Siemens 171K-10300 2W 1/2", 0.4CV BALL VALVE ASSY, CHRM-PLAT BRASS BALL & BRASS STEM, 2-10V, NO SRSiemens 171K 10300 This 599 Series 2 way ball valve with a 2 10 Vdc control, normally open, fail safe actuator assembly, providing 200 psi close off, is used to control hot or chilled water and up to 50% Glycol solution in convectors, fan coil units, unit conditioners, radiation and reheat coils. This 1 2 inch valve is 0. 4 Cv, equal percentage flow characteristic, with chrome plated brass ball and brass stem, and an operating handle that can manually