Interpretation Response #24-0118
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: The Hartford Steam Boiler Inspection and Insurance Co.
Individual Name: Timothy J. Nuoffer
Location State: CT Country: US
View the Interpretation Document
Response text:
April 21, 2025
Timothy J. Nuoffer
Field Services Manager
The Hartford Steam Boiler Inspection and Insurance Co.
One State Street
P.O. Box 5024
Hartford, CT 06102-5024
Reference No. 24-0118
Dear Mr. Nuoffer:
This letter is in response to your November 27, 2024, letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to rethreading of DOT 3-series specification cylinders. Specifically, you ask about re-tapping (also known as rethreading) in accordance with §§ 180.205(f)(7) and 180.212, respectively.
We have paraphrased and answered your questions as follows:
Q1. Does Letter of Interpretation (LOI) Reference No. 09-0111 allow repair facilities with an approval in accordance with § 107.805 to rethread DOT 3-series specification cylinders?
A1. PHMSA's Office of Hazardous Materials Safety provides written clarifications of the HMR in the form of LOIs, in accordance with 49 CFR 105.20(a). These letters reflect the agency's current application of the regulations to the specific facts presented by the person requesting the clarification. LOIs are not generally applicable, do not create legally-enforceable rights or obligations, and are provided to help the specific requestor understand how to comply with the regulations in their specific circumstances. Section 180.212(a) requires a repair facility to hold an approval issued under the provisions of § 107.805 to repair a DOT 3-series or a seamless United Nations (UN) pressure receptacle, which includes rethreading a DOT 3-series specification cylinder.
Q2. Is the cylinder manufacturer permitted to perform rethreading of DOT 3-series specification cylinders under the exception in § 180.212(b)(2) required to be the original cylinder manufacturer?
A2. No. The rethreading of a DOT 3-series specification cylinder is not required to be performed by the original manufacturer. However, please note the cylinder manufacturer performing rethreading must be a manufacturer of the specific cylinder type for which the rethreading is being performed. PHMSA recognizes that § 180.205(f)(7) states re-tapping of cylinder threads is not permitted, except by the original manufacturer, as provided in § 180.212. In an earlier rulemaking , PHMSA revised the wording in § 180.212(b)(2) to clarify that the rethreading of cylinders may be performed by a manufacturer of the type of cylinder being rethreaded instead of limiting the work to the original manufacturer, who may no longer be in business. PHMSA may consider a similar revision to § 180.205(f)(7) in a future rulemaking.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Dirk Der Kinderen
Chief, Standards Development Branch
Standards and Rulemaking Division
107.805, 180.205(f)(7), 180.212, 180.212(a), 180.212(b)(2)