Interpretation Response #26-0052
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Koorsen Fire & Security
Individual Name: Brick Keltner
Location State: IN Country: US
View the Interpretation Document
Response text:
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
Regulation Sections
| Section | Subject |
|---|---|
| 180.203 | Definitions |
| 180.215 | Reporting and record retention requirements |