What you have is an electric releaser jar for the pipeline. The pump on the bottom of the jar is not a vacuum pump it is a transfer pump that took milk away from the glass jar after it gets about 1/3 full. There is a electric sensor in the middle of that jar that comes down from the top. When the milk hit the sensor the pump would turn on almost emptying the jar. This always allowed vacuum to the pipeline, thus never having to relieve vacuum to empty the jar.
There is a stainless elbows and pipe attached to that pump that would send it to the milk tank. That appears to missing in your pics. They may be laying around in that milkhouse or someone needed them. The two toggle switches on the control panel........the right one would manually trip the pump in that photo on for a specified number of seconds. The left one would turn on the vacuum pump and vacuumize the whole system. We have the same thing in our dairy barn and is currently in use.
Mark
Where we made syrup long before the trendies made it popular, now its just another commodity.
John Deere 4000, 830, and 420 crawler
1400 taps, 600 gph CDL RO, 4x12 wood-fired Leader, forced air and preheater. 400 gallon Sap-O-Matic vacuum gathering tank, PTO powered. 2500 gallon X truck tank, 17 bulk tanks.
No cage tanks allowed on this farm!