Cv Flow Coefficient Table
Data for Calculation of Flow and / or Pressure Drop
Kv = Cv x 0.85
A Valve coefficient Cv is used to calculate pressure drop through a particular Valve for a given flow rate. The coefficient of flow Cv expresses the rate of flow in gallons per minute at 60o F water with a pressure drop of 1 psig across the valve. The Cv coefficients for the various types of size, shown in the tables, have been determined form calculations and actual flow tests.
Note: Kv is the metric equivalent of Cv
For Liquids:
Where QL=Flow in U.S. Gallons per minute.
ΔP = (P1 – P2) Pressure drop in psl.
GL = Specific gravity of liquid ( Water = 1 at 60o F )
For Gas:
Where Qg = Volumetric flow of gas (SCFH)
Gg= Specific gravity of gas standard conditions (air at atmosphere and 60o F = 1) T = Absolute temperature of gas ( o F + 460 )
For Steam:
Note : For saturated steam TS = 0
W W = Pounds per hour of steam
ΔP = (P1 – P2) Pressure drop in psl
TS = Degree of superhear ( o F )
Note ; For gas and steam, max. ΔP = 1/2 P1 and min. P2 = 1/2 P1 and P1, P2 are absolute pressure (psia) P1 = inlet pressure, P2 = outlet pressure
Size inInches | Gate or Bellow Seal ValvesStandard Port | Full PortGate Valves | Globe Valves | Bellow Seal GlobeValves | |||
150 – 800 | 900 – 1500 | 150 – 1500 | 150 – 800 | 900 – 1500 | 150 – 800 | 1500 – 2500 | |
1/4, 3/8 | 2.6 | 2.6 | 2.6 | 2 | 2 | 1.5 | – |
1/2 | 7 | 14 | 14 | 3 | 3 | 2.5 | 5 |
3/4 | 14 | 14 | 22 | 4 | 4 | 3.5 | 7 |
1 | 30 | 30 | 34 | 6 | 8 | 6 | 9 |
1.1/4 | 85 | 85 | 92 | 14 | 19 | 12 | 30 |
1.1/2 | 100 | 100 | 110 | 14 | 19 | 12 | 34 |
2 | 160 | 160 | 200 | 33 | 29 | 28 | 38 |
API 600-Cast Steel Valves( Flanges, Weights & Cv Flow Coefficients)
ASMEClass | Dimensions in Inches | Weight in Lbs. | CV Flow | |||||||||
SizeIN | FlangeDia | BoltCircle | HoleDia | No.of | BoltsDia | Gate | Globe | |||||
Dia | Holes | Bw | Ff | Bw | Ff | Gate | Globe | |||||
150# Raised Face | 2 | 6.00 | 4.75 | 0.75 | 4 | 5/8 | 42 | 48 | 48 | 55 | 260 | 35 |
2.1/2 | 7.00 | 5.50 | 0.75 | 4 | 5/8 | 50 | 59 | 54 | 58 | 420 | 60 | |
3 | 7.50 | 6.00 | 0.75 | 4 | 5/8 | 67 | 78 | 82 | 102 | 625 | 92 | |
4 | 9.00 | 7.50 | 0.75 | 8 | 5/8 | 97 | 117 | 120 | 152 | 1150 | 180 | |
6 | 11.00 | 9.50 | 0.88 | 8 | 3/4 | 180 | 198 | 240 | 280 | 2650 | 430 | |
8 | 13.50 | 11.75 | 0.88 | 8 | 3/4 | 278 | 319 | 405 | 435 | 4850 | 810 | |
