existing hand-valves CV existing hand-valves CV gelsi (Chemical) (OP) 10 Mar 17 08:21 Hi, when need modifications of existing systems, we must often estimate the CV of hand-valves (example 1/2" gate valve on nitrogen blancketing line). Anyone can help me, i tried to find a table... Tx RE: existing hand-valves CV Latexman (Chemical) 10 Mar 17 13:16 Unless I have vendor data, I use the velocity head / K factor (not Kv) method for a wide open gate valve. I normally use K = 0.1 for a gate valve. K factor method You can use this and the appropriate equation and calculate a Cv. K to Cv Good luck, Latexman To a ChE, the glass is always full - 1/2 air and 1/2 water.