Anyone here who wonders if an OPV (expansion valve) is essential on a direct plumbed HX Giotto?
I don't anymore.
I have been very near to TNB, Total Nervous Breakdown, this week.
Started, as I thought, after a very ambitious descaling.
Everything seemed to be normal in the beginning starting with a cold machine, water coming fine from brewhead with and without pump running. After heating finished with correct temp and pressure, the lever was very hard to move, almost impossible and no water was coming from brewhead even if I managed to operate the lever to correct position with severe violence.
Opened the top section up and found this:

and

After one week of thinking, mounting and demounting (10 times at least) and two trips to Gothenburg's most competent service-shop and back with new spare parts. Nothing helped!!

I had to start from the very beginning of this adventure and figure out what had happened, and YES!
I did start with descaling the OPV and tried with a new setpoint of opening. Too tight as it would show, it didn't open at all.
No room for thermal increasing, the bigger volume when heated pressed the E61's rubber sealing VERY hard and made it hard to operate the lever.
Demounting the OPV and losing a bit on the SP-screw solved all problems in minute.

I have been searching this fora and several others but found nothing on the subject of the importance and consequence of no OPV and hope this post can help someone sometime.

PS. I will celebrate this with my best barolo-wine to drink with dinner and VERY nice double espresso ristretto made on my favourite bean Monsooned Malabar + Old Brown Java.

I cannot speak for ECM
but last time this argument was brought to the attention of a well known Italian manufacturer
what I was told is that when sell machines for the european market, they assume that european buy pre-ground coffee (??????)
and therefore the OPV was kept as closed as possible to compensate for the ground variables
crazy?? yes

Us as vendor of equipment have to specify setting to the builders which apparently from importer to importer are somehow different

stefano65 wrote:I cannot speak for ECM
but last time this argument was brought to the attention of a well known Italian manufacturer
what I was told is that when sell machines for the european market, they assume that european buy pre-ground coffee (??????)
and therefore the OPV was kept as closed as possible to compensate for the ground variables
crazy?? yes

Very interesting! My ECM Giotto is set pretty high - I get more than 11 bar when I pressure test (with no flow from a gauged PF.) I want to dial it back but the dang thing is really stuck and can't get the adjuster to turn. It's an older ECM Giotto and I'm not sure what will work as a replacement part.

send me a picture if you like I can see if we can retrofit upgrade etc etc

For all E-61 owners, the Vibiemme Domobar Double manual I wrote has a illustrated and very detailed explanation of how an E-61 group works. You can download it from Stefano's EspressoCare.com website HERE.

Additionally, on my website I have a "How-To" documenting a complete E-61 group overhaul, with plenty of photos and step-by-step instructions. And to keep things running smoothly, a video on the Simple Lube of an E-61 which is particularly useful after a descaling.

stefano65 wrote:send me a picture if you like I can see if we can retrofit upgrade etc etc

Thanks, Stefano! I just sent a PM.

For any others interested, the expansion valve on my ~2002 ECM Giotto looks like this:
Is OPV on Giotto Classic and Premium the same?

Here is an alternative using a VBM and a 1/8 cup

I'm just following up to give a big thanks to Stefano, who found me a replacement valve that fit my 10 year old Giotto very nicely without adapters and is really easy to adjust:

Randy G. wrote:For all E-61 owners, the Vibiemme Domobar Double manual I wrote has a illustrated and very detailed explanation of how an E-61 group works. You can download it from Stefano's EspressoCare.com website HERE.

Randy,

You did an extraordinary job on that manual. Hopefully the rest of the world takes note and follows your lead.

-Ed

decaf_Ed wrote:Randy,
You did an extraordinary job on that manual. Hopefully the rest of the world takes note and follows your lead.
-Ed

Thanks, Ed! .. Hopefully, a part of the rest of the world hires me to write some manuals!

The new VBM DD is one of my best works. The DS manual, while very good, started out in color and the client switched to B+W later on, and then it ended up not being printed and could have remained in color. Problem was that I shot all the photos with color in mind and I would have lit them differently for B+W so the images are not what they could have been. The DD manual is another story. The photo I took to represent grinding too coarse still makes me laugh every time I see it. Coffee sprayed EVERYWHERE! Came within an inch or two of the camera.