Water Control Valves - Kv Calculation
The table below can be used to estimate the Kv values for process control valves used in water systems.
- Go to the left column and select the pressure drop for the valve
- Go right in table close to the actual water flow. Interpolate to find the approximately Kv value
For full table - rotate the screen!
Pressure drop | Water flow (kg/h) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
36 | 72 | 108 | 144 | 180 | 360 | 720 | 1080 | 1440 | 1800 | 3600 | ||
(kPa) | (bar) | Water flow (kg/s) | ||||||||||
0.01 | 0.02 | 0.03 | 0.04 | 0.05 | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 1 | ||
1 | 0.01 | 0.36 | 0.72 | 1.1 | 1.4 | 1.8 | 3.6 | 7.2 | 10.8 | 14.4 | 18.0 | 36.0 |
2 | 0.02 | 0.25 | 0.51 | 0.76 | 1.0 | 1.3 | 2.6 | 5.1 | 7.6 | 10.2 | 12.7 | 25.5 |
3 | 0.03 | 0.21 | 0.42 | 0.62 | 0.83 | 1.0 | 2.1 | 4.2 | 6.2 | 8.3 | 10.4 | 20.8 |
4 | 0.04 | 0.18 | 0.36 | 0.54 | 0.72 | 0.90 | 1.8 | 3.6 | 5.4 | 7.2 | 9.0 | 18.0 |
5 | 0.05 | 0.16 | 0.32 | 0.48 | 0.64 | 0.80 | 1.6 | 3.2 | 4.8 | 6.4 | 8.1 | 16.1 |
10 | 0.1 | 0.11 | 0.23 | 0.34 | 0.46 | 0.57 | 1.1 | 2.3 | 3.4 | 4.6 | 5.7 | 11.4 |
20 | 0.2 | 0.08 | 0.16 | 0.24 | 0.32 | 0.40 | 0.80 | 1.6 | 2.4 | 3.2 | 4.0 | 8.1 |
30 | 0.3 | 0.07 | 0.13 | 0.2 | 0.26 | 0.33 | 0.66 | 1.3 | 2.0 | 2.6 | 3.3 | 6.6 |
40 | 0.4 | 0.06 | 0.11 | 0.17 | 0.23 | 0.28 | 0.57 | 1.1 | 1.7 | 2.3 | 2.9 | 5.7 |
50 | 0.5 | 0.05 | 0.10 | 0.15 | 0.20 | 0.25 | 0.51 | 1.0 | 1.5 | 2.0 | 2.6 | 5.1 |
100 | 1 | 0.04 | 0.07 | 0.11 | 0.14 | 0.18 | 0.36 | 0.72 | 1.1 | 1.4 | 1.8 | 3.6 |
200 | 2 | 0.03 | 0.05 | 0.08 | 0.10 | 0.13 | 0.25 | 0.51 | 0.76 | 1.0 | 1.3 | 2.6 |
300 | 3 | 0.02 | 0.04 | 0.06 | 0.08 | 0.10 | 0.21 | 0.42 | 0.62 | 0.83 | 1.0 | 2.1 |
400 | 4 | 0.02 | 0.04 | 0.05 | 0.07 | 0.09 | 0.18 | 0.36 | 0.54 | 0.72 | 0.9 | 1.8 |
500 | 5 | 0.02 | 0.03 | 0.05 | 0.06 | 0.08 | 0.16 | 0.32 | 0.48 | 0.64 | 0.8 | 1.6 |
1000 | 10 | 0.01 | 0.02 | 0.03 | 0.05 | 0.06 | 0.11 | 0.23 | 0.34 | 0.46 | 0.57 | 1.1 |
2000 | 20 | 0.01 | 0.02 | 0.02 | 0.03 | 0.04 | 0.08 | 0.16 | 0.24 | 0.32 | 0.40 | 0.80 |
3000 | 30 | 0.01 | 0.01 | 0.02 | 0.03 | 0.03 | 0.07 | 0.13 | 0.20 | 0.26 | 0.33 | 0.66 |
4000 | 40 | 0.01 | 0.01 | 0.02 | 0.02 | 0.03 | 0.06 | 0.11 | 0.17 | 0.23 | 0.28 | 0.57 |
For full table - rotate the screen!
