A few weeks I decided, after months of thinking about it that I would
adjust the brew pressure from its approx 13 bar to a more respectable
level. Although Id managed to get reasonably predictable, and usually
quite good, results at this level, reading around here and elsewhere
and observing the improvement KJM had achieved in adjusting his Silvia
convinced me to give it a go. Even more so when I had the opportunity
to borrow a manometer from KJM.
Now for most machines there are at least at few hints on the web about
adjustment specifics. For the Mondiale, not a sausage. Talking to
various people had led to responses from "only an expert can do it" to
"the Mondiale doesnt have an adjustable OPV" to "youll never get it
back together again", so I thought Id write a brief report to put the
mythology to rest and show that (as one would expect) it isnt that
difficult after all.
First of all I made some measurements. I removed the single spout from
of our portafilters, and screwed on the manometer (with some plumbers
tape). This showed readings about the same as on the Mondiales gauge
(the manometer is in kg/cm2 so there is some difference). I made
adjustments with the machine cold as much as possible.
Below is a composite picture with four panels. The first shows just
the top with two screws removed so that the cup warmer can be tilted
back to give some internal access. At the right is a component with an
orange top -- this is the pressurestat, which can be easily adjusted
with no further dissection of the machine necessary. I adjusted so
that it settles back to 1.1 bar (on the Mondiales gauge).
The first picture also shows to small red arrows. These are screws
that need to be removed to commence removing the casing of the
Mondiale, which is its distinguishing feature and also what makes it a
bit more difficult to get inside than other Isomac HX machines.
There are also two screws at the front to be removed. The second
picture has more small red arrows indicating these. To get at them, I
removed the drip tray, unscrewed the front legs, and removed the
ledges on which it rests (all shown in the picture). I also removed
four (I think) screws behind the machine (not shown). At this point,
the sides spring apart and the outer casing can be removed.
The third picture shows what things look like at this point. Shown
tilting back is the platform that supports the water container (which
I had of course removed before starting disassembly). On the right is
a partial view of the removed casing, used as a support. And on the
left is the important bit.
The fourth picture is a closeup on the OPV itself, shown with another
red arrow (by then I had figured out how to make the arrows somewhat
bigger
). To adjust it, I removed the tube, put a couple of white
dots to measure how many turns, then rotated the inner barrel to
adjust. Anticlockwise lowers the setting. To get it moving, I had to
use a small pliers (with jaws padded) but it was then pretty smooth.
Getting water into the machine at this point needs a little
thought. One way is run the tubes into a separate container, and put a
weight on the platform to keep the water level sensor depressed. I
didnt do that, I carefully positioned the platform in a stable
position and used the machines water container. After a few
iterations I finished with a reading of 9 bar (about one full turn).
Getting the thing back together is the most difficult part of the
exercise. The casing springs out quite a lot, and needs a careful
balance of tension to get everything lined up properly. With two of
us, it wasnt too difficult, but a touch tricky. No new four letter
words needed
.
Internally, the machine has a very similar layout of OPV etc to both
the Isomac Tea and Zaffiro.
Removed inactive link.....
Mal.
This wiki (which has an enormous amount of useful information,
including an article on different types of OPV) is now member-only
access; Ive emailed Dave to find out how to subscribe.
As for results -- it was well worth the effort. Its much easier to
make shots at finer grind, which gives crema with a finer structure
and greater discrimination along the flavour spectrum (for want of a
better way to put it).

adjust the brew pressure from its approx 13 bar to a more respectable
level. Although Id managed to get reasonably predictable, and usually
quite good, results at this level, reading around here and elsewhere
and observing the improvement KJM had achieved in adjusting his Silvia
convinced me to give it a go. Even more so when I had the opportunity
to borrow a manometer from KJM.
Now for most machines there are at least at few hints on the web about
adjustment specifics. For the Mondiale, not a sausage. Talking to
various people had led to responses from "only an expert can do it" to
"the Mondiale doesnt have an adjustable OPV" to "youll never get it
back together again", so I thought Id write a brief report to put the
mythology to rest and show that (as one would expect) it isnt that
difficult after all.
First of all I made some measurements. I removed the single spout from
of our portafilters, and screwed on the manometer (with some plumbers
tape). This showed readings about the same as on the Mondiales gauge
(the manometer is in kg/cm2 so there is some difference). I made
adjustments with the machine cold as much as possible.
Below is a composite picture with four panels. The first shows just
the top with two screws removed so that the cup warmer can be tilted
back to give some internal access. At the right is a component with an
orange top -- this is the pressurestat, which can be easily adjusted
with no further dissection of the machine necessary. I adjusted so
that it settles back to 1.1 bar (on the Mondiales gauge).
The first picture also shows to small red arrows. These are screws
that need to be removed to commence removing the casing of the
Mondiale, which is its distinguishing feature and also what makes it a
bit more difficult to get inside than other Isomac HX machines.
There are also two screws at the front to be removed. The second
picture has more small red arrows indicating these. To get at them, I
removed the drip tray, unscrewed the front legs, and removed the
ledges on which it rests (all shown in the picture). I also removed
four (I think) screws behind the machine (not shown). At this point,
the sides spring apart and the outer casing can be removed.
The third picture shows what things look like at this point. Shown
tilting back is the platform that supports the water container (which
I had of course removed before starting disassembly). On the right is
a partial view of the removed casing, used as a support. And on the
left is the important bit.
The fourth picture is a closeup on the OPV itself, shown with another
red arrow (by then I had figured out how to make the arrows somewhat
bigger
). To adjust it, I removed the tube, put a couple of whitedots to measure how many turns, then rotated the inner barrel to
adjust. Anticlockwise lowers the setting. To get it moving, I had to
use a small pliers (with jaws padded) but it was then pretty smooth.
Getting water into the machine at this point needs a little
thought. One way is run the tubes into a separate container, and put a
weight on the platform to keep the water level sensor depressed. I
didnt do that, I carefully positioned the platform in a stable
position and used the machines water container. After a few
iterations I finished with a reading of 9 bar (about one full turn).
Getting the thing back together is the most difficult part of the
exercise. The casing springs out quite a lot, and needs a careful
balance of tension to get everything lined up properly. With two of
us, it wasnt too difficult, but a touch tricky. No new four letter
words needed
.Internally, the machine has a very similar layout of OPV etc to both
the Isomac Tea and Zaffiro.
Removed inactive link.....
Mal.
This wiki (which has an enormous amount of useful information,
including an article on different types of OPV) is now member-only
access; Ive emailed Dave to find out how to subscribe.
As for results -- it was well worth the effort. Its much easier to
make shots at finer grind, which gives crema with a finer structure
and greater discrimination along the flavour spectrum (for want of a
better way to put it).


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