46 C.F.R. § 64.69 Location of the pressure relief device.
Title 46 - Shipping
A pressure relief device must be— (a) Accessible for inspection and repair before stowage of the tank; and (b) Attached so that escaping gas does not impinge on the tank or framework.
Title 46: Shipping
PART 64—MARINE PORTABLE TANKS AND CARGO HANDLING SYSTEMS
Subpart C—Pressure Relief Devices and Vacuum Relief Devices for MPTs
§ 64.69 Location of the pressure relief device.

