Interpretation Response #13-0131 ([Mr. Tim McLoughlin] [M & M Metrology, Inc.])
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Mr. Tim McLoughlin
Individual Name: M & M Metrology, Inc.
Location State: FL Country: US
View the Interpretation Document
Response text:
September 24, 2013
Mr. Tim McLoughlin
M & M Metrology, Inc.
272 South Military Trail
Deerfield Beach, FL 33442
Ref. No.: 13-0131
Dear Mr. McLoughlin:
This is in response to your June 19, 2013 email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to the calibration and certification of gauges used for pressure testing cylinders. You request clarification of the accuracy of the pressure indicating device as required under HMR § 180.205. Specifically, you ask if you are correct in calibrating an 1100 psig pressure gauge to ±5.5 psig (±0.5%) of its full range.
You are correct. In accordance with § 180.205(g)(3)(i) the pressure indicating device itself (the pressure gauge) must be certified as having and accuracy of ±0.5%, or better, of its full range.
Section 180.205(g)(3)(i) also provides that the pressure indicating device as part of the retest apparatus must be accurate to within ±1.0% of the prescribed test pressure of any cylinder being tested. Since the described gauge is calibrated to ±5.5 psig, the gauge would not be authorized for testing cylinders having a prescribed test pressure below 550 psig.
These requirements are consistent with the Compressed Gas Association Standard
CGA C¬-¬1¬¬-2009 paragraph 5.3.2.2 which provides that the pressure indicating device shall be manufactured and certified to an accuracy grade of ±0.5% or better, and the pressure indicating device shall permit reading of pressures to within 1% of the test pressure of each cylinder tested.
I trust this information is helpful. If you have further questions, please do not hesitate to contact this office.
Sincerely,
Delmer Billings
Senior Regulatory Advisor
Standards and Rulemaking Division
180.205