Danfoss AB-PM DN 40 — combined automatic balancing valve and differential-pressure controller (standard version) for hydronic heating and cooling systems. The AB-PM integrates four functions in one flanged body: a differential-pressure controller that holds a constant Δp across the connected terminal or riser, an automatic flow limiter (presetting caps the maximum flow), a modulating control-valve seat driven by a Danfoss actuator on the Danfoss standard connection, and a manual shut-off. Because the valve keeps the differential pressure stable, connected control valves retain their full authority and the branch stays balanced across all load conditions without manual re-commissioning. Grey cast iron EN-GJL-250 (GG-25) body, PN 16, differential-pressure range 42 KPa to 4000 KPa, maximum controllable flow 5.0 m³/h at Δp=25 kPa, stroke 10 mm, media temperature -10 °C to 120 °C, mounted in the return pipe. Connection: Flange (EN 1092-2)G 2A. OEM P/N 003Z1435. Technical data quoted verbatim from store.danfoss.com (code 003Z1435). Used in commercial refrigeration, provision-room cooling and reefer plant rooms across HFC, HFO and CO2 (R744) refrigerants.