Well...I'm really ashamed to ask this question but.....
When raising my lever to pull a shot, is preinfusion automatic in the top position?...or do I need to pause the lever in the middle position (pretty much extended horizontal) for a few seconds?...oh...I'm SO ashamed

EDIT...actually, the "middle" position is actually not horizontal, but around 45 degrees...anyway...I think I answered my own question, as i tried raising the lever up a bit...no water, so I guess it needs to go all the way up to start the pre-infuze?

The mid-position opens the valve connecting the HX and brew chamber without engaging the pump. Since the Anita is a vibration pump pourover machine, some water may dribble out under residual / expansion pressure (see patent explanation and schematics if you really want to understand the mechanics). If it were plumbed in, you could have the mid-position allow passive preinfusion under line pressure, though I'm not aware of any prosumer E61 sold that way from the factory. I believe that's on Chris and Terry's list of modifications for the Monster Bricc project.

PS: Pressure profiles, preinfusion and the forgiveness factor graphically demonstrates what the E61 mechanism accomplishes:


Pressure profile of Brewtus (E61 with expansion chamber),
Elektra A3 (proprietary design), and Valentina (E61 with no expansion chamber)

HB wrote:The mid-position opens the valve connecting the HX and brew chamber without engaging the pump. Since the Anita is a vibration pump pourover machine, some water may dribble out under residual / expansion pressure (see patent explanation and schematics if you really want to understand the mechanics). If it were plumbed in, you could have the mid-position allow passive preinfusion under line pressure, though I'm not aware of any prosumer E61 sold that way from the factory. I believe that's on Chris and Terry's list of modifications for the Monster Bricc project.

My plumbed-in factory Bricc behaves this way - if I move the lever to the upper-middle position, it opens the valve but has not yet hit the pump microswitch, and water flows out of the grouphead under line pressure. All I had to do to make this work was to adjust the microswitch so that it engaged at a higher lever position than when I got it.

HB wrote: If it were plumbed in, you could have the mid-position allow passive preinfusion under line pressure, though I'm not aware of any prosumer E61 sold that way from the factory.

Does it matter if the pump is vibe or rotary? By that I mean, does either type of pump stop the flow of water when the pump is off?

Some rotary machines allow flow-through, which I found out accidently when I took apart the grouphead of the Elektra A3 before turning off the water (one of those "What the...!?!" moments ). Direct plumb vibration pumps don't allow flow-through; for that matter, the Andreja Premium conversion kit and my own installation include a cutoff solenoid on the water inlet to reduce the risk of leakage and prevent backflow.

I believe most city codes will mandate a solenoid to isolate the machine from the city water supply. In the event the city loses water pressure, they do not want any backwash into the mains.

I just added a float valve to my tank (Isomac with a vibratory pump) that way I can move the machine and still use it as a pour over if needed.

cannonfodder wrote:I just added a float valve to my tank (Isomac with a vibratory pump) that way I can move the machine and still use it as a pour over if needed.

The Andreja Premium direct-plumb conversion kit allows you to switch back and forth simply by moving the silcone tubing inlet from the tank to the barbed fitting (it's the silver fitting atop the brass solenoid below). For that to work, the inlet pressure must be very low so the tubing doesn't pop off. Quickmill smartly included a pressure gauge and pressure regulator plus the solenoid's piggyback hookup for the pump leads. Sure would be nice if more manufacturers had ready-made conversion kits like this...


Andreja Premium conversion kit; inset shows the external hookup

cannonfodder wrote:I believe most city codes will mandate a solenoid to isolate the machine from the city water supply. In the event the city loses water pressure, they do not want any backwash into the mains.

Not necessarily. The codes just want to prevent backwash, as you say, and that's generally much less expensive to provide with a one-way check valve than with a solenoid.

Best,
David

I can see how in an HX machine (with vibe pump or with a reservoir) the middle position on the E61 would not be under pressure. However, in a dual boiler machine with an E61 like the Brewtus, does the brew boiler water flow through the E61, and if so, what stops the middle position from exposing the puck to water that is at brew boiler pressure?

Actually both systems (HX and dual boiler) are under some pressure due to thermal expansion. You'll notice that the brew gauge on HX E61 lever-type espresso machines will read zero immediately after a shot and then slowly creep upward. Brewtus doesn't have a brew gauge, but it should behave similarly. This residual pressure can push out some water at the mid-way position, but not enough to preinfuse per se ("partially wet the top of the puck" is more accurate).


Brewtus' brew water pathway shown in red; thermosyphon return (T) in blue