The controller is a self-acting pressure relief controller primarily for use in district heating systems. The controller is normally closed and opens on rising pressure.The controller has a control valve, an actuator with one control diaphragm and a spring(s) for pressure setting.Further on two valve versions are available:∙ VFG 22 with metallic sealing cone∙ VFG 221 with soft sealing coneTogether with Danfoss intelligent electrical actuator AMEi 6 intelligent optimization functions are available:∙ iNET-intelligent network balancing