Instructions:
- Determine the total gas demand for the system by adding up the BTU/hr input from the appliance nameplates, and adding demand as appropriate for future appliances.
- For second, single or integral twin stage piping.
- Measure length of piping required from the outlet of the regulator to the appliance furthest away. No other length is necessary to do the sizing.
- Make a simple sketch of the piping, as shown.
-
Determine the capacity to be handled by each section of piping. For example, the capacity of the line between a and b must handle the total demand of all appliances A, B and C; the capacity of the line from c to d must handle only appliance B, etc.
- Using Table 4, select the proper size of
tubing or pipe for each section
of piping,
using values in BTU/hr for
the length determined
from stem #2-A. If exact length
is not on
the chart use the next longer
length. Do
not use any other length for
this purpose!
Simply select the size that
shows at least
as much capacity as needed
for each piping
section.
- For piping between first and second stage regulators.
- For a simple system with only one second stage regulator, merely measure the length of piping required between outlet of of first stage regulator and inlet of second stage regulator. Select piping or tubing required from Table 1, 2 or 3.
Example 1
Determine the sizes of piping or tubing required for the single-stage LP-Gas installation shown.
Total piping length = 84 feet (use table 4 @ 90 feet)
From a to b, demand = 200,000 + 38,000 + 65,000 + 35,000 = 338,000 BTU/hr - Use 1 inch pipe
From b to c, demand = 38,000 + 65,000 + 35,000 = 138,000 BTU/hr - Use 3/4 inch pipe or 7/8" pipe
From c to d, demand = 65,000 + 35,000 = 100,000 BTU/hr - Use 3/4 inch pipe or 3/4" tubing
From d to e, demand = 35,000 = Use 1/2 inch piping or 5/8" tubing
From b to f, demand = 200,000 = Use 1 inch pipe
From c to g, demand = 38,000 = Use 1/2 inch pipe or 5/8" tubing
From d to h, demand = 65,000 = Use 1/2 inch pipe or 3/4" tubing
Example 2
Determine the sizes of piping or tubing required for the two stage LP-Gas installation shown.
Total first stage piping length = 26 feet; first stage regulation setting is 10 psig (use Table 1 or 3, @ 30 feet)
From a a to a, demand = 338,000 BTU /hr - Use 1/2 inch pipe, 1/2 inch tubing or 1/2 inch T plastic pipe.
Total second stage piping length = 58 feet (use Table 4, @60 feet)
From a to b, demand = 338,000 BTU /hr - Use 1 inch pipe
From b to c, demand = 138,000 BTU /hr - Use 3/4 inch pipe or 7/8" tubing
From c to d, demand = 100,000 BTU /hr - Use 1/2 inch pipe or 3/4" tubing
From d to e , demand = 35,000 = Use 1/2 inch pipe or 1/2" tubing
From b to f , demand = 200,000 = Use 3/4 inch pipe
From c to g , demand = 38,000 = Use 1/2 inch pipe or 5/8" tubing
From d to h , demand = 65,000 = Use 1/2 inch pipe or 5/8" tubing
Table 1 - First Stage Piping Sizing
| Pipe or Tube Size in Inches | Length in Feet | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
| Copper (O.D) | 3/8 1/2 5/8 3/4 |
558 1387 2360 3993 |
383 870 1622 2475 |
309 700 1303 2205 |
265 599 1115 1887 |
235 531 988 1672 |
213 481 896 1515 |
196 443 824 1394 |
182 412 767 1297 |
