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I removed the backing pumps for TP2 and TP3 today to test ultimate pressure and determine if they need a tip seal replacement. This was done with Jon backing me on Zoom. We closed off TP3 and powered down TP3 and the auxilliary pump, in order to remove the forepumps from the exhaust line.
- Close V1
- Close V5
- Turn off TP3
- Turn off aux dry pump (manually)
- Once the PTP3 foreline pressure has come up to atmosphere, you can disconnect the TP3 dry pump and cap the exhaust line with a KF blank.
- Restore the vac configuration in reverse order: dry pump ON, TP3 ON, open V5, open V1
Once pumps were removed I connected a Pirani gauge to the pump directly and pumped down, results as follows:
TP2 Forepump (Agilent IDP 7):
- Ultimate Pressure: 123 mtorr
- Hours: 10903
TP3 Forepump (Varian SH 110):
- Ultimate pressure: ~70 torr
- Hours: 60300
TP3 forepump defintely needs a new tip seal, and while the pressure on TP2 Forepump was good there was a significant amount of particulate that came out of the exhaust line, so a new tip seal might not be needed but it is recommeded.
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