Butterfly Valves - Flow Coefficients Cv

Typical flow coefficients (Cv) for butterfly valves at different opening positions. This tool provides data for butterfly valves ranging from 2 to 20 inches with flow coefficients at various disc angles (90°, 70°, 50°, 30°) and pressure ratings (ANSI 150, ANSI 300). Manufacturers data should always be checked before actual use. Conversion: 1 ft/s = 0.3048 m/s

Valve Size (inches)	Cv at 90° (wide open)	Cv at 70°	Cv at 50°	Cv at 30°	ANSI 150 (ft/sec)	ANSI 300 (ft/sec)
2	50	85	65	35	15	90	90
2 1/2	65	160	120	65	29	80	90
3	80	260	195	104	47	80	80
4	100	475	356	190	86	80	80
5	125	770	577	308	139	80	80
6	150	1125	844	450	203	75	80
8	200	2110	1583	844	380	70	75
10	250	3350	2513	1340	603	60	70
12	300	4800	3600	1920	864	50	60
14	350	6900	5175	2760	1224	50
16	400	9000	6750	3600	1620	50
18	450	11800	8850	4720	2124	50
20	500	14300	10725	5720	2574	50