Technical Principles
1ª review – UK 06 – 2019
11
A11. Water pump
This element has the job of pumping water
from the cold water deposit to the hot
water boiler; the cold water pushes the hot
water towards the EVs for the instant
products or towards the
infusion element
for making espresso coffee
When an espresso coffee is elaborated, the water pressure needed is quite high to be able to
pass through the compressed ground coffee in the
infusion element
. This resistance the coffee
offers makes the water pressure in the boiler increase up to a pressure of 9 Kg/cm². At this
pressure the by-pass opens allowing a small amount of water to return; sufficient to prevent
the water pressure from going over the 9 Kg/cm².
The by-pass is a small hole covered with a ball that is held in place by a spring. This spring will
hold a pressure of 9 Kg/cm², but over this pressure it compresses and allows the water to
pass.
The pressure of 9 Kg/cm² is considered the ideal for elaborating espresso coffee.
When the instant beverages are elaborated, there is no resistance offered and so during there
elaboration the water pump works at lower pressures than when elaborating espresso coffees.
Technical characteristics
:
Voltage
230 Vdc
Power
48 w
Working pressure
9 Kg/cm²
Maximum pressure
12 Kg/cm²
The pump has an anti return valve that prevents the return of water from the boiler.
