OTV Technical Bulletin
Torques greater than the maximum specified are unnecessary and can damage the valve and in extreme over-torque cases might create unsafe conditions.
High over-torques can split the knob into 2 or 3 pieces. A cracked or split knob does not affect valve sealing; however, it indicates excessive torque applied to the knob. Replace a cracked or split knob immediately.
Please see the attached PDF file for further support.
Posted by Luxfer