Hi, @robiienei
Welcome to the forum.
Please read the post at the start of any forum , entitled "How to use this Forum".
This will help with advice on how to present your code and problems.
Can you please post link to specs/data of the valve assembly?
Do you know if the valves are the type that responds to PWM proportional control?
What frequency does the valve data sheet say what the PWM frequency should be?
Can you please post a circuit diagram, an image of a drawing will be fine.
Please include all power supplies, component names and pin lables.
Thanks.. Tom..