You can use a torque wrench but if you feel like you are crushing the gasket stop tightening even if you haven't hit the torque setting. You don't want to crush the gasket. I normally put then on with a normal wrench and just do it by feel.
Firefly: Mal: You don't know me, son, so let me put this to you plainly: If I ever kill you, you'll be awake. You'll be facing me. And you'll be armed.