Page 103 - International safety guide for oil tankers and terminals

GENERAL HAZARDS FOR SHIP AND TERMINAL

In view of the ready availability and widespread use of such equipment,
appropriate measures should be taken to prevent its use within hazardous
---ใช้เพื่อการศึกษาเท่านั้น---
areas. Personnel must be advised of the prohibition of non-approved
equipment, and terminals should have a policy for informing visitors of the
potential dangers associated with the use of portable electrical equipment.
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
Terminals should also reserve the right to require any non-approved items of
equipment to be deposited at the entrance to the port area or other
appropriate boundary within the terminal.

4.4 Management of Electrical Equipment and
Installations in Dangerous Areas

4.4.1 General
This Section describes the different approaches to the classification of
dangerous areas on board tankers and of hazardous areas in terminals with
regard to electrical installations and equipment. General guidance is given on
the safety precautions to be observed during maintenance and repair of
electrical equipment. It should be noted that the standards for electrical
equipment and its installation are considered to fall outside the scope of this
Guide.

ึ
4.4.2 Dangerous and Hazardous Areas

4.4.2.1 Dangerous Areas in a Tanker

In a tanker, certain areas/spaces are defined by international convention,
flag administrations and classification societies as being
dangerous/hazardous for the installation or use of electrical equipment
either at all times or during specific periods such as loading, ballasting,
tank cleaning or gas freeing operations.

Definitions of dangerous areas on tankers, detailed in the classification
society rules, are derived from recommendations by the International
Electrotechnical Commission (IEC) as to the types of electrical equipment
that can be installed in them. It should be noted that for terminals the IEC
definitions follow a rigid classification based on a zonal concept (see
Section 4.4.2.2 below).

4.4.2.2 Hazardous Areas at a Terminal
At a terminal, account is taken of the probability of a flammable gas
mixture being present by grading hazardous areas into three zones. The
IEC classifies hazardous areas into zones based upon the frequency of
the occurrence and duration of an explosive gas atmosphere as follows:
Zone 0
A place in which an explosive atmosphere consisting of a mixture with
air of flammable substances in the form of gas, vapour or mist is
present continuously or for long periods or frequently.

Zone 1
A place in which an explosive atmosphere consisting of a mixture with
air or flammable substances in the form of gas, vapour or mist is likely
to occur in normal operation occasionally.

© ICS/OCIMF/IAPH 2006 69