18.2.1 At each Special Survey of the inert gas system, the inert gas generator,
scrubber and blower are to be opened out as considered necessary and examined. Gas
distribution lines and shut-off valves, including soot blower interlocking devices,
as well as interlocking features and positive isolation for tank isolation are to be
examined as considered necessary. The deck seal and non-return valve are to be
examined. Cooling water systems including the effluent piping and overboard
discharge from the scrubbers are to be examined. All automatic shut-down devices and
alarms are to be tested. The complete installation is to be tested under working
conditions on completion of survey.
18.2.2 When, at the request of an Owner, it has been agreed by the
Classification Committee that the Complete Survey of the inert gas systems may be
carried out on the Continuous Survey basis, the various items of machinery are to be
opened for survey in rotation, so far as practicable, to ensure that the interval
between consecutive examinations of each item will not exceed five years. In
general, approximately one fifth of the machinery is to be examined each year.
18.2.3 If any examination during Continuous Survey reveals defects, further
parts are to be opened up and examined as considered necessary by the Surveyor, and
the defects are to be made good to his satisfaction.