39.20-9—Tank barge liquid overfill protection—B/ALL.
Each cargo tank of a tank barge must have one of the following liquid overfill protection arrangements.
(3)
Receives power from a facility and is fitted with a shore tie cable and a 120 volt 20 amp explosion-proof plug which meets:
(2)
Actuates an alarm and automatic shutdown system at the facility overfill control panel, or on the vessel to be lightered if a lightering operation, 60 seconds before the tank becomes 100 percent liquid full;
(4)
Consists of components which, individually or in series, will not generate or store a total of more than 1.2 V, 0.1 A, 25 mW, or 20 microjoules;
(i)
Configured with pins S2 and R1 for the tank overfill sensor circuit, pin G connected to the cabling shield, and pins N and T3 reserved for an optional high level alarm circuit meeting the requirements of this paragraph; and
(ii)
Labeled “Connector for Barge Overflow Control System” and with the total inductance and capacitance of the connected switches and cabling.
(2)
Relieves at a pressure higher than the pressure at which the pressure relief valves meeting the requirements of § 39.20-11 operate;
(3)
Limits the maximum pressure at the cargo tank top during liquid overfill, at the maximum loading rate for the tank, to not more than the maximum design working pressure for the tank; and
(4)
If the vessel is in ocean or coastwise service, has provisions to prevent opening due to cargo sloshing.
(d)
A rupture disk arrangement which meets paragraphs (c)(2), (c)(3) and (c)(4) of this section and is approved by the Commandant (CG-522).
[CGD 88-102, 55 FR 25446, June 21, 1990, as amended by CGD 95-072, 60 FR 50462, Sept. 29, 1995; CGD 96-041, 61 FR 50727, Sept. 27, 1996; USCG-2000-7790, 65 FR 58459, Sept. 29, 2000]