Pressure drop | Water flow (kg/h) | |||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
7200 | 10800 | 14400 | 18000 | 36000 | 72000 | 108000 | 144000 | 180000 | 360000 | 720000 | ||
(kPa) | (bar) | Water flow (kg/s) | ||||||||||
2 | 3 | 4 | 5 | 10 | 20 | 30 | 40 | 50 | 100 | 200 | ||
1 | 0.01 | 72.0 | 108 | 144 | 180 | 360 | 720 | 1080 | 1440 | 1800 | 3600 | 7200 |
2 | 0.02 | 50.9 | 76.4 | 102 | 127 | 254 | 509 | 763 | 1019 | 1273 | 2546 | 5091 |
3 | 0.03 | 41.6 | 62.4 | 83.1 | 103 | 207 | 415 | 623 | 831 | 1039 | 2078 | 4157 |
4 | 0.04 | 36.0 | 54.0 | 72.0 | 90.0 | 180 | 360 | 540 | 720 | 900 | 1800 | 3600 |
5 | 0.05 | 32.2 | 48.3 | 64.4 | 80.5 | 161 | 321 | 483 | 644 | 805 | 1610 | 3220 |
10 | 0.1 | 22.8 | 34.2 | 45.5 | 56.9 | 113 | 227 | 342 | 455 | 569 | 1138 | 2277 |
20 | 0.2 | 16.1 | 24.2 | 32.2 | 40.3 | 80.5 | 161 | 242 | 322 | 402 | 805 | 1610 |
30 | 0.3 | 13.2 | 19.7 | 26.3 | 32.9 | 65.7 | 131 | 197 | 263 | 329 | 657 | 1315 |
40 | 0.4 | 11.4 | 17.1 | 22.8 | 28.5 | 56.9 | 114 | 171 | 228 | 285 | 569 | 1138 |
50 | 0.5 | 10.2 | 15.3 | 20.4 | 25.5 | 50.9 | 102 | 153 | 204 | 255 | 509 | 1018 |
100 | 1 | 7.2 | 10.8 | 14.4 | 18.0 | 36.0 | 72.0 | 108 | 144 | 180 | 360 | 720 |
200 | 2 | 5.1 | 7.6 | 10.2 | 12.7 | 25.5 | 50.9 | 76.4 | 102 | 127 | 255 | 509 |
300 | 3 | 4.2 | 6.2 | 8.3 | 10.4 | 20.8 | 41.6 | 62.4 | 83.1 | 104 | 208 | 416 |
400 | 4 | 3.6 | 5.4 | 7.2 | 9.0 | 18.0 | 36.0 | 54.0 | 72.0 | 90.0 | 180 | 360 |
500 | 5 | 3.2 | 4.8 | 6.4 | 8.1 | 16.1 | 32.2 | 48.3 | 64.4 | 80.5 | 161 | 322 |
1000 | 10 | 2.3 | 3.4 | 4.6 | 5.7 | 11.4 | 22.8 | 34.2 | 45.5 | 56.9 | 114 | 228 |
2000 | 20 | 1.6 | 2.4 | 3.2 | 4.0 | 8.1 | 16.1 | 24.2 | 32.2 | 40.3 | 80.5 | 161 |
3000 | 30 | 1.3 | 2.0 | 2.6 | 3.3 | 6.6 | 13.2 | 19.7 | 26.3 | 32.9 | 65.7 | 131 |
4000 | 40 | 1.1 | 1.7 | 2.3 | 2.9 | 5.7 | 11.4 | 17.1 | 22.8 | 28.5 | 56.9 | 114 |
Example - Kv for a Water Control Valve
For a water control valve with
- pressure drop 2 bar
- water flow 1 kg/s
- the Kv value should be approximately 2.6 according the table above.
Kv can be calculated as:
Kv = q / (dp)1/2 (1)
where
Kv = Kv value
q = water flow (m3/h)
dp = pressure drop (bar)
Related Topics
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Control Valve terminology, bodies, trim, flow characteristics, Cv and Kv sizing, noise, actuators, positioners and more.
• Process Control Systems
Instrumentation, design and documentation of process control systems.
• Water Systems
Design of hot and cold water service and utility systems with properties, capacities, sizing of pipe lines and more.
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