@jhope: you have started four topics on the forum, each prefixed "URGENT".
Might I suggest a course in time-management?
How about reading the posting guidelines?
It doesn't matter how many weak excuses you post, if you don't provide details, no-one can help you.
"the solenoid valve" tells us nothing apart from you have a valve controlled by a solenoid.
Not posting a schematic helps no-one.
You're using an NPN transistor? Whoop-de-do.
I'm coming around to the feeling that commonsense is the new superpower.
Remember: "Anchored in excellence"