Use of Design Burst Test
Pipeline and Hazardous Materials Safety Administration · Feb 20, 1997 · Reference No. 97-0232
Interprets: 49 CFR § 178.33(a)
Reggie’s quick take
A company that makes DOT 2Q cans with a pressure relief device asked whether it can run the design burst test on a can with a plain, unscored end. The agency said yes, under § 178.33a-8(a). The company must still show that the relief device vents below the can's burst pressure at 130 F.
Written by AI (Claude) on Oct 22, 2026. Robots make mistakes and leave things out, so the letter below is what counts. Not legal advice.
This is in response to your letter requesting clarification on certain DOT 2Q specification requirements as prescribed in 49 CFR 178.33a. I apologize for the delay in responding and hope it has not caused you any inconvenience.
You state that your company manufactures a DOT 2Q can fitted with a pressure relief device. The pressure relief device design consists of a series of radial scores in the chuck wall and extends over the top of the double seam. The device vents the can when the pressure exceeds 180 psig, thus preventing burst. The can is design pressure tested with an identical, non-scored end to ensure that the body and bottom of the can meet the 270 psig minimum burst requirements. Based on your conversations with Messrs. James Jones and Gopala Vinjamuri, you requested confirmation of your understanding that testing a can with an identical non-scored end would satisfy the requirements of the regulations.
Your understanding is correct; the design burst test required by § 178.33a-8(a) may be performed on a can with a non-scored end. However, you must be able to demonstrate that the pressure relief device functions below the container burst pressure at 130 F.
A letter of interpretation applies the regulations to the facts the requester described. It isn’t a regulation and isn’t legal advice. The agency’s copy.