A self-acting differential pressure controller with flow limitation, for return mounting, primarily for use in district heating systems. The controller closes on rising differential pressure or when set max. flow is exceeded.

Controller consist of:
- control valve (flange connection) type VFQ 2 / VFQ 21 with adjustable restrictor - for technical parameters look at part "Combine with..." below,
- pressure actuator type AFPB-F with control diaphragm and an internal spring for fixed differential pressure - see below.


Technical data

Code No.tmax
FunctionSetting typeMin. Dp setting
Max. Dp setting
Max. operation pressure


003G1026 150Diff. press. and flow limiterFixed0.20.225
003G1027 150Diff. press. and flow limiterFixed0.50.525