Burkert Type 2731 - Manual (Page 9)

5.2.1 Device versions
actuator sizes
The piston-controlled diaphragm control valve is available for the
following actuator sizes:
ø 80 mm, ø 100 mm, ø 125 mm.
pilot pressure
Designs with lower pilot pressure (reduced spring force) are available
on request.
Contact your Bürkert sales office or our Sales Center, e-mail:
[email protected]
5.3 structure and function
The operation of the diaphragm control valve Type 2730 / 2731
/ 2731K is possible only in combination with an control unit.
Possible control units are:
Positioner Type 8630, 8635, 8692, 8694, 8792
Process controller Type 8693, 8793
5.3.1 structure
The piston-controlled diaphragm control valve consists of a pneumati-
cally operated piston actuator and a 2/2-way valve body.
Actuator cover
Actuator body
Diaphragm socket
Line connection
Diaphragm body
Lower pilot air port
Upper pilot air port
Diaphragm
Fig. 3: Structure and description
5.3.2 function / control functions (cf)
Spring force (CFA) or pneumatic pilot pressure (CFB) generates the
closing force on the diaphragm pressure piece. The force is transferred
via a spindle which is connected to the actuator piston.
control function a (cfa)
Normally closed by spring action
control function B (cfB)
Normally open by spring action
9
Productdescription
english
Type 2730 / 2731 / 2731K