be accomplished using the pressure indicating device by bringing the pressure to the selected value shown on the calibrated cylinder certificate. Regardless of the procedure used, the calibrated cylinder must show no permanent expansion. When the pressure is released, the EID must show zero (0) cc. If the pressure fails to return to zero (0) cc, the test system has not been proven to be accurate. The retester is not authorized to test cylinders to determine their suitability for service until the test system is proven to be accurate.

I hope this information is helpful. Please contact us if you have additional questions.

Sincerely ours,

Hattie L. Mitchell
Chief, Regulatory Review and Reinvention
Office of Hazardous Materials Standards


Regulation Sections

Section Subject
180.205 General requirements for requalification of specification cylinders