The present invention relates to a Ball Valvesformed of a housing with inlet and outlet openings for a medium and a ball having a bore and floatingly supported in two rings in the housing.Ball Valves The ball in one of its rotary positions connects the inlet and the outlet and in another of its rotary positions interrupts the inlet and outlet. The ball valve includes an actuator rotatable with the ball and in rotary engagement therewith.

Ball valves, in particular with the ball not in journalled bearings, usually called "floating ball" have, in general, better sealing properties but poorer torque behaviour than so-called journalled ball valves.

The better sealing properties with a floating ball result from the higher surface pressures on the sealing surfaces, while the high torques are attributed to the larger friction radius (ratio of the ball diameter of the journal diameter).

The criterion with actuation of valves is the so-called initial breakaway torque. This proportionately high torque appears with the opening of the valve. It is, inter alia, dependent on the standing period of the valve under one-sided pressure. The magnitude of this breakaway or adhesion torque is, according to the construction principle and the condition of the sliding surfaces, 2 to 5 times as high as the sliding torque of the valve, which is required for the rotation of the ball after the breakaway until the equalization of pressure that is, until the release of the discharge.BALL VALVES The torque, which is necessary after the pressure equalization until full opening of the valve (idle or free torque) amounts only to 5 to 15% of the adhesion torque.

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