# MansourGavin, LPA — Hazardous Materials Safety Interpretation **Citation:** 16-0111 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2017-04-05 16-0111 response to MansourGavin, LPA concerning 178.35, 178.36, 178.42. ## Document text <<>> U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration 1200 New Jersey Avenue, SE Washington, DC 20590 APR 0 5 2017 Mr. Jeffrey M. Embleton, Esq. MansourGavin, LP A 1001 Lakeside A venue, Suite 1400 Cleveland, OH 44114 Reference No. 16-0111 Dear Mr. Embleton: This letter is in response to your June 21, 2016, letter on behalf of your client requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the inspection of threads on DOT 3A, 3AX, and 3E seamless steel cylinders. You state that in order to ensure the threads are built "to gauge," your client uses a statistical sampling size of C = 0, AQL = 1.5% (per Acceptance Number Sampling Plans, N.L. Squeglia, ASQC, 4th Edition), along with additional processes identified in an established quality plan. You also provide examples of more stringent statistical sampling sizes, such as C = 0, AQL = 0.4% and C = 0, AQL = 0.1 %, and specifically ask which is the most appropriate method for the inspection of cylinder threads. In accordance with§§ 178.36(h)(l) and 178.42(e)(l), the threads on a DOT 3A, 3AX, or 3E cylinder are required to be "clean cut, even, without checks, and to gauge." It is the manufacturer's responsibility determine how best to ensure the threads on each cylinder meet the appropriate specification, whether by testing each or by some sample set according to a quality plan. Please note that a DOT 3A, 3AX, or 3E cylinder is also required to be inspected and analyzed by an inspector as designated in§ 178.35(bl. Specifically, the designated inspector is required in accordance with§ 178.35(c)(3)(vi) to "verify threads by gauge" to determine cylinder compliance with the applicable specification. Furthermore,§ 178.35(c)(4) requires that the inspector's report be prepared in accordance with Compressed Gas Association (CGA) C-11. Specifically, CGA C-11 requires that for seamless cylinders, "threaded openings in each cylinder shall be inspected and gauged for compliance with the design specification as well as quality. •As specified in§ l 78.35(b), a DOT 3A or 3AX cylinder must be inspected and verified by an Independent Inspection Agency (IIA). A DOT 3E cylinder must be inspected and verified by either an IIA or a competent insnector of the manufacturer. <<>> Performance of this inspection shall be verified by the inspector." Therefore, in addition to the manufacturer's responsibility, the designated inspector must inspect the cylinders in order to verify and assure that the threads are built "to gauge." I hope this information is helpful. Please contact us if we can be of further assistance. $2/ci u~e0 Chief, Standards Development Branch Standards and Rulemaking Division <<>> Dodd, Alice (PHMSA) From: Sent: To: Subject: Attachments: Rivera, Jordan CTR (PHMSA) Friday, June 24, 2016 1:46 PM Hazmat Interps FW: Gauging of threads on Specification Cylinders Request re Gauging of Threads on spec cylinder 6-21-16.pdf Hi Shante/Alice, Please submit this as a letter of interpretation . Please let me know if you have any questions. Thanks, Jordan From: Ellen Stefanac [mailto :EStefanac@mqqmlpa.com] On Behalf Of Jeffrey Embleton Sent: Tuesday, June 21, 2016 10:16 AM To: PHMSA HM lnfoCenter Subject: Gauging of threads on Specification Cylinders Jeffrey :M. P.m6Ceton •• I MANSOURGAVIN I LP.A North Point Tower 1001 Lakeside Ave., Suite 1400 Cleveland, Ohio 44114 8 216.453.5905 (Direct Dial) 8 216-310-3416 (Cell) • 216.523.1500 ~ 216.523.1705 121 JEmbleton@mggmlpa.com www.mggmlpa.com CONFIDENTIALITY NOTE: THE INFORMATION IN THIS E-MAIL MESSAGE AND ANY ATTACHMENTS IS SENT BY AN ATTORNEY OR HIS/HER AGENT, IS INTENDED TO BE CONFIDENTIAL AND FOR THE USE OF ONLY THE INTENDED RECIPIENT. THE INFORMATION MAY BE PROTECTED BY ATTORNEY/CLIENT PRIVILEGE, WORK PRODUCT IMMUNITY OR OTHER LEGAL RULES. IF THE READER OF THIS MESSAGE IS NOT THE INTENDED RECIPIENT, YOU ARE NOTIFIED THAT RETENTION , DISSEMINATION, DISTRIBUTION OR COPYING OF THIS E-MAIL IS STRICTLY PROHIBITED. IF YOU RECEIVE THIS E-MAIL IN ERROR, PLEASE NOTIFY US IMMEDIATELY