Danfoss SAVD (003H6977) — self-acting safety pressure-reduction controller, PN 25, DN 50, free mounting, for district heating and central-heating circuits. The SAVD is a self-acting safety pressure-reduction controller that requires no auxiliary energy: it reduces and limits the downstream pressure, closing on rising outlet pressure, using a control valve and a spring-loaded actuator diaphragm. As a safety controller (SAV pressure-reduction) it provides the self-acting overpressure protection required for district-heating substations, independent of any electric control. kVS 25 m³/h; adjustable pressure setting range 2 – 8 bar; maximum differential pressure 16 bar. Medium temperature 2–150 °C; leakage 0.05% of kVS (IEC 534); Valve body ductile iron EN-GJS-400-18-LT (GGG 40.3), valve seat stainless steel 1.4571, valve cone dezincing free brass CuZn36Pb2As, actuator diaphragm EPDM. Connection flange PN 25. OEM P/N 003H6977, EAN 5710104031262. Technical data quoted verbatim from store.danfoss.com (code 003H6977).