John Wood Takagi - 240H-340H-540H - Manual (Page 21)

21
Page
-Natural Gas Supply Piping-
Maximum delivery Capacity of Cubic Feet of Gas per Hour of IPS Pipe carrying Natural Gas with 0.60 Specific Gravity
Based on Pressure Drop of 0.5" W.C.
Based on Energy Content of 1,000 BTU/Cubic ft.: The water heater requires 160 Cubic ft./hr for the T-H3J-DV /
240H, 180 Cubic ft./hr for the T-H3S-DV / 340H, and 199 Cubic ft./hr for the T-H3-DV / 540H.
-Propane (LP) Supply Piping-
Maximum Capacity of Propane (LP) Based on 11" W.C. supply pressure at a 0.5" W.C. pressure drop
Pipe Size Length
Diameter 10' 20' 30' 40' 50' 60' 70' 80' 90' 100' 125' 150' 200'
3/4" 363 249 200 171 152 138 127 118 111 104 93 84 72
1" 684 470 377 323 286 259 239 222 208 197 174 158 135
1 1/4" 1,404 965 775 663 588 532 490 456 428 404 358 324 278
1 1/2" 2,103 1,445 1,161 993 880 798 734 683 641 605 536 486 416
2" 4,050 2,784 2,235 1,913 1,696 1,536 1,413 1,315 1,234 1,165 1,033 936 801
Unit: Cubic Feet per Hour
Based on Energy Content of 1,000 BTU/Cubic ft:
Divide each appliance's BTU requirement by 1,000 BTU/h to get the appliances Cubic Ft. requirement.
Take into account the distance the appliance is from the gas meter, look in the above gas chart to properly size the line.
For sections of the gas line supplying gas to more than one appliance (Ex: Point A to Point B), add up the cubic ft.
requirements of the appliances that are being supplied by that section, and size to the farthest appliance.
For Example: The section from A to B supplies gas to the furnace, range and dryer. Adding up the BTU requirements and
dividing by 1,000 yields a cubic ft. requirement of 220 cubic ft. of gas. The farthest appliance is the range, which is 50 ft.
away from the meter. Looking at the above chart, and under the column of 50 ft., Section A to B needs to be 1" in order to
supply 220 cubic ft.
Installation
Installation Manual
Water
Heater
199,000 BTU/h
Dryer
35,000 BTU/h
Gas Meter
Furnace
120,000 BTU/h
Range
65,000 BTU/h
A B
C
10' Length
1/2" Pipe Size
15' Length
1/2" Pipe Size
15' Length
1" Pipe Size
10' Length
3/4" Pipe Size
10' Length
1" Pipe Size 5' Length
1-1/4" Pipe Size
10' Length
3/4" Pipe Size
5' Length
1-1/4" Pipe Size
Gas Sizing Example
(Natural Gas)
Unit: kBTU per Hour
Pipe Size Length
Diameter 10' 20' 30' 40' 50' 60' 70' 80' 90' 100' 125' 150' 200'
3/4" 567 393 315 267 237 217 196 185 173 162 146 132 112
1" 1,071 732 590 504 448 409 378 346 322 307 275 252 213
1 1/4" 2,205 1,496 1,212 1,039 913 834 771 724 677 630 567 511 440
1 1/2" 3,307 2,299 1,858 1,559 1,417 1,275 1,181 1,086 1,023 976 866 787 675
2" 6,221 4,331 3,465 2,992 2,646 2,394 2,205 2,047 1,921 1,811 1,606 1,496 1,260