You will only get water hammer when sudden changes are made to flow, in the case you describe two possibilities arise.
I would place a shut off valve just upstreem (in the pipe) of the turbine for maintaining your unit, and a smaller air purge valve upstream of that. When closing this do so slowly and no water hammer will occure.
When first filling the line do so with the turbine end valve closed and air purge open then slowly allow the water to enter, how you achieve this is up to you, it could be as simple a a piece of board across the entrance such that only a small opening is made.
allan down under