Siemens 371-03183 VALVE ASSY 2W NC 1/2", 4CV, EQ PCT BRASS TRIM FXF, PROP ELECTRONIC ACT NSRSiemens 371 03183 Valve assy 2W NC 1 2", 4Cv, Eq Pct Brass Trim FxF, Prop Electronic Act NSR Flowrite 599 Series Valve Assembly features a proportional control (0 to 10 Vdc or 4 to 20 mA), non spring return, 24 Vac electronic actuator. The 2 way, normally closed, 1 2 inch, 4 Cv valve assembly is ANSI Class 250 and has an equal percentage characteristic, brass trim, and female x female end connections. Additional Information Valve TypeTwo way Valve