171 386 719 1217 |
161 365 679 1149 |
| Pipe Size | 1/2 3/4 1 1-1/4 1-1/2 2 |
3339 6982 13153 27004 40461 77924 |
2295 4799 9040 18560 27809 53556 |
1843 3854 7259 14904 22331 43008 |
1577 3298 6213 12756 19113 36809 |
1398 2923 5507 11306 16939 32623 |
1267 2649 4989 10244 15348 29559 |
1165 2437 4590 9424 14120 27194 |
1084 2267 4270 8767 13136 25299 |
1017 2127 4007 8226 12325 23737 |
961 2009 3785 7770 11642 22422 |
| Pipe or Tube Size in Inches | Length in Feet | 125 | 150 | 175 | 200 | 225 | 250 | 275 | 300 | 350 | 400 |
| Copper (O.D) | 3/8 1/2 5/8 3/4 |
142 323 601 1018 |
130 293 546 923 |
118 269 502 843 |
111 241 467 790 |
104 235 438 740 |
90 222 414 700 |
89 211 393 664 |
89 201 375 634 |
82 185 345 584 |
76 172 321 543 |
| Pipe Size | 1/2 3/4 1 1-1/4 1-1/2 2 |
852 1780 3354 6887 10318 19871 |
772 1613 3039 6240 9349 18005 |
710 1484 2796 5741 8601 16564 |
660 1381 2601 5340 8002 15410 |
619 1296 2441 5011 7508 14459 |
585 1224 2305 4733 7092 13658 |
556 1162 2190 4495 6735 12971 |
530 1109 2089 4289 6426 12375 |
488 1020 1922 3945 5911 11385 |
454 949 1788 3670 5499 10591 |
Note:
Length of pipe is total length from outlet of first stage regulator to inlet of second stage regulator (or inlet of second stage regulator furthest away).
- To allow 2 PSIG pressure drop, multiply total gas demand by .707, and use capacities from table.
- For different first stage pressures, multiply
total gas demand by the following
factors,
and use capacities from table.
First Stage Pressure PSIG Multiply By 20 0.844 15 0.912
5 PSIG Inlet with 1 PSIG Pressure Drop
Maximum capacity of pipe or tubing, in thousands of BTU/hr of LP-Gas
| Pipe or Tube Size in Inches | Length in Feet | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
| Copper (D.O) | 3/8 1/2 5/8 3/4 |
454 938 1907 3334 |
312 644 1311 2291 |
251 518 1053 1840 |
215 443 901 1575 |
190 393 799 1396 |
172 356 724 1265 |
159 327 666 1163 |
148 304 619 1082 |
138 286 581 1015 |
131 270 549 959 |
| Pipe Size | 1/2 3/4 1 1-1/4 1-1/2 2 |
2946 6161 11605 23826 35699 68753 |
2025 4234 7976 16376 24536 47253 |
1626 3400 6405 13150 19703 37946 |
1392 2910 5482 11255 16863 32477 |
1233 2579 4859 9975 14946 28784 |
1118 2337 4402 9038 13542 26080 |
1028 2150 4050 8315 12458 23999 |
957 2000 3768 3768 7735 11590 |
897 1877 3535 7258 10875 20943 |
848 1773 3339 6856 10272 19783 |
| Pipe or Tube Size in Inches | Length in Feet | 125 | 150 | 175 | 200 | 225 | 250 | 275 | 300 | 350 | 400 |
| Copper (D.O) | 3/8 1/2 5/8 3/4 |
116 239 486 850 |
105 217 441 770 |
97 199 405 709 |
90 185 377 569 |
84 174 354 619 |
80 164 334 584 |
76 156 318 555 |
72 149 303 529 |
66 137 279 487 |
62 127 259 453 |
| Pipe Size | 1/2 3/4 1 1-1/4 1-1/2 2 |
751 1571 2956 6076 9104 17533 |
681 1424 2682 5505 8249 15886 |
626 1310 2467 5065 7589 14615 |
583 1218 2295 4712 7060 13597 |
547 1143 2153 4421 6624 12757 |
516 1080 2034 4176 6257 12051 |
490 1026 1932 3966 5943 11445 |
468 978 1843 3784 5669 10919 |
430 900 1696 3481 5216 10045 |
400 837 1577 3238 4852 9345 |
Note:
Length of pipe is total length from outlet of first stage to inlet of second stage regulator (or inlet of second stage regulator furthest away).
