USA Banner

Official US Government Icon

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure Site Icon

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

U.S. Department of Transportation U.S. Department of Transportation Icon United States Department of Transportation United States Department of Transportation

Interpretation Response #14-0112 ([Hydro-Test Products, Inc.] [Mr. Tom Sauta])

Below is the interpretation response detail and a list of regulations sections applicable to this response.

Interpretation Response Details

Response Publish Date:

Company Name: Hydro-Test Products, Inc.

Individual Name: Mr. Tom Sauta

Location State: MA Country: US

View the Interpretation Document

Response text:

September 18, 2014

Mr. Tom Sauta
Hydro-Test Products, Inc.
85 Hudson Road
Stow, MA 01775

Ref. No. 14-0112

Dear Mr. Sauta:

This responds to your April 15, 2014 letter requesting clarification of the cylinder pressure testing requirements under § 180.205(g) of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180). Specifically, you request clarification of the required accuracy for the pressure gauges used with retest equipment in relation to § 180.205(g)(3)(i).

According to your letter, a representative of an approved Independent Inspection Agency has questioned the accuracy of the pressure gauges used with your retest equipment and whether it conforms to § 180.205(g)(3)(i). The representative claims the gauges cannot be used in the ranges you specify for purposes of HMR requalification because they do not meet the requirements of section 5.3.22 of Compressed Gas Association (CGA) Pamplet C-1, Methods for Pressure Testing Compressed Gas Cylinders, 10th Ed., July 2009. You disagree with the claim because you believe this section confuses readability and accuracy requirements and also because CGA Pamphlet C-1 is not specifically referenced for use under the HMR. You request confirmation that the calibration data for your equipment that is provided in your letter conforms to § 180.205(g)(3)(i) for the pressure gauges used in the pressure test under § 180.205(g); and that CGA Pamphlet C-1 is not an enforceable reference document under the HMR.

Based on the information provided in your letter, it is the opinion of this Office that the accuracy of the pressure gauges used with your retest equipment conforms to § 180.205(g), specifically, § 180.205(g)(3)(i). This provision requires that each day before retesting, the retester must confirm that the pressure-indicating device (i.e., the pressure gauge), as part of the retest equipment, is accurate within ±1.0% of the prescribed test pressure of any cylinder tested that day. The pressure gauge, itself, must be certified as having an accuracy of ±0.5%, or better, of its full range, and must permit readings of pressure from 90%-110% of the minimum prescribed test pressure of the cylinder to be tested. The accuracy of the pressure indicating device within the test system can be demonstrated at any point within 500 psig of the actual test pressure for test pressures at or above 3,000 psig, or 10% of the actual test pressure for test pressures below 3,000 psig.

Furthermore, your understanding regarding CGA Pamphlet C-1 is correct. The document is not incorporated by reference and, therefore, is not a material made part of the regulations under the HMR and not enforceable. However, note that we have received and approved a petiton [P-1626] to incorporate by reference CGA Pamphlet C-1 in a future rulemaking.

I hope this information is helpful. If you have further questions, please contact this office.


Dirk Der Kinderen
Acting Chief, Standards Development Branch
Standards and Rulemaking Division

180.205(g)(3)(i), 180.205(g)

Regulation Sections

Section Subject
180.205 General requirements for requalification of specification cylinders