Burkert Type 2000 Manuel D'utilisation page 15

6.2.4. incoming flow over seat
The valve is closed by spring force (control function A, CFA) with the
medium flow.
As the medium pressure is over the pendulum disk, it supports the
closing process of the valve and also contributes to the sealing of the
valve seat.
The valve is opened by the control pressure.
Warning!
risk of injury from water hammer.
A water hammer could crack the lines and device.
Due to the risk of water hammer, valves with a flow direction
above the seat must not be used for liquid media.
• Consider the type of flow direction and the type of medium for
operation of the device.
To ensure complete opening, the minimum control pressure
must be used!
14
english
Type 2000/2002
Structure and Function
Fig. 3: Incoming flow over seat (closing with medium)