Danfoss AVD-S (003H6666) — self-acting pressure reduction controller, PN 25, DN 15, for steam and circulation-water systems. The AVD-S is a self-acting pressure reduction controller for steam and circulation-water systems. It is normally open and closes on rising downstream pressure, holding the reduced (outlet) pressure constant at the setpoint. It has a control valve, an actuator with one control diaphragm and a spring for the pressure setting; the steam variant uses a hardened stainless-steel valve cone. Reduced-pressure setting range 1–5 bar adjustable; Kvs 1.6 m³/h. Maximum differential-pressure range 10 bar; media temperature 2–200 °C; cavitation factor z ≥ 0.6; seat leakage 0.05 % Kvs (IEC 60534). Valve body Red bronze CuSn5ZnPb (Rg5); valve cone Stainless steel, mat. 1.4122; seat Stainless steel, mat. 1.4571; control diaphragm EPDM. Connection External thread G 3/4 A (ISO 228/1), via tailpieces. Mounting version Flow. Permissible media: Steam (Circulation water). OEM P/N 003H6666. Technical data quoted verbatim from store.danfoss.com (code 003H6666) and the Danfoss AVD / AVD-S (PN 25) pressure reduction controller data sheet. 1.4122; valve seat Stainless steel, mat. 1.4571; control diaphragm EPDM; Pressure rating: PN 25 (max. differential-pressure range 10 bar); Temperature range: 2 to 200 °C (steam/circulation water); HS code: 8481.80. Used in commercial refrigeration, provision-room cooling and reefer plant rooms across HFC, HFO and CO2 (R744) refrigerants. No. No.