U.S. Code of Federal Regulations
Regulations most recently checked for updates: Sep 16, 2025
A pressure relief device must be plainly and permanently marked with the—
(a) Set pressure rating;
(b) Rated flow capacity expressed as cubic feet of standard air (60 °F 14.7 psia) per minute and the pressure at which the flow capacity is determined;
(c) Manufacturer's name and identifying number; and
(d) Pipe size of inlet.