Siemens 599-10304S 2W 1/2", 2.5 CV BALL VALVE, STAINLESS STEEL BALL & STEM, 200 PSI CLOSE-OFF, NPTSiemens 599 10304S 2W 1 2", 2. 5 Cv ball valve, stainless steel ball stem, 200 psi close off, NPT This 599 Series 2 way ball valve 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 2. 5 Cv, equal percentage flow characteristic, with stainless steel ball and stem, and an operating handle that can manually operate the valve in the