I bought the shell of an older La San Marco 80-2 that was setup for gas, but had electric pump and volumetric dosing. The weird thing is that the volumetric dosing was delivered using a hydraulic piston with switches to measure the piston displacement volume and hence the dose.

Has anyone else seen this before?


The picture is taken looking in at the back of the group head (on the left) and the volumetric dosing cylinder is on the right (its a big one)

Gota say, the wiring that is involved to provide volumetric dosing in the way is pretty substantial when compared to how easy it is with a flowmeter.

Dane: I've never seen this machine before but I can tell you that limit switches are used all over industry, in many many shapes, types and sizes. I assume there is a cam on a shaft attached to the piston. That should make it easy to adjust and those small "micro switches" are easy to find (most types) and mostly inexpensive. Lots of wiring but if it is intact and correctly connected it won't (shouldn't) be a problem. Do you have a diagram?
KDM

I don't have any documentation unfortunately.

Figured that it would be quite uncommon, but I could not find a mention of any pre flowmeter dosing systems, so thought it was pretty cool. The workmanship on the cylinders is good. The base of the solenoid you can see on the lid is actually moulded into the lid of the cylinder rather than boletd on. Also, I'm not sure if it is meant to be like this, but the joint between the cylinder wall and ends is metal/metal without any gasket which if deigned that way is interesting.