wT 2858/02
Page 18
9
Operating Principle
With its "elastic sealing system" the ball valve guarantees full tightness at both high and
lowest pressures. The necessary contact forces between the ball-shaped shut-off section
and the sealing elements are generated by the pressure differential created in the shut-
off valve. With regard to this sealing principle, the "FLOATING BALL", it is important that
the shut-off section between the two sealing rings is movable. These rings carry out a
double function: They guide the ball and act as force transducers.
DISTRIBUTION OF FORCES
This principle is used in combination with ball valves of smaller nominal sizes. As the
nominal sizes increase, so do the forces which have to be absorbed by the sealing rings.
In order to achieve a long service life and to keep the torques for the pivoting of the ball
as low as possible, this three-component design is not suitable for all nominal sizes.
10
Mode of Operation
The two pre-stressed elastic sealing elements made of stainless steel with KFC sealing
rings, a K-Flon sleeve at the upstream and downstream side of the ball valve and the ball
create the sealing system.
The pressure of the medium presses the ball onto the downstream sealing element. At
the same time, the upstream element is also pressed against the ball. The Ballostar® ball
valve is maintenance-free and can be pressurized in both flow directions.
