46 C.F.R. § 39.20-3 Cargo gauging system—TB/ALL.
Title 46 - Shipping
(a) Each cargo tank of a tank vessel that is connected to a vapor collection system must be equipped with a cargo gauging device which: (1) Provides a closed gauging arrangement as defined in §151.15.10 of this chapter that does not require opening the tank to the atmosphere during cargo transfer; (2) Allows the operator to determine the liquid level in the tank for the full range of liquid levels in the tank; (3) Indicates the liquid level in the tank at the location where cargo transfer is controlled; and (4) If portable, is installed on the tank during the entire transfer operation. (b) Except when a tank barge complies with §39.20–9(a) of this part, each cargo tank of a barge must have a high level indicating device that: (1) Provides a visual indication of the liquid level in the cargo tank when the cargo level is within 1.0 meter (3.28 feet) of the tank top; (2) Has the maximum liquid level permitted under §39.30–1(e) of this part at even keel conditions conspicuously and permanently marked on the indicating device; and (3) Is visible from all cargo control areas on the tank barge.
Title 46: Shipping
PART 39—VAPOR CONTROL SYSTEMS
Subpart 39.20—Design and Equipment
§ 39.20-3 Cargo gauging system—TB/ALL.
