# Koorsen Fire & Security — Hazardous Materials Safety Interpretation **Citation:** 26-0052 **Type / status:** guidance / guidance **Agency:** Pipeline and Hazardous Materials Safety Administration **Effective:** Not stated **Published:** 2026-07-27 26-0052 response to Koorsen Fire & Security concerning 180.203, 180.215. ## Document text <<>> Baker, Y. 26-0052 Mr. Shane Kelley Director, Standards and Rulemaking Division U.S. DOT/PHMSA (PHH-10) 1200 New Jersey Avenue, SE East Building, 2nd Floor Washington, DC 20590 Brick Keltner Corporate Shop Trainer Koorsen Fire & Security 2820 N. Webster Indianapolis, In 46219 Telephone 317-225-4785 Email: brick.keltner@koorsen.com Mr. Kelley, I would like a Formal Interpretation of 49 CFR 180.215(b)(1). Reporting & record retention for Calibration test records. The question that I have relates to the Calibrated Cylinder serial number. In the above standard it states that the serial number of the Calibrated Cylinder must be on the calibration / test records. Is that for Water Jacket testing as well as Proof Pressure testing? I have always taken the standards to mean for both methods unless it is otherwise stated. 49 CFR references CGA C-1 in multiple instances. CGA C-1 - 5.4 states – A calibrated cylinder is required when performing the verification procedure for test methods where volumetric expansion determinations are required. CGA C-1 - 7.3.2(b) states – Attach a suitable liquid-filled pressure vessel to the test system (i.e., a cylinder with a rated working pressure covering the highest proof test pressure to be encountered). This vessel provides a “volume” against which to pump. The question is – Does the cylinder used to calibrate a Proof Pressure system need to have a serial number that is recorded on the calibration / test records? Or is that only required for Water Jacket & Direct Expansion testing? Thank you for any information that you can give me. Brick Keltner, Koorsen Fire & Security <<>> 1200 New Jersey Avenue, SE Washington, DC 20590 U.S. Department of Transportation Pipeline and Hazardous Materials Safety Administration July 27, 2026 Brick Keltner Corporate Shop Trainer Koorsen Fire & Security 2820 N. Webster Indianapolis, IN 46219 Reference No. 26-0052 Dear Mr. Keltner: This letter is in response to your April 27, 2026 letter requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the recordkeeping requirements for cylinder requalification. Specifically, you ask whether the requirement in § 180.215(b)(1) to record the serial number of the cylinder used to calibrate a proof pressure system applies to proof pressure testing, or only to volumetric expansion testing. No. A “calibrated cylinder” (see CGA Pamphlet C-1 2016, Methods for Pressure Testing Compressed Gas Cylinders, Sections 3.2.7 and 5.4) is a specially designed cylinder with known expansion values. A “calibrated cylinder” is used to demonstrate integrity of test systems used to determine volumetric expansion (e.g., the water jacket method). As defined in § 180.203, a “proof pressure test” is performed by interior pressurization without the determination of a cylinder’s expansion, and thus, there is no need for a “calibrated cylinder.” Therefore, recording a calibrated cylinder’s serial number is not required for proof pressure test records. According to CGA C-1, Section 7.3.2, a liquid-based proof pressure test system is verified by attaching a standard cylinder with a rated working pressure that covers the highest proof test pressure expected during the day’s testing. The cylinder used in the system verification is not required to be a calibrated cylinder. However, to demonstrate compliance with the verification requirement in CGA C-1, Section 7.3.2, a facility must document the standard cylinder used during the daily system check. Maintaining a record of the standard cylinder’s serial number and rated working pressure is necessary to verify that the cylinder meets the minimum pressure requirements for that day’s testing. <<>> The system verification includes the use of a reference gauge or a master gauge. Calibration requirements for all components of the system (pressure indicating device, master gauge, reference gauge) must be periodically calibrated in accordance with Appendix B of CGA Pamphlet C-1. For all calibrated devices, the certificate of calibration shall be maintained on file at the facility. 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 ## Provenance - Official: Yes - Source: - Source ID: `phmsa` - SHA-256: `d038bcfe30704ef051ab80eecc2bf5b81fff9b2eaad119452f96d131ad2df115` - Retrieved: 2026-08-20T00:59:31.977Z - Exported: 2026-08-24T05:13:26.031Z - Document slug: `phmsa-interpretation-26-0052` ### Source metadata ```json { "materialSubtype": "interpretation", "interpretationArea": "hazardous_materials", "representation": "full_text_from_official_pdf", "companies": [ "Koorsen Fire & Security" ], "individuals": [ "Brick Keltner" ], "refIds": [ "26-0052" ], "catalogDates": [ "2026-07-27" ], "catalogParts": [ 180 ], "catalogRowCount": 2, "sourceRecordUrls": [ "https://www.phmsa.dot.gov/node/84301" ], "linkedAttachmentUrls": [], "unavailableResponseUrls": [], "duplicateRepresentationUrls": [], "citedSections": [ "180.203", "180.215", "180.215(b)(1)" ], "catalogPageUrls": [ "https://www.phmsa.dot.gov/regulations/title49/section/180203", "https://www.phmsa.dot.gov/regulations/title49/section/180215" ], "pdfUrls": [ "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-07/260052.pdf" ], "representations": [ { "viewUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-07/260052.pdf", "detailUrl": null, "detailHtmlPath": null, "pdfUrl": "https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-07/260052.pdf", "pdfArtifactPath": "data/sources/phmsa-interpretations/26-0052-ab26023b92.pdf", "pdfArtifactSha256": "e3c0ce8b3ae6cecaed2b3d0cd0c640c0444c2f95d556248888ef2d9d5804ce3d", "extractedTextPath": "data/sources/phmsa-interpretations/26-0052-ab26023b92.v2.txt", "extractedTextSha256": "711bd13c380f39539272cdf7dd1e7deecfb066a784ec9d110dace8b26deb39fb", "pageCount": 3, "extractionVersion": 2 } ], "caveat": "Interpretations apply regulations to the facts presented and do not create independently enforceable requirements.", "jurisdiction": "US" } ```