Series 642 DESIGN AND FUNCTION
742280ED Edition 2017-11-24 11/
3 Design and Function
3.1 Design
1 Valve gate 7 Gate seal
2 Ball guidance 8 Actuator shaft
3 Leaf spring 9 Counter plate
4 Ball pairs 10 Bonnet seal
5 Detents 11 Rotary feed through seals
6 Crank bolt
3.2 Function
The valve gate (1) acts as a throttling element and varies the conductance of the valve opening.
Actuation is performed with a stepper motor and controller. The stepper motor/controller version
ensures accurate pressure control due to exact gate positioning. For leak tight closing the VATLOCK
principle is applied. For details refer to VAT catalog.
14 3 9 2 5 7 6 8 11 10