Saeco PRIMEA LINE 2007 Technical & Service Manual page 51

6.5 SBS valve
Beverage dispensing
The SBS brew unit valve (see fig. 2) can be used to vary (increasing or decreasing depending
on the position of the knob) the amount of water passing through the brew unit.
This adjusts coffee brewing time (extraction time) and consequently the intensity of taste,
keeping the cream quality constant.
Function
With the SBS valve in the open position, coffee is accumulated in the membrane valve due to a
low back-pressure of the SBS valve. Consequently the membrane valve needle remains in the
maximum open position, due to resistance of the spring. Coffee comes out quickly (see Fig. 3).
With the SBS valve in the closed position, coffee is accumulated on the membrane of the valve
with a consequent increase in pressure in the valve. The spring yields to the back-pressure and
the needle then reduces the coffee passage (see Fig. 4).
Fig.2
Fig.1
Fig.3
Fig.4
PRIMEA 2007 Chapter 06
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REV. 00 - Mar. 07