Changing rotary pump oil

[mjh32586]

I'm new to gc/ms and I have a few questions about changing the rotary pump oil. I was told that the oil for our rotary pump needs to be changed every 3000 hours of operation. With this said, is that just recommended or does it really make a huge difference? I'm curious to know what exactly happens if I would wait until 5000 hours and what effects it has in general if it is not changed often enough.

Thanks in advance!

[Bigbear]

I would follow the factory times. In our case ( Agilent ) they say to change every 6 months.
It's quite easy just vent the system ( you don't need to open the vacuum chamber) turn off the pump, drain, re fill and then pump down.

[Don_Hilton]

Potential problems: Figure on accumulation of degredation products and other stuff in the oil, which could result in 1) damage to seals and parts in the pump (shorter pump life) 2) if the degredation products have some volatility bud will condense in the compression phase of the pump cycle, degraded foreline pressure and 2) if the degredation products are sufficiently volatile, migration from the pump, upstream to the spectrometer - increasing noise in the spectrometer. The most likely is shorter pump life. The last would require signifcant abuse to the oil, but having worked as a service engineer, if I can scare people into taking care of an instrument, I'll do it! (I hate seeing an abused instrument that need to be rebuilt or discarded simply because someone did not take care of it properly.)

[mjh32586]

Thanks Don! I changed it this morning so no more abused instrument The manufacturer said 3000 hours but I ran it for 3800 hours so I'm hoping that won't cause any issues but I was curious to know what effects it has on the instrument.