Valve Selection

Valve Selection Guide

Balancing Valves should be selected according to GPM flows, not line sizes.
Valve Size Minimum Flow Nominal Range of Flow Maximum Flow
Nominal Dimensions
Inches mm GPM/LPM GPM/LPM GPM/LPM
1/2 DN 15 0.14 / .52 0.5 – 3.8 / 1.89 – 14.36 12.1 / 45.7
3/4 DN 20 .26 / .98 3.8 – 5.5 / 14.36 – 20.8 17.4 / 65.7
1 DN 25 .37 / 1.38 5.5 – 9.5 / 20.8 – 36 30 / 113.4
1 1/4 DN 32 .60 / 2.28 9.5 – 14 / 36 – 53 44.6 / 169
1 1/2 DN 40 .91 / 3.46 14 – 20 / 53 – 76 66.4 / 251
2 DN 50 1.52 / 5.76 20 – 33 / 76 – 125 107.2 / 406
2 1/2 DN 65 2.13 / 8.07 33 – 100 / 125 – 378 318.3 / 1205
3 DN 80 4.19 / 15.9 100 – 117 / 378 – 442 374.5 / 1418
4 DN 100 6.09 / 23 117 – 200 / 442 – 756 646.8 / 2448
5 DN 125 7.61 / 28.8 200 – 320 / 756 – 1210 1025 / 3879
6 DN 150 13.7 / 51.9 320 – 440 / 1210 – 1663 1447 / 5477
8 DN 200 30.3 / 114 440 – 650 / 1663 – 2460 2100 / 7940
10 DN 250 76.3 / 289 650 – 1300 / 2460 – 4915 4050 / 15300
12 DN 300 76.3 / 289 1300 – 1600 / 4915 – 6050 4750 / 17590

Correction For Liquids
Applies to liquids other than water. Correct the measured flow (q) by the density (γ) according to this formula.

Sizing a Balancing Valve
When the differential pressure and design flow are known, use this formula to calculate Cv value.