Appendix 2: Imperial Orifice Capacity Table (flow values in CFH)

Download this spreadsheet: BCcampus D5 Orifice Capacity Table [XLSX].
Imperial Orifice Capacity Table (flow values in CFH) – Part 1
Orifice Factor 0.90 Natural Gas Propane Butane
Sg 0.60 Sg 1.50 Sg 2.00
Drill Size Dia. In Manifold Pressure in inches of water column
1.0 3.0 3.5 4.0 7.0 10.0 11.0 10.0 11.0
80 0.0135 0.276 0.478 0.516 0.552 0.730 0.552 0.579 0.478 0.501
79 0.0145 0.318 0.551 0.595 0.636 0.842 0.636 0.667 0.551 0.578
1/64 0.0156 0.368 0.638 0.689 0.737 0.974 0.737 0.773 0.638 0.669
78 0.0160 0.387 0.671 0.725 0.775 1.025 0.775 0.813 0.671 0.704
77 0.0180 0.490 0.849 0.917 0.981 1.297 0.981 1.029 0.849 0.891
76 0.0200 0.605 1.049 1.133 1.211 1.602 1.211 1.270 1.049 1.100
75 0.0210 0.667 1.156 1.249 1.335 1.766 1.335 1.400 1.156 1.212
74 0.0225 0.766 1.327 1.433 1.532 2.027 1.532 1.607 1.327 1.392
73 0.0240 0.872 1.510 1.631 1.744 2.306 1.744 1.829 1.510 1.584
72 0.0250 0.946 1.638 1.770 1.892 2.503 1.892 1.984 1.638 1.718
71 0.0260 1.023 1.772 1.914 2.046 2.707 2.046 2.146 1.772 1.859
70 0.0280 1.187 2.055 2.220 2.373 3.139 2.373 2.489 2.055 2.155
69 0.0292 1.290 2.235 2.414 2.581 3.414 2.581 2.707 2.235 2.344
68 0.0310 1.454 2.519 2.721 2.909 3.848 2.909 3.051 2.519 2.642
1/32 0.0313 1.483 2.568 2.774 2.965 3.923 2.965 3.110 2.568 2.694
67 0.0320 1.550 2.684 2.899 3.100 4.100 3.100 3.251 2.684 2.815
Imperial Orifice Capacity Table (flow values in CFH) – Part 2
Orifice Factor 0.90 Natural Gas Propane Butane
Sg 0.60 Sg 1.50 Sg 2.00
Drill Size Dia. In Manifold Pressure in inches of water column
1.0 3.0 3.5 4.0 7.0 10.0 11.0 10.0 11.0
66 0.0330 1.648 2.855 3.083 3.296 4.361 3.296 3.457 2.855 2.994
65 0.0350 1.854 3.211 3.469 3.708 4.905 3.708 3.889 3.211 3.368
64 0.0360 1.961 3.397 3.670 3.923 5.190 3.923 4.114 3.397 3.563
63 0.0370 2.072 3.589 3.876 4.144 5.482 4.144 4.346 3.589 3.764
62 0.0380 2.185 3.785 4.089 4.371 5.782 4.371 4.584 3.785 3.970
61 0.0390 2.302 3.987 4.307 4.604 6.090 4.604 4.829 3.987 4.182
60 0.0400 2.422 4.194 4.530 4.843 6.407 4.843 5.079 4.194 4.399
59 0.0410 2.544 4.407 4.760 5.088 6.731 5.088 5.337 4.407 4.622
58 0.0420 2.670 4.624 4.995 5.340 7.064 5.340 5.600 4.624 4.850
57 0.0430 2.798 4.847 5.235 5.597 7.404 5.597 5.870 4.847 5.084
56 0.0465 3.272 5.668 6.122 6.545 8.658 6.545 6.864 5.668 5.945
3/64 0.0469 3.329 5.766 6.228 6.658 8.808 6.658 6.983 5.766 6.048
55 0.0520 4.092 7.088 7.656 8.185 10.828 8.185 8.584 7.088 7.434
54 0.0550 4.578 7.930 8.565 9.156 12.113 9.156 9.603 7.930 8.317
53 0.0595 5.358 9.280 10.024 10.716 14.176 10.716 11.239 9.280 9.733
1/16 0.0625 5.912 10.240 11.060 11.824 15.642 11.824 12.401 10.240 10.740
