Page 30 - International safety guide for oil tankers and terminals

INTERNATIONAL SAFETY GUIDE FOR OIL TANKERS AND TERMINALS

Packaged cargo
Petroleum or other cargo in drums, packages or other containers.
or lead alkyls, as minor constituents.ึกษาเท่านั้น---
Pellistor
An electrical sensor unit fitted in a flammable gas detector for measuring hydrocarbon
งานห้องสมุด ศูนย์ฝกพาณิชย์นาวี
vapours and air mixtures to determine whether the mixture is within the flammable
range.

Permit (to work)
A document issued by a Responsible Person which allows work to be performed in
compliance with the ship’s Safety Management System.

Permit to Work system
A system for controlling activities that expose the ship, the terminal, personnel or the
environment to hazard. The system will provide risk assessment techniques and apply
them to the varying levels of risk that may be experienced. The system should conform
to a recognised industry guideline.

Petroleum
Crude oil and liquid hydrocarbon products derived from it.

Petroleum gas
cargo being carried.การศ
A gas evolved from petroleum. The main constituents of petroleum gases are
hydrocarbons, but they may also contain other substances, such as hydrogen sulphide

Phase of oil ึ
Oil is considered to have three phases in which it can exist depending on the grade of
Pressure surge้เพื่อ
oil and its temperature. The three phases are the solid phase, the liquid phase and the
vapour phase. The phases do not exist in isolation and operators must manage the
carriage of oil with an understanding of the combinations of the phases of oil in the

Pour point
---ใช A sudden increase in the pressure of the liquid in a pipeline brought about by an abrupt
The lowest temperature at which a petroleum oil will remain fluid.

change in flow rate.

Pressure/vacuum relief valve (P/V valve)
A device that provides for the flow of the small volumes of vapour, air or inert gas
mixtures caused by thermal variations in a cargo tank.

Pump purging
The operation of clearing liquid from submerged pumps.

Purging
The introduction of inert gas into a tank already in the inert condition with the object of
further reducing the existing oxygen content and/or reducing the existing hydrocarbon
gas content to a level below which combustion cannot be supported if air is
subsequently introduced into the tank.

Pyrophoric iron sulphide
Iron sulphide capable of a rapid exothermic oxidation causing incandescence when
exposed to air and potential ignition of flammable hydrocarbon gas/air mixtures.

xxx © ICS/OCIMF/IAPH 2006