Diffusion pumps are often considered the wonders of the vacuum pumping world. They are simple to operate, have no moving parts, need little maintenance and are relatively inexpensive.
However, even diffusion pumps have a few do’s and don’ts. Below is a list of 12 things every vacuum furnace user should avoid when using a diffusion pump.
Diffusion Pump Don’ts
- Do not use substitute pumping fluids.
- Do not attempt to open drains or fill plugs if the diffusion pump is under vacuum (especially when it is hot).
- Do not leave the inlet valve open when leaks or continuous gas generation from sources within the furnace system cause pressure higher than two microns near the pump inlet.
- Do not use heaters higher than the recommended power rating.
- Do not operate the diffusion pump when the fluid level is low.
- Do not operate the pump without cooling water circulating in the coils or without the proper backing pump. For large installations, dual-protection systems are advisable. Thermostatic devices will usually protect the pump in case of a lack of fluid or loss of water, but failure of control circuitry is always possible.
- Do not override safety devices.
- Do not admit atmospheric air to the pump when the diffusion pump is hot.
- Do not turn the pump’s power on unless the pump is properly charged with fluid and evacuated below 0.5 Torr.
- Do not contaminate the pump with explosive vapors, powders or materials that may react with the recommended pumping fluids.
- Do not operate the quick-cool coil If the pump is out of service. Harmful condensate may collect on the heater terminals.
- Do not leave the pump cooling water on when the pump is not in operation and is exposed to atmosphere. Leaving it on can result in moisture condensation inside the pump.
For any questions related to vacuum furnace pumping systems, call Ipsen Customer Service at 1-844-GO-IPSEN.