Page 232 - International safety guide for oil tankers and terminals

INTERNATIONAL SAFETY GUIDE FOR OIL TANKERS AND TERMINALS

The Terminal Representative should be consulted to ascertain that
conditions on the jetty do not present a hazard and to obtain
---ใช้เพื่อการศึกษาเท่านั้น---
agreement that operations can start.
If craft are alongside the tanker, their personnel should also be notified
and their compliance with all appropriate safety measures should be
cleaned.มุด ศูนย์ฝกพาณิชย์นาวี
checked.
Additional considerations that apply when tanks have been inerted are
given in Section 7.1.6.12.

11.4.4 Gas Testing and Measurement

In order to maintain a proper control of the tank atmosphere and to check
the effectiveness of gas freeing, a number of gas measuring instruments
should be available on the ship. Section 2.4 provides details of these
instruments and Section 8.2 contains information on their use.

Atmosphere testing should be undertaken regularly during the gas freeing
operation to monitor progress.

Tests should be made at several levels and, where the tank is subdivided
by a swash bulkhead, in each compartment of the tank. In large
compartments, tests should be made at widely separate positions.
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On the apparent completion of gas freeing of any compartment, a period
of about 10 minutes should elapse before taking final gas measurements.
This allows relatively stable conditions to develop within the space.

If satisfactory gas readings are not obtained, ventilation must be
resumed.

On completion of gas freeing, all openings, except the tank hatch, should
be closed.

On completion of all gas freeing, the gas venting system should be
carefully checked, particular attention being paid to the efficient working
งานห้องส
of the pressure/vacuum valves and any high velocity vent valves. If the
valves or vent risers are fitted with devices designed to prevent the
passage of flame, these should also be checked and, if necessary,

11.4.5 Fixed Gas Freeing Equipment
Fixed gas freeing equipment may be used to gas free more than one tank
simultaneously, but must not be used for this purpose if the system is
being used to ventilate another tank in which washing is in progress.

Where cargo tanks are gas freed by means of one or more permanently
installed blowers, all connections between the cargo tank system and the
blowers should be blanked, except when the blowers are in use.

Before putting a fixed gas freeing system into service, the cargo piping
system, including crossovers and discharge lines, should be flushed
through with sea water and the tanks stripped. Valves on the cargo piping
system, other than those required for ventilation, should then be closed
and secured.

198 © ICS/OCIMF/IAPH 2006