Choosing proper size of solenoid valve
Bad datasheet?
You should be aware that the datasheet linked is most likely not the correct one for the valve you will receive if you buy through that link. Various user comments and even the official description suggest this.
Wrong architecture?
This is not the right type of valve for your application:

Note: This is not a gravity-feed solenoid. This means that you will
need enough water pressure to fully open the valve. Check the
datasheet below for exact details. It operates at a minimum of around
3 PSI

Your application (coffee maker) is most-likely gravity-fed. That means you have a tank of water and you let it out into your machinery for use driven solely by its own weight. With this valve, you will not be able to fully drain the tank. As the level gets lower, the pressure on the valve will decrease to the point that the valve won't open.
If you are using this valve you will need a pump on the tank-side of the system.
Wrong forum?
The detail of mechanical actuation and pressure systems is probably better handled on one of the mechanical engineering or physical sciences forums.