Introduction; Scope And Definitions; Flammable / Pyrophoric Materials - Edwards GXS Instruction Manual

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Introduction

1.1

Scope and definitions

This manual provides installation, operation and maintenance instructions for the GXS vacuum pump accessories and
should be used in conjunction with the GXS Dry Pumping System Instruction Manual - M588-00-880. You must use the
GXS vacuum pumping system accessories as specified in this manual.
Read this manual and the GXS Dry Pumping System Instruction Manual - M588-00-880 before you install or use the GXS
vacuum pumping system accessories. Important safety information is highlighted as WARNING and CAUTION
instructions; you must obey these instructions. The use of WARNINGS and CAUTIONS is defined below.
Warnings are given where failure to observe the instruction could result in injury or death to
people.
Cautions are given where failure to observe the instruction could result in damage to the equipment, associated
equipment and process.
The units used throughout this manual conform to the SI international system of measurement.
1.2

Flammable / pyrophoric materials

You must obey the instructions and take note of any precautions given below to ensure that
pumped gases do not enter their flammable ranges.
When flammable or pyrophoric materials are present within the pump there may be additional risks that the user is
responsible for assessing and managing as part of the entire process system installation. The severity of the risks and
the necessary control measures will depend largely on whether the process system exhaust is in the flammable
region, if this is part of normal operation, or if it might only occur under rare conditions. The additional risks arise
because all dry pumps must be considered a potential source of ignition due to the heat of compression, or possibly
friction. If ignition occurs then the following may happen:
High pressures could occur within the pump and may not be contained.

A flame front could travel back up the foreline.

A flame front could travel downstream from the exhaust of the pump.

Industry best practice suggests that the following measures will reduce the risks of pumping flammable mixtures and
pyrophoric materials, but it is the responsibility of the user to carry out a risk assessment and take appropriate
measures:
Do not allow air to enter the equipment.

Ensure that the system is leak tight.

Ensure that gases in the pump do not enter the flammable range. This may be achieved by diluting gases in

the pump by supplying sufficient inert gas purge. For example, dilution with nitrogen to below one quarter
Lower Explosive Limit (LEL) or, if that is not practical, to below 60 % Limiting Oxidant Concentration (LOC).
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WARNING
CAUTION
WARNING
M588-08-880 Issue D
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