Hi there, I have been doing some research about vacuum system setup and I've seen the setup shown in the attachment. Pressure: P1a, P1b, P2a, P2b Throughput/gas flow: Q1, Qs Pump speed: Sp (pumping speed of the pump) Conductance:Ca, Cb, C Some papers have assumed that P2a = P2b, but it seems to me that will only work if Ca = Cb = 0. If Ca and Cb exist: P2a=(Q1+Qs)/Sa 1/Sa=(C+Ca)+1/Sp and P2b=(Q1+Qs)/Sb 1/Sb=1/(C+Cb)+1/Sp So to make P2a = P2b, Ca = 1 - Cb. Is that right? Or am I missing something? Thank you very much!