Section 5 Refrigerant detection systems

5.1.1 A fixed refrigerant detection system is to be provided in the refrigerating machinery compartment or space, the discharge pipes from pressure relief valves, ventilation outlet ducts, and the cargo chambers, where appropriate.

5.1.2 The alarm system is to comply with the requirements of Pt 6, Ch 1 Control Engineering Systems and, as a minimum requirement, the system is to activate at a low-level concentration to give warning of refrigerant leaks, and a high-level concentration corresponding to the refrigerant's safe occupational level.

5.1.3 Detection equipment is to be so designed that it may be readily tested and calibrated, and failure of the equipment is to initiate an alarm.

5.1.4 The location of the detectors is to be determined relative to the layouts of the individual compartments and machinery spaces and are to be indicated on the plan submission.

5.1.5 For carbon dioxide systems, spaces such as machinery rooms, storage compartments, production areas on fishing vessels and valve stations, where leakage may occur, are to be fitted with detectors. Welded pipelines passing through passageways or access ducts are not considered possible leakage areas.

5.1.6 Audible and visual alarms are to be activated, located both inside and outside the affected space. The alarms are to be readily identifiable and be visible and audible in all locations within the space housing the refrigeration equipment.

5.2.1 A fixed detector system for ammonia is to comply with the requirements contained in Pt 6, Ch 3, 5.2 Ammonia vapour detection and alarm equipment 5.2.2.

5.2.2 The location of the detectors is to be determined relative to the layouts of the individual spaces and are to be indicated on the plan submission required by Pt 6, Ch 3, 1.2 Plans and particulars.

5.2.3 Ammonia vapour detectors are to be provided in the refrigeration machinery compartment, associated access ways, the exhaust duct, the ammonia store room and the discharge pipes from pressure relief valves.

5.2.4 Sufficient detectors are to be provided to monitor the total areas of the above spaces.

5.2.5 For vapour detection in relief valve discharge pipes, see Pt 6, Ch 3, 4.15 Overpressure protection devices 4.15.4.

5.2.6 Details of the refrigerant detector set points and operational philosophy are to be submitted for consideration.