AVQT is a self-acting flow and temperature controller primarily for use in district heating systems. The controller closes on rising temperature or when set max. flow is reached. AVQMT is a self-acting flow and temperature controller with integrated control valve primarily for use in district heating systems. The controller closes on rising temperature or when set max. flow is reached. AVQT controller can be combined with AVT or STM thermostatic actuators. AVQMT controller can be combined with Danfoss electrical actuators AMV(E) (and controlled by ECL electronic controllers) and with AVT or STM thermostatic actuators. The controllers AVQT and AVQMT have a control valve with adjustable flow restrictor, connection neck for thermostat, connection neck for electrical actuator (AVQMT only), and a pressure actuator with one control diaphragm.