Installation Guide

Natural Gas Sizing Tables

Table 7.1 Low Pressure (6 - 7 in w.c. with 0.5 in drop)

Maximum Capacity of HOME-FLEX® CSST in Cubic Feet per Hour (CFH) of Natural Gas (Approximate 1000 BTU per cubic foot)

Minimum Gas Pressure: 6-7 in w.c. (¼ PSI) Pressure Drop: 0.5 in w.c. (Based on a 0.6 specic gravity of gas)

Tube Size EHD

Tubing Length (ft)

5 10 15 20 25 30 40 50 60 70 75 80 90 100 125 150 200 300 400 500

½" 18 100 71 59 51 46 42 37 33 30 28 27 26 25 24 21 19 17 14 12 11

¾" 25 283 200 163 141 127 116 100 89 82 76 73 71 67 63 57 52 45 37 32 28

1" 31 626 425 338 288 254 230 195 172 156 143 137 133 124 117 103 93 79 63 54 47

Equivalent Hydraulic Diameter (EHD): A theoretical sizing which is used to compare the

hydraulic performance between manufacturers. A higher EHD number indicates greater

ow capacity of piping.

Tables include losses for four 90 degree bends and two (2) end ttings. Tubing runs with

larger numbers of bends and/or tting shall be increased by an equivalent length of tubing

according to the following formula: L = 1.3 x (n) where L is the additional length of tubing

necessary and n is the number of additional ttings and/or bends.

Table 7.2 Low Pressure (6 - 7 in w.c. with 1 in drop)

Maximum Capacity of HOME-FLEX® CSST in Cubic Feet per Hour (CFH) of Natural Gas (Approximate 1000 BTU per cubic foot)

Minimum Gas Pressure: 6-7 in w.c. (¼ PSI) Pressure Drop: 1 in w.c. (Based on a 0.6 specic gravity of gas)

Tube Size EHD

Tubing Length (ft)

5 10 15 20 25 30 40 50 60 70 75 80 90 100 125 150 200 300 400 500

½" 18 132 95 79 69 62 57 50 45 41 38 37 36 34 32 29 27 23 19 17 15

¾" 25 406 287 234 203 182 166 143 128 117 108 105 101 96 91 81 74 64 52 45 41

1" 31 925 627 500 426 376 339 289 255 230 211 203 196 183 173 153 138 117 93 80 70