Interpretation Response #23-0042
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Galiso, Inc.
Individual Name: Mr. Jon Davignon
Location State: CO Country: US
View the Interpretation Document
Response text:
April 11, 2024
Mr. Jon Davignon
VP Sales and Service Manager
Galiso, Inc.
22 Ponderosa Ct
Montrose, CO 81401
Reference No. 23-0042
Dear Mr. Davignon:
This letter is in response to your April 21, 2023, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to cylinder calibration testing systems. In your email, you cite paragraph (g) of Section 7.3.2 of Compressed Gas Association (CGA) publication C-1-2016, "Methods for Pressure Testing Compressed Gas Cylinders, Eleventh Edition" for the proof pressure method, which indicates that the 30 second hold is only required at the highest verification pressure. You ask whether it is permitted to advance to the subsequent verification pressure during cylinder calibration once the current verification pressure is reached, rather than waiting the full minimum of 30 seconds as indicated in paragraph (h) of Section 5.5.2 of CGA C-1-2016 for the water jacket method.
The answer is no. The water jacket and proof pressure methods have separate calibration testing criteria specified in CGA C-1-2016. For the water jacket method, Section 5.2.1 of CGA C-1-2016 states that "the cylinder shall maintain test pressure for at least 30 seconds and as much longer as may be necessary to ensure its complete expansion." Section 5.5.2 of CGA C-1-2016 states that "it is not required to release the pressure after each verification pressure is reached. Once the pressure and expansion readings stabilize and the total expansion reading is recorded, the pressure may be increased to the next verification point." Section 5.5.2(h) also states that the tester must "stop the pressurization and hold for a minimum of 30 seconds when the selected verification pressure is reached." This means that pressure need not be released after stabilization, and that the 30 second hold applies at each verification pressure, not only the highest verification pressure.
I hope this information is helpful. Please contact us if we can be of further assistance.
Sincerely,
Steven Andrews
Acting Chief, Regulatory Review and Reinvention Branch
Standards and Rulemaking Division