SUNFORD VALVES

CV Flow Coefficients

API 6D

Bore (Inches)	Classes
Bore (Inches)	150	300	600	900	1500	2500
2	420	420	400	330	330	250
21 / 2	690	690	610	520	510	320
3 x 2	200	200	200	190	180	200
3	1200	1050	1000	910	820	500
4 x 3	600	600	600	590	550	560
4	2200	2100	1850	1800	1700	1100
6 x 4	800	800	790	790	780	745
6	5150	5100	4600	4380	3800	2500
8 x 6	2150	2150	2150	2150	2150	2150
8	9500	9400	9000	8500	7400	5300
10 x 8	4300	4300	4450	4450	4100	4100
10	15000	15000	14700	14500	11500	8300
12 x 10	7550	7550	7550	8000	9000	7550
14 x 10	6000	6000	6000	6100	6100	-
12	23000	23000	22500	21100	18000	13000
14 x 12	14000	14000	14000	12800	13000	-
16 x 12	9100	9100	9100	8900	8900	-
14	28000	28000	28000	25000	21000	-
16 x 14	15000	15000	15000	14200	14100	-
16	37200	37200	37200	34500	27500	-
18	21000	21000	21000	19200	19000	-

Data for Calculation of Flow
The coefficient of flow Cv expresses the rate of flow in gallons per minute at 60°F water with a pressure drop of 1 psig across the valve.The Cv coefficients for the various types and sizes shown in the tables, have been determined from actual flow tests.

Note: Kv is the metric equivalent of Cv.
KV = CV x 0.85

For Liquids:

Where QL = Flow in U.S. gallons per minute.
Δ P = (P1–P2) Pressure drop in psi.
GL = Specific gravity of liquid (water = 1 at 60°F).

For Gases:

Where Qg = Volumetric flow of gas (SCFH).
Gg = Specific gravity of gas at standard conditions.

(air at atmosphere and 60°F = 1)
T = Absolute temperature of gas
(°F + 460).

Note: For gas, max. ΔP = 1⁄2 P1, and min.
P2 = 1⁄2 P1, and P1, P2 are absolute pressures (psia)