With a standard bolt and nut. Create 2 areas, red and green, red surface = green surface. Green surface is closer to the center than red surface. Red surface is between up surface of bolt and bot surface of nut. Green surface is between down surface of bolt and top surface of nut. We put the same pressure from fluid in green and red volumes. Like surfaces are equal the bolt can move up or down without need energy. The nut turn only and the bolt move up/down only. Like green surface is closer to the center, the torque on the nut is bigger with red surface. The outside pressure is lower than pressure in red/green volumes. Like this it seems the nut turn with a torque, where is the problem ?