TP3 turbo pump's dry-foreline pump was replaced.
How to do it:
The pump should be replaced when it's performance <1.0 - 1.3 Torr
Set up valve configuration as shown at Atm1: close in this order VAEE, VASV, VABS, VASV, VASE, VA6 and V5,
Turn TP3 off at it's controller in the rack. Wait till is stops, so you can read 760 Torr at TP3 foreline gauge
Disconnect intake, exhaust vacuum seals and replace pump. Reconnect vacuum fitting and start it up.
Confirm operational details on the front of the controller: 50 K_RPM, 0.2A and <100 mTorr
Reset valves in reverse order
PS: the average life of the tip seal on the Varian SSH-110 dry-pump is about 1 year
This pump " ser LP1007L556 " seal made new record of 668 days: thanks to Bob Taylor who is replacing these seals