▪ Use an inert gas purge into the pump gas ballast connecon to prevent the
condensaon of ammable vapours within the pump mechanism and exhaust
pipeline.
5.1.2 Gas purges
WARNING:
If using inert gas purges to dilute dangerous gases to a safe level, ensure that the
pump is shut down if an inert gas supply fails.
WARNING:
Obey the instrucons and take note of the precauons given below to ensure that
pumped gases do not enter their ammable ranges.
Switch on the inert gas purge to remove air from the pump and the exhaust pipeline
before the process starts. Switch o the purge ow at the end of the process only aer
any remaining ammable gases or vapours have been purged from the pump and
exhaust pipeline.
If liquids that produce ammable vapours could be present in the pump foreline, then
the inert gas purge to the pump should be le on all the me this liquid is present.
Flammable liquids could be present in the foreline as a result of condensaon or may be
carried over from the process.
When calculang the ow rate of inert gas required for diluon, consider the maximum
ow rate for the ammable gases/vapours that could occur. For example, if a mass ow
controller is used to supply ammable gases to the process, assume a ow rate for
ammable gases that could arise if the mass ow controller is fully open.
Connually measure the inert gas purge ow rate: if the ow rate falls below that
required, stop the ow of ammable gases or vapours into the pump.
Note:
We recommend obtaining and reading the Vacuum Pump and Vacuum System Safety
manual (publicaon number P40040100), available from us or the supplier.
5.2 Gas-ballast control
Use the gas-ballast control (Figure: General view of the pump on page 11) to change the
ow of gas-ballast into the low vacuum stage of the pump and to provide an addional
oil-feed to the pump mechanism.
Use the gas-ballast control closed:
▪
To achieve ulmate vacuum.
▪
To pump dry gases.
Turn the gas-ballast control by up to two turns an-clockwise to introduce an addional
oil-feed to the pump mechanism. We recommend doing this when pumping high
throughputs of dry gases.
Page 32
A34310880_T - Operaon
To Next Page
Loading...
Need help?
General
