I am unable to get to the valve link but the relay board basically has 2 single pole (k1 and k2) double throw contacts. I am going to make an assumption here since I have not seen the valve wiring. The three wires are likely.
Clockwise, or maybe open
Counter Clockwise, or maybe close
It is very likely I got the descriptions wrong but it should be helpful anyway.
In my example I would connect #3 to your power supply negative, common, or neutral.
I would then connect your power supply hot, or positive to the center screw terminal on your relay board.
Connect your valve close #2 to the normally closed screw terminal on the relay board shown on the right of the center screw.
Connect your valve open #1 to the normally opened screw terminal on the relay board shown on the left of the center screw.
Therefore when the relay is energized “on” you will have power flow from the center terminal to the left terminal and the valve will open, when the relay is de-energized “off” you will have power flow from the center terminal to the right terminal and the valve will close.
Your schematic looks pretty good.
One word of caution would be your transformer is showing a 240 vac input. I am not sure of your location but the valve specifications in the link you provided is 60 Hz. Not sure the impact if you are on a 50Hz system.