Danfoss AVPB (003H6399) — self-acting differential pressure control and flow limiter, PN 16, DN 15, for district heating and central heating systems. The AVPB closes on rising differential pressure or when the set maximum flow is exceeded, holding a stable differential pressure across the controlled circuit so that connected control valves keep their authority. The controller combines a control valve with an adjustable flow restrictor and an actuator with one control diaphragm and handle for differential-pressure setting. Differential-pressure setting 0.2 – 1.0 bar adjustable; flow rate 0.06 – 1.4 m³/h. Maximum differential pressure 12 bar, maximum water temperature 140 °C, cavitation factor z ≥ 0.6. Valve body red bronze Rg 5 (CuSn5ZnPb, DIN 1705 W.no. 2.1096.01), control diaphragm EPDM, valve insert/spindle CrNi steel 1.4404. Connection external thread G ¾ A (ISO 228/1) via tailpieces (ordered separately). Media: water for district/central heating; glycolic water up to 30% resistant to -30 °C. OEM P/N 003H6399. Technical data quoted verbatim from the Danfoss AVPB/AVPB-F PN 16 data sheet and store.danfoss.com (code 003H6399). 2.1096.01); valve insert/spindle CrNi steel 1.4404; control diaphragm EPDM; Pressure rating: PN 16 (max. differential pressure 12 bar); Temperature range: up to 140 °C (heating water); glycolic water resistant to -30 °C; HS code: 8481.80. Used in commercial refrigeration, provision-room cooling and reefer plant rooms across HFC, HFO and CO2 (R744) refrigerants.