TECHNICAL MANUAL
Speedster page 51
Exchanging jets for different infusion
The Speedster coffee water system contains 2 restrictors (or jets): one inside the group
head (see figure 15), the other in the tube that leads from the heat exchanger to the
coffee boiler (see figure 32). Standard, a jet with 0.6 mm diameter is mounted in the
group head and a 1.5 mm jet is mounted in the tube, the only function of the latter is to
protect the threads in the tubes’ connector.
Figure 32. Shows location of restrictor in tube from heat exchanger to coffee boiler.
When the two jets are swapped, the infusion changes dramatically. Once the group valve
is activated (brewing lever in middle position), the pressure inside the coffee boiler (up to
12 Bar) will soak the coffee grounds rapidly while pressure is also released into the pre-
infusion cylinder. Since the 0.6 mm jet restricts the flow towards the coffee boiler, the
pressure on the grounds reduces to practically zero before increasing only gradually to
line pressure (or pump pressure when pump is activated).
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