{"operation":"document","citation":"26-0052","title":"Koorsen Fire & Security — Hazardous Materials Safety Interpretation","source_type":"guidance","agency":"Pipeline and Hazardous Materials Safety Administration","status":"guidance","official":true,"published_on":"2026-07-27","effective_on":null,"summary":"26-0052 response to Koorsen Fire & Security concerning 180.203, 180.215.","machine_formats":{"json":"https://regulus.evalyn.ai/document/phmsa-interpretation-26-0052.json","markdown":"https://regulus.evalyn.ai/document/phmsa-interpretation-26-0052.md"},"app_url":"https://regulus.evalyn.ai/document/phmsa-interpretation-26-0052","source_url":"https://www.phmsa.dot.gov/sites/phmsa.dot.gov/files/2026-07/260052.pdf","body":"<<<PAGE 1>>>\n\nBaker, Y.\n26-0052\nMr. Shane Kelley\nDirector, Standards and Rulemaking Division\nU.S. DOT/PHMSA (PHH-10)\n1200 New Jersey Avenue, SE East Building, 2nd Floor\nWashington, DC 20590\nBrick Keltner\nCorporate Shop Trainer\nKoorsen Fire & Security\n2820 N. Webster\nIndianapolis, In 46219\nTelephone 317-225-4785\nEmail: brick.keltner@koorsen.com\nMr. Kelley, I would like a Formal Interpretation of 49 CFR 180.215(b)(1). Reporting & record\nretention for Calibration test records.\nThe question that I have relates to the Calibrated Cylinder serial number. In the\nabove standard it states that the serial number of the Calibrated Cylinder must be on the\ncalibration / test records. Is that for Water Jacket testing as well as Proof Pressure testing?\nI have always taken the standards to mean for both methods unless it is otherwise\nstated. 49 CFR references CGA C-1 in multiple instances.\nCGA C-1 - 5.4 states – A calibrated cylinder is required when performing the\nverification procedure for test methods where volumetric expansion determinations are\nrequired.\nCGA C-1 - 7.3.2(b) states – Attach a suitable liquid-filled pressure vessel to the test\nsystem (i.e., a cylinder with a rated working pressure covering the highest proof test\npressure to be encountered). This vessel provides a “volume” against which to pump.\nThe question is – Does the cylinder used to calibrate a Proof Pressure system need to have\na serial number that is recorded on the calibration / test records? Or is that only required\nfor Water Jacket & Direct Expansion testing?\nThank you for any information that you can give me. Brick Keltner, Koorsen Fire & Security\n\n<<<PAGE 2>>>\n\n1200 New Jersey Avenue, SE\nWashington, DC 20590\nU.S. Department\nof Transportation\nPipeline and Hazardous\nMaterials Safety\nAdministration\nJuly 27, 2026\nBrick Keltner\nCorporate Shop Trainer\nKoorsen Fire & Security\n2820 N. Webster\nIndianapolis, IN 46219\nReference No. 26-0052\nDear Mr. Keltner:\nThis letter is in response to your April 27, 2026 letter requesting clarification of the Hazardous\nMaterials Regulations (HMR; 49 CFR Parts 171-180) applicable to the recordkeeping\nrequirements for cylinder requalification. Specifically, you ask whether the requirement in\n§ 180.215(b)(1) to record the serial number of the cylinder used to calibrate a proof pressure\nsystem applies to proof pressure testing, or only to volumetric expansion testing.\nNo. A “calibrated cylinder” (see CGA Pamphlet C-1 2016, Methods for Pressure Testing\nCompressed Gas Cylinders, Sections 3.2.7 and 5.4) is a specially designed cylinder with known\nexpansion values. A “calibrated cylinder” is used to demonstrate integrity of test systems used to\ndetermine volumetric expansion (e.g., the water jacket method). As defined in § 180.203, a\n“proof pressure test” is performed by interior pressurization without the determination of a\ncylinder’s expansion, and thus, there is no need for a “calibrated cylinder.”\nTherefore, recording a calibrated cylinder’s serial number is not required for proof pressure test\nrecords. According to CGA C-1, Section 7.3.2, a liquid-based proof pressure test system is\nverified by attaching a standard cylinder with a rated working pressure that covers the highest\nproof test pressure expected during the day’s testing. The cylinder used in the system verification\nis not required to be a calibrated cylinder. However, to demonstrate compliance with the\nverification requirement in CGA C-1, Section 7.3.2, a facility must document the standard\ncylinder used during the daily system check. Maintaining a record of the standard cylinder’s\nserial number and rated working pressure is necessary to verify that the cylinder meets the\nminimum pressure requirements for that day’s testing.\n\n<<<PAGE 3>>>\n\nThe system verification includes the use of a reference gauge or a master gauge. Calibration\nrequirements for all components of the system (pressure indicating device, master gauge,\nreference gauge) must be periodically calibrated in accordance with Appendix B of CGA\nPamphlet C-1. For all calibrated devices, the certificate of calibration shall be maintained on file\nat the facility.\nI hope this information is helpful. Please contact us if we can be of further assistance.\nSincerely,\nDirk Der Kinderen\nChief, Standards Development Branch\nStandards and Rulemaking Division","truncated":false,"body_characters":4328}