ESD protection on a solenoid driver circuit
I am not sure, what the question is, but i know what did you forget. You have also to protect the gate driver. This is because between the gate and the drain (and source) there is some capacitance which in case of ESD discharge will just conduct, so a voltage surge is possible on the gate.

upd. in case of such surge one of the implications may be opening the valve. not very nice.