52 0.0635 6.103 10.570 11.417 12.205 16.146 12.205 12.801 10.570 11.086
51 0.0670 6.794 11.767 12.710 13.588 17.975 13.588 14.251 11.767 12.342
50 0.0700 7.416 12.845 13.874 14.832 19.621 14.832 15.556 12.845 13.472
49 0.0730 8.065 13.969 15.089 16.131 21.339 16.131 16.918 13.969 14.651
48 0.0760 8.742 15.141 16.354 17.484 23.129 17.484 18.337 15.141 15.880
5/64 0.0781 9.232 15.990 17.271 18.463 24.424 18.463 19.364 15.990 16.770
47 0.0785 9.326 16.154 17.448 18.653 24.675 18.653 19.563 16.154 16.942
46 0.0810 9.930 17.199 18.577 19.860 26.272 19.860 20.829 17.199 18.038
45 0.0820 10.177 17.626 19.039 20.353 26.925 20.353 21.347 17.626 18.487
Imperial Orifice Capacity Table (flow values in CFH) – Part 3
Orifice Factor 0.90 Natural Gas Propane Butane
Sg 0.60 Sg 1.50 Sg 2.00
Drill Size Dia. In Manifold Pressure in inches of water column
1.0 3.0 3.5 4.0 7.0 10.0 11.0 10.0 11.0
44 0.0860 11.194 19.388 20.941 22.387 29.616 22.387 23.480 19.388 20.334
43 0.0890 11.988 20.764 22.428 23.976 31.718 23.976 25.147 20.764 21.778
42 0.0935 13.231 22.917 24.753 26.462 35.006 26.462 27.754 22.917 24.036
3/32 0.0938 13.316 23.064 24.912 26.632 35.231 26.632 27.932 23.064 24.190
41 0.0960 13.948 24.159 26.095 27.896 36.903 27.896 29.258 24.159 25.338
40 0.0980 14.535 25.176 27.193 29.071 38.457 29.071 30.490 25.176 26.405
39 0.0995 14.984 25.953 28.032 29.967 39.643 29.967 31.430 25.953 27.219
38 0.1015 15.592 27.006 29.170 31.184 41.253 31.184 32.706 27.006 28.325
37 0.1040 16.370 28.353 30.625 32.739 43.310 32.739 34.337 28.353 29.737
36 0.1065 17.166 29.733 32.115 34.332 45.417 34.332 36.008 29.733 31.184
7/64 0.1094 18.114 31.374 33.888 36.227 47.924 36.227 37.996 31.374 32.905
35 0.1100 18.313 31.719 34.260 36.626 48.452 36.626 38.414 31.719 33.267
34 0.1110 18.647 32.298 34.886 37.295 49.336 37.295 39.115 32.298 33.875
33 0.1130 19.325 33.473 36.155 38.651 51.130 38.651 40.537 33.473 35.106
32 0.1160 20.365 35.274 38.100 40.730 53.881 40.730 42.718 35.274 36.995
31 0.1200 21.794 37.748 40.773 43.588 57.661 43.588 45.715 37.748 39.591
1/8 0.1250 23.648 40.959 44.241 47.296 62.567 47.296 49.604 40.959 42.959
30 0.1285 24.991 43.285 46.753 49.982 66.119 49.982 52.421 43.285 45.398
29 0.1360 27.993 48.485 52.370 55.986 74.063 55.986 58.719 48.485 50.852
28 0.1405 29.876 51.747 55.893 59.752 79.045 59.752 62.669 51.747 54.273
9/64 0.1406 29.919 51.821 55.973 59.838 79.158 59.838 62.758 51.821 54.350
27 0.1440 31.383 54.357 58.713 62.767 83.032 62.767 65.830 54.357 57.011
26 0.1470 32.705 56.646 61.185 65.409 86.528 65.409 68.602 56.646 59.411
25 0.1495 33.826 58.589 63.283 67.653 89.496 67.653 70.955 58.589 61.449
24 0.1520 34.967 60.565 65.418 69.934 92.514 69.934 73.348 60.565 63.521
