Logitech Ltd IU30 Impregnation Unit Operation and Maintenance ...
Logitech Ltd IU30 Impregnation Unit Operation and Maintenance ...
Logitech Ltd IU30 Impregnation Unit Operation and Maintenance ...
You also want an ePaper? Increase the reach of your titles
YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.
1.4.2 Gas-ballast control<br />
A652–01–880 Issue S<br />
To pump high vapour loads, gas-ballast is delivered into the pump to prevent condensation of the vapour carried by<br />
the pumped gases.<br />
Air can be introduced to the low vacuum stage through the gas-ballast valve. Alternatively, an inert gas such as<br />
nitrogen can be supplied through a suitable external valve.<br />
The gas-ballast control has three positions:<br />
� Closed (position ‘0’)<br />
� Low flow (position ‘I’)<br />
� High flow (position ‘II’).<br />
1.5 Construction<br />
The pump-shafts <strong>and</strong> rotors are made of high-grade cast-iron. The pump-body <strong>and</strong> oil-box are made from<br />
cast-aluminium. All surfaces of the pump which are exposed to the pumped gases are free from copper, zinc <strong>and</strong><br />
cadmium.<br />
Other materials of construction include fluorocarbon elastomer, nitrile, silicon, chemically-resistant polymers, nickel<br />
<strong>and</strong> stainless steel.<br />
© Edwards Limited 2007. All rights reserved. Page 5<br />
Edwards <strong>and</strong> the Edwards logo are trade marks of Edwards Limited.<br />
Introduction
Change language