If an MPT is designed with a filling or discharge connection in the bottom, the connection must be fitted with a bolted blank flange, threaded cap, or similar device to protect against leakage of the product, and a manually operated valve that is located—
(a) Inside the tank and operated outside the tank; or
(b) Outside the tank but as close to it as practicable.
source: CGD 73-172, 39 FR 22950, June 25, 1974, unless otherwise noted.
cite as: 46 CFR 64.35