Hi all, I have a vacuum chamber which is consistently pumped out by a mechanical pump at the downstream end and is fed nitrogen at the upstream end. The path of the nitrogen is as follows: A mass flow controller regulates 150 SCCM flowing at all times. The N2 flows through several feet of 1/4 inch tube. The N2 then enters the reactor which is a 2.75 inch tube. The pressure is read by a gauge in the 2.75 inch tube. The N2 then flows to the pump. Like this: MFC (150 SCCM) --> 1/4" tube --> 2.75" tube (w/ pressure gauge) --> pump My question is, lets say the pressure is read to be 1 torr in the 2.75 inch tube, is the pressure the same in the 1/4 inch tube? I am familiar with the bernoulli equation but unsure if that applies here, Thanks for any feedback!