Interpretation Response #25-0136
Below is the interpretation response detail and a list of regulations sections applicable to this response.
Interpretation Response Details
Response Publish Date:
Company Name: Linde Gas and Equipment
Individual Name: Mark Hammond
Location State: IN Country: US
View the Interpretation Document
Response text:
February 24, 2026
Mark Hammond
Linde Gas and Equipment
3625 S. Main Street
South Bend, IN 46614
Reference No. 25-0136
Dear Mr. Hammond:
This letter is in response to your October 8, 2025, email requesting clarification of the Hazardous Materials Regulations (HMR; 49 CFR Parts 171-180) applicable to leakage testing on cargo tanks. You perform annual visual and leakage inspections on cargo tanks containing liquefied petroleum gas (LPG) in which you apply a leak-detecting fluid to find bubbles at fittings, valves, and welds. You ask about a test and inspection form that your company uses to record requalification activity. The form includes a section to record performance of a leakage test and two boxes to indicate a "hydrostatic" or "pneumatic" test. The report contains an additional section to indicate performance of a leakage test section which includes fields to indicate the fluid used and pressure during a leakage test. Specifically, you ask whether you should leave both the hydrostatic or pneumatic boxes blank and instead fill out the second leakage test portion of the form with LPG listed as the test medium (i.e., the fluid used).
The HMR neither requires use of a particular form nor specifies a format. Therefore, this Office cannot provide specific instructions regarding how to fill out the proprietary form you provided and described in your letter. You need only record and maintain a report of tests or inspections in accordance with § 180.417(b).
It is the opinion of this Office that not selecting either "hydrostatic" or "pneumatic" when recording a leakage test is appropriate. Pneumatic and hydrostatic tests are "pressure tests" as specified in § 180.407(g). The inspection method you described conforms to the "leakage test" outlined in § 180.407(h), therefore you should only record the completion of a leakage test. Furthermore, this Office suggests that the second portion of the form should also remain blank unless you are providing information related to Environmental Protection Agency (EPA) Method 27 Vapor Tightness Test (K-EPA27).
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
180.417(b)
Regulation Sections
| Section | Subject |
|---|---|
| 180.417 | Reporting and record retention requirements |