40m QIL Cryo_Lab CTN SUS_Lab TCS_Lab OMC_Lab CRIME_Lab FEA ENG_Labs OptContFac Mariner WBEEShop
  40m Log  Not logged in ELOG logo
Entry  Thu Jun 18 15:25:08 2020, Jordan, Update, VAC, TP2 and TP3 Forepump removal 
    Reply  Thu Jun 18 16:56:34 2020, Jordan, Update, VAC, TP2 and TP3 Forepump removal 
Message ID: 15409     Entry time: Thu Jun 18 15:25:08 2020     Reply to this: 15411
Author: Jordan 
Type: Update 
Category: VAC 
Subject: TP2 and TP3 Forepump removal 

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.

  1. Close V1
  2. Close V5
  3. Turn off TP3
  4. Turn off aux dry pump (manually)
  5. 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.
  6. 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.

ELOG V3.1.3-