(Doug's images links were broken. So I repost them here.) bidoowee
The Aurora Europa, AKA Termozona is one of the few true heat exchange single group espresso machines from the vintage era. This particular machine is from the 1970's. I say single group since many of the different machine manufacturers used a dipper feed for the single groups and HX for the multiple group machines, but the Aurora is a true single group HX with a large boiler and small footprint. I have been told that Brungnetti made all or at least most of their components "in house" and this shows in the Europa, since most of the components are unique to the Aurora machines, with not a lot of interchange from or to other machine makes.
The boiler is large and I have modified the layout a bit by removing the autofill system (I think it is not needed in a home application and adds to the complexity of long term use/maintenance). The blind cap on the end plate closes the autofill fitting and instead of the probe on the top of the boiler I added a vac valve to make warmup a simple and rapid event. Below you can follow th HX water route quite clearly...fresh water from the water line enters the HX through the large fitting on the left of the end plate and exits through the other large fitting on the right. A pipe goes directly to the top of the group and fills a space in the neck behind the group. The water in this space brews the shot. The HX tube is about 1" diameter copper pipe.
The machine is 110volt as original.
Full size 30 amp Sirai pstat mounts under the boiler and is pressure fed by a pipe from the bottom of the water level sight glass housing.
This view shows that all of the piping comes from the boiler plate side. The boiler is suspended by the pipes and the group to boiler flange.
Special attention has been paid to the top lever/fulcrum mechanism with the bearings tightly encased in a cast frame. The bearings roll on replaceable shoes and are held in alignment with adjustable side plates. The piston is removed by threading out the slot head screws below the lever bearing housings.
Very simple front work area with manometer indicating a .7 to .9 bar sweet spot for pstat adjustment. The wands can be made to swivel but are generally fixed in postition. The drip tray is held in place by a spring clip mechanism.
Under the tray is the drain sump and the water inlet valve. The rear port of the valve feeds the HX tube and is always on and the front port of the valve corresponds to the manual boiler fill and is controlled by the side exit handle. The overpressure valve that empties into the sump is fed by a side branch from the HX line. This would function as a pressure limiter on the water line but it is better to use a stand alone line valve for this. The HX pressure regulator shown here is more or less a safety feature and as I have it set up does not function well to regulate HX line pressure.
The heating element and HX loop inside the boiler are built almost right into one another.
And the HX tube is directly above the heating element.
Another view of the heart if not soul of this system.
The spring on the Aurora is possibly the strongest I have encountered, which means that it was VERY difficult to install. Compression of the spring was 100% at the point I was able to insert the upper rod pin. This view is of a new spring and clean piston with new seals.
The face of the piston has large pressurizing holes to keep the seal tight against the cylinder walls. The piston uses the same V and W seal system as found in the classic Faema groups.
These are some of the salient features of the Aurora Europa save the case. In general the machine is simple and overall not bad to work on....there are some order counts issues in assembling the frame components at the sight glass and electrical switch panels. The sight glass parts come out as a unit, but the sheet metal must be removed first...not as convenient as some. The HX is a very nice system on these machines since one can both heat and cool the group at will and pulling shots does not deplete the boiler....one can pull a shot and steam at the same time of course, and this is part of the point of this type of system.
The Aurora Europa, AKA Termozona is one of the few true heat exchange single group espresso machines from the vintage era. This particular machine is from the 1970's. I say single group since many of the different machine manufacturers used a dipper feed for the single groups and HX for the multiple group machines, but the Aurora is a true single group HX with a large boiler and small footprint. I have been told that Brungnetti made all or at least most of their components "in house" and this shows in the Europa, since most of the components are unique to the Aurora machines, with not a lot of interchange from or to other machine makes.
The machine is 110volt as original.
Full size 30 amp Sirai pstat mounts under the boiler and is pressure fed by a pipe from the bottom of the water level sight glass housing.
This view shows that all of the piping comes from the boiler plate side. The boiler is suspended by the pipes and the group to boiler flange.
Special attention has been paid to the top lever/fulcrum mechanism with the bearings tightly encased in a cast frame. The bearings roll on replaceable shoes and are held in alignment with adjustable side plates. The piston is removed by threading out the slot head screws below the lever bearing housings.
Very simple front work area with manometer indicating a .7 to .9 bar sweet spot for pstat adjustment. The wands can be made to swivel but are generally fixed in postition. The drip tray is held in place by a spring clip mechanism.
Under the tray is the drain sump and the water inlet valve. The rear port of the valve feeds the HX tube and is always on and the front port of the valve corresponds to the manual boiler fill and is controlled by the side exit handle. The overpressure valve that empties into the sump is fed by a side branch from the HX line. This would function as a pressure limiter on the water line but it is better to use a stand alone line valve for this. The HX pressure regulator shown here is more or less a safety feature and as I have it set up does not function well to regulate HX line pressure.
The heating element and HX loop inside the boiler are built almost right into one another.
And the HX tube is directly above the heating element.
Another view of the heart if not soul of this system.
The spring on the Aurora is possibly the strongest I have encountered, which means that it was VERY difficult to install. Compression of the spring was 100% at the point I was able to insert the upper rod pin. This view is of a new spring and clean piston with new seals.
The face of the piston has large pressurizing holes to keep the seal tight against the cylinder walls. The piston uses the same V and W seal system as found in the classic Faema groups.
These are some of the salient features of the Aurora Europa save the case. In general the machine is simple and overall not bad to work on....there are some order counts issues in assembling the frame components at the sight glass and electrical switch panels. The sight glass parts come out as a unit, but the sheet metal must be removed first...not as convenient as some. The HX is a very nice system on these machines since one can both heat and cool the group at will and pulling shots does not deplete the boiler....one can pull a shot and steam at the same time of course, and this is part of the point of this type of system.
Hey Thomas, I just realized this is your blog(I'm Sam from HB forum)! Keep it up! And a big THANK YOU for archiving this post of OE. I had read it at the time but the pictures were missing, which was a big disappointment! Thanks for keeping & sharing the pics!
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