The solenoid valve might be one of the most important components for a modern espresso machine. This is the case with domestic and commercial coffee machines.
In the basis there are 2 types of solenoid valves, the 2 way valve and the 3 way solenoid valve. The 2 way solenoid valve is used for applications such as water dosing, steam dosing and for the water inlet valve. The 3 way valve is mainly used on the brewing valves as a exhaust valve.
Between the 2 and 3 way solenoid valve there are also differences like the diameter of the orifice, the in and outlet connection and the voltage. The solenoid valves used on espresso machines are mainly made by 4 manufacturers: