46 C.F.R. § 64.65
Vacuum relief device.
Cite as 46 C.F.R. § 64.65 (2026)
(a) Each MPT that is designed for an external pressure of less than 7.5 psig must have a vacuum relief device.
(b) A vacuum relief device for an MPT must—
(1) Open at an external pressure of not less than 3 psig; and
(2) Have an opening with a cross-section of 0.44 square inch or more.
[CGD 84-043, 55 FR 37410, Sept. 11, 1990]