To select the meter size: See Table 9.2 to find meter sizes within the velocity of 0.3 to 32.8 ft/s (0.1 to 10m/s)
for a specified full-scale (measuring range high limit) flow. Select one that has its
full-scale velocity between 3.0 and 10 ft/s (1 and 3m/s).
Note: Make sure the full-scale flow rate used for the final planning stage stays within
32.8 ft/s (10m/s) in terms of flow velocity.
Table 9.2 Flow velocity vs. flow volume
Unit: gal/min
Flow rate Size
(inch)
0.3 ft/s 0.98 ft/s 3.0ft/s 10 ft/s 32.8 ft/s
1/2'' 0.2778 0.8403 2.561 8.532 28.01
1'' 0.7780 2.334 7.115 23.72 77.81
1 1/2'' 1.991 5.975 18.210 60.71 199.2
2'' 3.112 9.337 28.460 94.86 311.2
3'' 7.965 23.90 72.850 242.8 796.7
4'' 12.45 37.35 113.8 379.4 1,245
6'' 28.01 84.03 256.1 853.8 2,801
8'' 49.80 149.4 455.3 1,518 4,980
Unit: m3/h
Flow rate Size
(mm)
0.1m/s 0.3m/s 1m/s 3m/s 10m/s
15 0.0631 0.1908 0.6361 1.908 6.361
25 0.1767 0.5301 1.767 5.301 17.67
40 0.4523 1.357 4.523 13.57 45.23
50 0.7067 2.120 7.067 21.20 70.67
80 1.809 5.428 18.09 54.28 180.9
100 2.827 8.482 28.27 84.82 282.7
150 6.361 19.08 63.61 190.8 636.1
200 11.31 33.93 113.1 229.3 1,131
