Danfoss AVQT (003H6761) — self-acting flow and temperature controller, PN 25, DN 15, for district heating and cooling systems. The AVQT holds the flow constant and limits it to the set maximum and closes on rising temperature. It accepts an AVT thermostatic actuator, or an STM safety temperature monitor where over-temperature protection is required. It comprises a control valve with adjustable flow restrictor, a connection neck for the thermostatic actuator, and a pressure actuator with one control diaphragm. Flow range 0.07 - 2.4 m³/h; flow-restrictor differential pressure 0.2 bar; Kvs 4 m³/h. Maximum differential-pressure range 20 bar; media temperature 2–150 °C; cavitation factor z ≥ 0.6; seat leakage 0.02 % Kvs (IEC 60534). Temperature is set by the separately ordered AVT thermostatic actuator, setting ranges 10–40 / 20–70 / 40–90 / 60–110 °C and 10–45 / 35–70 / 60–100 / 85–125 °C (AVT actuator, ordered separately); the controller is delivered assembled with the impulse tube between valve and actuator, the actuator ordered separately. Combined with AMV(E), AVT or STM actuators the controller is type-tested to EN 14597. Valve body Red bronze CuSn5ZnPb (Rg5); valve cone Dezincing free brass CuZn36Pb2As; seat Stainless steel, mat. 1.4571; control diaphragm EPDM. Connection External thread G 3/4 A (ISO 228/1), via tailpieces. Mounting version Free. Permissible media: District heating/cooling circulation water (Glycolic water up to 30%), pH 7–10. OEM P/N 003H6761. Technical data quoted verbatim from store.danfoss.com (code 003H6761) and the Danfoss AVQT / AVQMT (PN 25) data sheet. 1.4571; control diaphragm EPDM; Pressure rating: PN 25 (max. differential-pressure range 20 bar); Temperature range: 2 to 150 °C (district heating/cooling water); HS code: 8481.80. Used in commercial refrigeration, provision-room cooling and reefer plant rooms across HFC, HFO and CO2 (R744) refrigerants. No.