10 | 16.00 | 14.25 | 1.00 | 12 | 7/8 | 456 | 515 | 500 | 550 | 7750 | 1400 | |
12 | 19.00 | 17.00 | 1.00 | 12 | 7/8 | 646 | 735 | 1050 | 1200 | 11500 | 1950 | |
14 | 21.00 | 18.75 | 1.13 | 12 | 1 | 875 | 954 | 1700 | 1850 | 14000 | 2500 | |
16 | 23.50 | 21.25 | 1.13 | 16 | 1 | 1120 | 1200 | 2300 | 2500 | 19000 | 3400 | |
18 | 25.00 | 22.75 | 1.25 | 16 | 1.1/8 | 1485 | 1570 | 2640 | 2850 | 24000 | 4500 | |
20 | 27.50 | 25.00 | 1.25 | 20 | 1.1/8 | 1825 | 1910 | 31000 | ||||
24 | 32.00 | 29.50 | 1.38 | 20 | 1.1/4 | 2870 | 2690 | 45000 | ||||
300# Raised Face | 2 | 6.50 | 5.00 | 0.75 | 8 | 5/8 | 46 | 60 | 45 | 60 | 260 | 35 |
2.1/2 | 7.50 | 5.88 | 0.88 | 8 | 3/4 | 55 | 76 | 63 | 72 | 420 | 60 | |
3 | 8.25 | 6.62 | 0.88 | 8 | 3/4 | 90 | 115 | 88 | 114 | 625 | 92 | |
4 | 10.00 | 7.88 | 0.88 | 8 | 3/4 | 136 | 166 | 130 | 171 | 1150 | 180 | |
6 | 12.50 | 10.62 | 0.88 | 12 | 3/4 | 245 | 314 | 261 | 337 | 2650 | 430 | |
8 | 15.00 | 13.00 | 1.00 | 12 | 3/4 | 415 | 506 | 447 | 565 | 4850 | 810 | |
10 | 17.50 | 15.25 | 1.13 | 16 | 1 | 646 | 762 | 1000 | 1150 | 7750 | 1325 | |
12 | 20.50 | 17.75 | 1.25 | 16 | 1.1/8 | 900 | 1100 | 1300 | 1550 | 11500 | 1950 | |
14 | 23.00 | 20.25 | 1.25 | 20 | 1.1/8 | 1392 | 1720 | 1800 | 2100 | 14000 | 2500 | |
16 | 25.50 | 22.50 | 1.38 | 20 | 1.1/4 | 1870 | 2220 | 2300 | 2700 | 19000 | 3400 | |
18 | 28.00 | 24.75 | 1.38 | 24 | 1.1/4 | 2405 | 2960 | 2640 | 3200 | 23500 | 4500 | |
20 | 30.50 | 27.00 | 1.38 | 24 | 1.1/4 | 3260 | 3700 | 30000 | ||||
24 | 36.00 | 32.00 | 1.63 | 24 | 1.1/2 | 4250 | 5100 | 44000 | ||||
600# Raised Face | 2 | 6.50 | 5.00 | 0.75 | 8 | 5/8 | 60 | 72 | 60 | 72 | 260 | 35 |
2.1/2 | 7.50 | 5.88 | 0.88 | 8 | 3/4 | 89 | 102 | 89 | 100 | 420 | 60 | |
3 | 8.25 | 6.62 | 0.88 | 8 | 3/4 | 130 | 157 | 130 | 150 | 625 | 92 | |
4 | 10.75 | 8.50 | 1.00 | 8 | 7/8 | 224 | 275 | 213 | 285 | 1150 | 180 | |
6 | 14.00 | 11.50 | 1.13 | 12 | 1 | 394 | 540 | 415 | 515 | 2650 | 430 | |
8 | 16.50 | 13.75 | 1.25 | 12 | 1.1/8 | 726 | 884 | 1050 | 1220 | 4850 | 800 | |
10 | 20.00 | 17.00 | 1.38 | 16 | 1.1/8 | 1125 | 1405 | 1550 | 1830 | 7750 | 125 | |
12 | 22.00 | 19.25 | 1.38 | 20 | 1.1/4 | 1490 | 1812 | 11500 | ||||
14 | 23.75 | 20.75 | 1.50 | 20 | 1.3/8 | 2200 | 2500 | 13000 | ||||
16 | 27.00 | 23.75 | 1.62 | 20 | 1.1/2 | 3000 | 3700 | 18000 |