Hey guys,
This is my first post after reading these forums for months. After tons of research, I upgraded from a Silvia V3 to an Expobar Brewtus IV-R and am loving it so far. (with Vario grinder)

I do not want to ask a question that has been asked before, but if I have, gladly point me to the correct post.

My question is an extension of the following thread which is now closed for comments: Expobar Over Pressure Valve

My own Brewtus IV-R was reporting a brew pressure of 7.5 with pump engaged and back flush in place. I followed Chris's instructions for setting the OPV to drip at 11 bar and then turn the rotary pump regulator down till front gauge registered 9 bar.

I have done this...somewhat. The issue now is the time it takes for the pressure to climb as follows:
1. Fully lift lever to brew position (with back flush in place)
2. Pressure climbs to about 7.5 bar during pre-infusion (5-6 seconds)
3. After 5-6 secs the pressure starts SLOWLY climbing and hits 9 bar at approx 15-20 secs.
4. Pressure continues to climb to about 10.5 bar by 45-50 secs then stabilizes.

Is this slow climb behavior normal? It seems to me reading the other posts about adjusting rotary pump brew pressure, that the pressure readings are a little bit more straightforward.

Chris or the guys from WLL, I would love your input since you are the gurus! Or anyone else who has come across this.

One last note...there are tons of posts about OPV adjustments on the site, but most of those are for vibration pumps. Before you post about me changing the OPV spring, realize I am talking about a rotary pump.

Thanks in advance for the ideas!!

This sounds normal. The brew pressure gauge is located before the E61 gicleur, so it will read slightly higher than the actual brew chamber pressure, but otherwise what you describe is typical E61 operation (slow pressure ramp for preinfusion). See Is there a purpose for the E61 middle brew lever position? and Why difference in pressure between blind filter and brewing? for more detailed explanations.

HB wrote:<snip, snip>

The final image shows the E61 lever in the brew position. The upper valve is held open by the orange cam. The valve at the bottom of the expansion chamber is held tightly closed by a spring. The spring above it holding the second valve closed is weaker; it will open at about 4 bars of pressure. It only takes a second or two for the brew chamber containing the orange cam to pressurize. As the pressure builds, water eeks pass the valve below the orange cam, allowing the pressure to drop. This action is the novelty claim of the E61 patent since the pressure is automatically lower as the expansion chamber fills. Once the lower chamber fills, the pressure equalizes in all chambers and the valve below the cam closes.



The familiar "whoosh" that follows the lever being lowered is water evacuating the brew chamber and expansion chamber. Again at rest, the expansion chamber and brew chamber are empty. Water continues to circulate along the jacket of the uppermost chamber as the thermosyphon re-establishes itself.

According to Jim at 1st-Line (the importer of the Vibiemme machines), and simply put, the only time the brew pressure gauge on these E-61 machines shows any accurate, or at east to say useful information, is when the brew function is engaged.

Matt,

Greetings from Winnipeg.

I'm sure you are enjoying your Brewtus IV-R.

I too bought one about a year ago. Perhaps we got it from the same place, zcafe.ca.

I'm also using the Vario grinder so our setups are similar indeed. If you are using the Bestmax water filter, that would be an eerie coincidence.

If you could Matt, send me an email to bewiebe@shaw.ca as I'd like to get your view on the machine.

I'm finding my Brewtus is losing temperature and it never used to do that. I'd like to see if your brand new machine is working similar.

Randy G. wrote:According to Jim at 1st-Line (the importer of the Vibiemme machines), and simply put, the only time the brew pressure gauge on these E-61 machines shows any accurate, or at east to say useful information, is when the brew function is engaged.

Randy and Jim are correct
I will
also add that:
IF the machine is plumbed in,
while the machine is TURNED OFF
the gauge will be giving you reading of your line pressure, also important so you do not stress the inlet valve etc etc