Siemens 171K-10311 2W 3/4", 25CV BALL VALVE ASSY, CHROME-PLAT BRASS BALL, BRASS STEM, 2-10 V NO SRSiemens 171K 10311 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 3 4 inch valve is 25 Cv, full port valve without flow characterizer insert, with chrome plated brass ball and brass stem, and an operating handle that