Imperial Orifice Capacity Table (flow values in CFH) – Part 4
Orifice Factor 0.90 Natural Gas Propane Butane
Sg 0.60 Sg 1.50 Sg 2.00
Drill Size Dia. In Manifold Pressure in inches of water column
1.0 3.0 3.5 4.0 7.0 10.0 11.0 10.0 11.0
23 0.1540 35.893 62.169 67.150 71.787 94.965 71.787 75.291 62.169 65.204
5/32 0.1563 36.974 64.040 69.171 73.947 97.823 73.947 77.556 64.040 67.166
22 0.1570 37.305 64.615 69.792 74.611 98.701 74.611 78.253 64.615 67.769
21 0.1590 38.262 66.272 71.582 76.524 101.232 76.524 80.259 66.272 69.506
20 0.1610 39.231 67.949 73.394 78.461 103.794 78.461 82.291 67.949 71.266
19 0.1660 41.705 72.235 78.023 83.410 110.341 83.410 87.481 72.235 75.761
18 0.1695 43.482 75.314 81.348 86.965 115.043 86.965 91.209 75.314 78.990
11/64 0.1719 44.722 77.461 83.668 89.445 118.324 89.445 93.810 77.461 81.242
17 0.1730 45.297 78.456 84.742 90.593 119.843 90.593 95.015 78.456 82.285
16 0.1770 47.415 82.126 88.706 94.831 125.449 94.831 99.459 82.126 86.134
15 0.1800 49.036 84.933 91.739 98.073 129.738 98.073 102.860 84.933 89.079
14 0.1820 50.132 86.831 93.789 100.264 132.637 100.264 105.158 86.831 91.070
13 0.1850 51.798 89.718 96.906 103.597 137.046 103.597 108.653 89.718 94.097
3/16 0.1875 53.208 92.159 99.543 106.416 140.775 106.416 111.610 92.159 96.657
12 0.1890 54.063 93.639 101.142 108.125 143.036 108.125 113.403 93.639 98.210
11 0.1910 55.213 95.631 103.294 110.426 146.079 110.426 115.815 95.631 100.299
10 0.1935 56.668 98.151 106.015 113.335 149.929 113.335 118.867 98.151 102.942
9 0.1960 58.141 100.704 108.773 116.283 153.828 116.283 121.958 100.704 105.619
8 0.1990 59.935 103.810 112.128 119.870 158.573 119.870 125.720 103.810 108.877
7 0.2010 61.146 105.907 114.393 122.291 161.776 122.291 128.260 105.907 111.077
13/64 0.2031 62.430 108.132 116.796 124.860 165.174 124.860 130.954 108.132 113.410
6 0.2040 62.984 109.092 117.833 125.969 166.641 125.969 132.117 109.092 114.417
5 0.2055 63.914 110.703 119.572 127.828 169.101 127.828 134.067 110.703 116.106
4 0.2090 66.110 114.506 123.680 132.220 174.910 132.220 138.673 114.506 120.094
3 0.2130 68.665 118.930 128.460 137.329 181.669 137.329 144.032 118.930 124.735
Imperial Orifice Capacity Table (flow values in CFH) – Part 5
Orifice Factor 0.90 Natural Gas Propane Butane
Sg 0.60 Sg 1.50 Sg 2.00
Drill Size Dia. In Manifold Pressure in inches of water column
1.0 3.0 3.5 4.0 7.0 10.0 11.0 10.0 11.0
7/32 0.2188 72.455 125.496 135.551 144.910 191.698 144.910 151.983 125.496 131.621
2 0.2210 73.919 128.032 138.290 147.839 195.572 147.839 155.054 128.032 134.281
1 0.2280 78.676 136.271 147.190 157.352 208.157 157.352 165.032 136.271 142.922

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