Danfoss AVPB-F (003H6476) — self-acting differential pressure control and flow limiter, PN 25, DN 50, for district heating and cooling systems. The AVPB-F closes on rising differential pressure or when the set maximum flow is exceeded, holding a stable differential pressure across the controlled circuit so connected control valves keep their authority. It combines a control valve, an adjustable flow restrictor and an actuator with one control diaphragm set to a fixed, factory-preset differential pressure (sealed, non-adjustable). Differential-pressure setting fixed 0.5 bar (factory-preset, non-adjustable); flow rate 0.8–15 m³/h; Kvs 25 m³/h. Maximum differential-pressure range 16 bar, media temperature 2–150 °C, cavitation factor z ≥ 0.6, seat leakage 0.05 % Kvs (IEC 60534). Valve body Ductile iron EN-GJS-400-18-LT (GGG 40.3); valve cone dezincing-free brass CuZn36Pb2As; seat stainless steel 1.4571; control diaphragm and DP sealing EPDM. Connection Flange (PN 25), tailpiece thread G 2½ A. Media: district heating/cooling circulation water. OEM P/N 003H6476. Technical data quoted verbatim from store.danfoss.com (code 003H6476) and the Danfoss AVPB/AVPB-F (PN 16, 25) operating guide. differential-pressure range 16 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.