15.19 Overflow control
Clasification Society 2024 - Version 9.40
Statutory Documents - IMO Publications and Documents - International Codes - IBC Code - International Code for the Construction and Equipment of Ships Carrying Dangerous Chemicals in BulkAmended by Resolution MEPC.225(64) - Chapter 15 Special requirements - 15.19 Overflow control

15.19 Overflow control

  15.19.1 The provisions of this section are applicable where specific reference is made in column o in the table of chapter 17, and are in addition to the requirements for gauging devices.

  15.19.2 In the event of a power failure on any system essential for safe loading, an alarm shall be given to the operators concerned.

  15.19.3 Loading operations shall be terminated at once in the event of any system essential for safe loading becoming inoperative.

  15.19.4 Level alarms shall be capable of being tested prior to loading.

  15.19.5 The high-level alarm system required under 15.19.6 shall be independent of the overflow-control system required by 15.19.7 and shall be independent of the equipment required by 13.1.

  15.19.6 Cargo tanks shall be fitted with a visual and audible high-level alarm which complies with 15.19.1 to 15.19.5 and which indicates when the liquid level in the cargo tank approaches the normal full condition.

  15.19.7 A tank overflow-control system required by this section shall:

  1. .1 come into operation when the normal tank loading procedures fail to stop the tank liquid level exceeding the normal full condition;

  2. .2 give a visual and audible tank-overflow alarm to the ship's operator; and

  3. .3 provide an agreed signal for sequential shutdown of onshore pumps or valves or both and of the ship's valves. The signal, as well as the pump and valve shutdown, may be dependent on operator's intervention. The use of shipboard automatic closing valves shall be permitted only when specific approval has been obtained from the Administration and the port State authority concerned.

  15.19.8 The loading rate (LR) of the tank shall not exceed:

U = ullage volume (m3) at operating signal level;
t = time(s) needed from the initiating signal to fully stopping the cargo flow into the tank, being the sum of times needed for each step in sequential operations such as operator's responses to signals, stopping pumps and closing valves;
= and shall also take into account the pipeline system design pressure.

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