Hi J, I am also a new owner of an Expobar machine and recently did a pressure adjustment on mine. I do have a rotary pump, but I can tell you that while the pump is deadheaded(flush disk in place, and pump running) when I turn the adjustment the pressure changes immediately. The pump should be providing something like 15bar to the opv, and the opv is bleeding off the excess to regulate the pressure to where you set it.
On my machine there is no resivoir so the excess pressure comes out a little down spout below the discharge of the group head. When I am brewing a shot there is a continuous stream coming out there. On a machine with a resivoir it may be plumbed back into the resivoir. This is a great reference that helped me better understand the operation of these machines: http://www.home-barista.com/downloads/ExpobarParts01.pdf Hope that helps! Ryan -- You received this message because you are subscribed to the Google Groups "Brewtus" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/brewtus. For more options, visit https://groups.google.com/d/optout.
