Page 161 - International safety guide for oil tankers and terminals

MANAGEMENT OF SAFETY AND EMERGENCIES

operations, the permit should be withdrawn or cancelled. On completion
of the operation, all safety checks should be carried out once more and
---ใช้เพื่อการศึกษาเท่านั้น---
the permit re-approved or a new procedure developed.

Where Hot Work involves entry into an enclosed space, the procedures
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
outlined in Chapter 10 for enclosed space entry should be followed. A
compartment in which Hot Work is to be undertaken should be cleaned
and ventilated. Particular attention should also be given to the condition of
any adjacent spaces.

Adjacent fuel oil bunker tanks may be considered safe if tests give
readings of less than 1% LFL in the vapour space of the bunker tank. No
Hot Work should be carried out on bulkheads of bunker tanks, or within
500 mm from such bulkheads, unless that tank has been cleaned for Hot
Work.

Adjacent ballast tanks and compartments, other than cargo tanks, should
be checked to ensure they are gas free and safe for Hot Work. If adjacent
ballast tanks and compartments are found to contain hydrocarbon liquid
or vapours, they should be cleaned and gas freed or inerted.

9.4.4.2 Hot Work in Cargo Tanks
To clean the work area, all sludge, cargo-impregnated scale, sediment or
ึ
other material likely to give off flammable vapour should be removed. The
extent of the cleaned area should be established following a risk
assessment of the particular work to be carried out. Special attention
must be given to the reverse side of frames and bulkheads. Other areas
that may be affected by the Hot Work, such as the area immediately
below the work location, should also be cleaned.

Table 9.1 provides guidance on the safe distance for areas to be cleaned
and represents minimum requirements that may need to be extended,
based on the output of the risk assessment. Cleaning distances are
based on the type of work being carried out and the height above the
tank bottom.

Consideration should be given to using fire resistant blankets or putting a
water bottom in the tank to prevent falling sparks coming into contact with
paint coatings.

All interconnecting pipelines to other compartments should be flushed
through with water, drained, vented and isolated from the compartment
where Hot Work will take place. Cargo lines may be subsequently inerted
or completely filled with water, if considered necessary.

Operator’s Side Opposite Side
Height of
Work Area Gas Cut Welding Gouging Gas Cut Welding Gouging
0-5 metres 1.5 m 5.0 m 4.0 m 7.5 m 2.0 m 2.0 m
5-10 metres 1.5 m 5.0 m 5.0 m 10.0 m 2.0 m 2.0 m

10-15 metres 1.5 .0 m 7.5 m 15.0 .0 .0 m
>15 metres 1.5 .0 m 10.0 m 20.0 .0 .0 m

Table 9.1 – Radius of areas to be cleaned in preparation for Hot Work in tanks

© ICS/OCIMF/IAPH 2006 127