multiple turn hand-operated check valve

[chem0107]

I had 12 inch hand-operated valve. It has hex shaft operator. I am looking for tool to turn this valve . Do you know any tool out there that has anti clock control or a safety feature that can disengage the motor as the valve comes to its stall? there is a pneumatic nutrunner with automatic shut-off features but i can's use it b/c i don't know the torque value for this typical valve.

I am appreciated alot for your help.

Ba