BY RETURN E-MAIL OR BY TELEPHONE AT U.S.A. (216) 523-1500 AND DELETE THIS MESSAGE. THANK YOU. 1 <<>> • • I tv1ANSOUR GAVIN I LPA Jeffrey M. Embleton, Esq. JEmbleton@mgqmlpa.com Direct Dial 21 6-453-5905 June 21, 2016 U.S. DOT PHMSA Office of Hazardous Materials Standards Attn: PHH-10 East Building 1200 New Jersey Avenue, SE. Washington, DC 20590-0001 In re: Request for Interpretation Regarding Gauging of Threads on Specification Cylinders Dear Representative, Our Client ("Company A") is a registered manufacturer of DOT Specification Cylinders. As a result, Company A is subject to the inspection requirements set forth in 49 CFR 178.36(h)(1) and 178.42(e)(1) (together, the "Regulations"), which address the specifications for 3A and 3AX seamless steel cylinders and 3E seamless steel cylinders, respectively. On behalf of Company A, we are seeking an interpretation of the Regulations. With respect to the inspections referenced in the Regulations, Company A has historically used statistical sampling sizes of C=O, AQL = 1.5% (per Acceptance Number Sampling Plans, N.L. Squeglia, ASQC, 4th Edition), coupled with in-process inspection according to a pre-determined quality plan for the relevant products. These sampling plans are widely accepted quality control techniques used in a variety of industries, and have been successfully utilized by Company A for more than twenty years. However, a recent review of the Regulations has resulted in our client seeking this request for interpretation, specifically as to the requirement that "Threads must be clean cut, even, without checks, and to gauge." See 49 CFR 178.36(h)(1 ), 49 CFR 178.42(e)(1 ). Accordingly, we submit the following questions for your consideration: 01: Can proven statistical sampling, as described above in the second paragraph, be used for thread inspection and meet the requirement" ... to gauge" as cited in to 49 CFR 178.36(h)(1) and 49 CFR 178.42(e)(1)? 1111 Nor th Point Tower I 1001 Lokeside Avenue I Suite 1 400 I Cleveland , OH 44114 I p : 21 6.523 .1500 I f : 216 .523.1705 I w: mggmlpa.com <<>> MANSOUR GAVIN LPA U.S. DOT PHMSA Office of Hazardous Materials Standards June21,201 6 Page 2 02: If the sampling plan noted in 01 is interpreted as not meeting the requirement " ... to gauge" as cited in to 49 CFR 178.36 (h)(1) and 49 CFR 178.42(e)(1 ), would a more stringent statistical sampling plan be deemed acceptable towards meeting this aforementioned requirement, such as C=O, AOL = 0.4%; or C=O, AOL = 0.1 %? If so, please advise which of these sampling plans would be deemed acceptable. Your help in interpreting the Regulations with respect to thread gauging sampling plans is greatly appreciated. Feel free to contact the undersigned for any questions or reply if you have any questions. Best regards, JME:ens ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `fb8455f12baac852877feb515cb2fd6175ee172f9018cace1c25bdd2098f4d22` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-23T01:03:50.332Z - Document slug: `phmsa-interpretation-16-0111` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "MansourGavin, LPA" ], "individuals": [ "Mr. Jeffrey Embleton, Esq" ], "refIds": [ "16-0111" ], "catalogDates": [ "2017-04-05" ], "catalogParts": [ 178 ], "catalogRowCount": 3, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/54971" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "178.35", "178.36", "178.36(h)(l)", "178.42", "178.42(e)(l)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/17835", "https://www.phmsa.dot.gov/regulations/title49/section/17836", "https://www.phmsa.dot.gov/regulations/title49/section/17842" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/160111.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/160111.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/legacy/interpretations/Interpretation%20Files/2017/160111.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/16-0111-a0cb376837.pdf", "pdfArtifactSha256": "49e50cfd53e9ebb2f674ef117eb15e9730aa783ebb7acde42a7609804bb80180", "extractedTextPath": "data/sources/phmsa-interpretations/16-0111-a0cb376837.v2.txt", "extractedTextSha256": "f483194db85371f431bc785d91093f5b2af94fb46b2c493960b457e298af3b2e", "pageCount": 5, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```