DRY SCREW VACUUM PUMPS
Exorbitantly priced, these pumps are imported. They are ideally used in clean applications. Excellent performance till there is a breakdown! Breakdowns are time consuming, costly and a lot of times the local suppliers are not able to handle major repairs thus resulting in scrapping of the pump.
For High Vacuum Distillations / Drying, it is absolutely necessary to maintain consistent High vacuum throughout the process duration. A drop in vacuum will see the process temperature and duration increase substantially. Also the final product could be susceptible to charring/burning or decomposition due to the drop in vacuum.
Secondly the vacuum systems are susceptible to corrosion and resultant heavy and expensive maintenance if the vapors are corrosive.