connecon (at the standard pressure switch or the opon ow meter). Nitrogen and
clean dry air are suitable purge gases for the dry pumping systems. To use a dierent
purge gas, please contact us.
Check visually that the dial pressure gauge and rotameter (if installed) is not damaged
when installing the dry pumping system.
Note:
Refer to Purge data on page 18 for the purge gas supply requirements.
3.4.1 Flammable/pyrophoric materials
WARNING:
Obey the instrucons and take note of any precauons given below to ensure that
pumped gases do not enter their ammable ranges.
When ammable or pyrophoric materials are present within the pump there may be
addional risks that the user is responsible for assessing and managing as part of the
enre process system installaon. The severity of the risks and the necessary control
measures will depend largely on whether the process system exhaust is in the
ammable region, if this is part of normal operaon, or if it might only occur under rare
condions. The addional risks arise because all dry pumps must be considered as
potenal source of ignion due to the heat of compression, or possibly fricon. If
ignion occurs then the following may happen:
▪
High pressures could occur within the pump and may not be contained.
▪
A ame front could travel back up the foreline.
▪ A ame front could travel downstream from the exhaust of the pump.
Industry best pracce suggests that the following measures will reduce the risks of
pumping ammable 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 dry pumping system is leak‑ght.
▪ Ensure that gases in the pump do not enter the ammable range. This may be
achieved by dilung gases in the pump by supplying sucient inert gas purge. For
example, diluon with nitrogen to below one quarter Lower Explosive Limit (LEL)
or, if that is not praccal, to below 60% Liming Oxidant Concentraon (LOC).
▪
The gas module supplied with the pump is not intended to perform a safety
funcon. Users may need to consider adding appropriate measures to monitor the
ow of purge gas (for example, external sensors). The dry pumping systems that
are ed with light‑duty gas module must not be used on applicaons pumping
ammable or pyrophoric materials.
For further informaon please refer to publicaon number P40040100, applicaons
note 'Pumping Flammable Gases' P4100090 or contact us.
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