I use manifold here to describe a continuous enclosed volume that cannot be further segmented by valves. Pressure is not necessarily equal throughout a manifold due to conductance.
All of the valves on the 2100F vacuum system are ultimately electronically controlled, with the exception of V5 which is manually actuated by rotating the sample holder to insert a sample into the column. Solenoid valves are directly controlled by an electrical signal, while pneumatic valves have one or more associated solenoids that switch air pressure to actuate the valve. The 3-way solenoid valves used in this system have two ports connected through the valve body at all times, while a third port connection is gated through the valve. The vacuum diagram is topologically simplified to only show the gated connections.