To allow 2 PSIG pressure drop, multiply the total gas demand by .707, and use capacities from table
Table 3 - First Stage Plastic Tubing Sizing
10 PSIG Inlet with a 1 PSIG Pressure Drop
Maximum capacity of plastic tubing in thousands of BTU/hr of LP-Gas
| Plastic Tube Size NPS |
SDR | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
| 1/2 T 1/2 3/4 1 T 1 T 1 1-1/4 2 |
7 9.33 11 11.5 12.5 11 10 11 |
1387 3901 7811 9510 10002 14094 24416 66251 |
954 2681 5369 6536 6874 9687 16781 45534 |
766 2153 4311 5249 5520 7779 13476 36566 |
655 1843 3690 4492 4725 6658 11534 31295 |
581 1633 3270 3981 4187 5901 11534 31295 |
581 1633 3270 3981 4187 5901 10222 27737 |
526 1480 2963 3607 3794 5346 9262 25131 |
484 1361 2726 3319 3490 4919 8521 23120 |
423 1188 2379 2897 3046 4293 7438 20181 |
399 1122 2248 2736 2878 4055 7026 19063 |
| Plastic Tube Size NPS |
SDR | 125 | 150 | 175 | 200 | 225 | 250 | 275 | 300 | 350 | 400 |
| 1/2 T 1/2 3/4 1 T 1 T 1 1-1/4 2 |
7 9.33 11 11.5 12.5 11 10 11 |
354 995 1992 2425 2551 3594 6226 16895 |
321 901 1805 2197 2311 3257 5642 15308 |
295 829 1660 2022 2126 2996 5190 14084 |
274 772 1545 1881 1978 2787 4829 13102 |
257 724 1449 1765 1856 2615 4531 12293 |
243 684 1369 1667 1753 2470 4280 11028 |
231 650 1300 1583 1665 2346 4064 11028 |
220 620 1241 1510 1588 2238 3878 10521 |
203 570 1141 1389 1461 2059 3567 9680 |
189 530 1062 1293 1359 1916 3318 9005 |
Total Length of piping from outlet of first stage regulator to inlet of second stage regulator or to an inlet of a second stage regulator furthest away.
Table 4 - Second, Single or Integral Stage Pipe Sizing
11 inches Water Column Inlet with a 1/2 inch Water Column Drop
Maximum capacity of pipe or tubing in thousands of BTU/hr of LP- Gas
| Pipe or Tube Size in Inches | Length in Feet | 10 | 20 | 30 | 40 | 50 | 60 | 70 | 80 | 90 | 100 |
| Copper (O.D) | 3/8 1/2 5/8 3/4 7/8 |
49 110 206 348 536 |
34 76 141 239 368 |
27 61 114 192 296 |
23 52 97 164 253 |
20 46 86 146 224 |
19 42 78 132 203 |
- 38 71 120 185 |
- 36 67 113 174 |
- 33 62 105 161 |
- 32 59 100 154 |
| Pipe Size | 1/2 3/4 1 1-1/4 1-1/2 2 |
291 608 1146 2353 3525 6789 |
200 418 788 1617 2423 4666 |
161 336 632 1299 1946 3747 |
137 287 541 1111 1665 3207 |
122 255 480 985 1476 2842 |
110 231 435 892 1337 2575 |
102 212 400 821 1230 2369 |
94 198 372 764 1144 2204 |
87 185 349 717 1074 2068 |
84 175 330 377 1014 1954 |
| Pipe or Tube Size in Inches | Length in Feet | 125 | 150 | 175 | 200 | 225 | 250 | 275 | 300 | 350 | 400 |
| Copper (O.D) | 3/8 1/2 5/8 3/4 7/8 |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
- - - - - |
| Pipe Size | 1/2 3/4 1 1-1/4 1-1/2 2 |
74 155 292 600 899 1731 |
67 141 265 544 815 1569 |
62 129 244 500 749 1443 |
58 120 227 465 697 1343 |
54 113 213 437 654 1260 |
51 107 201 412 618 1190 |
48 101 191 392 587 1130 |
46 97 182 374 560 1078 |
43 89 167 344 515 992 |
40 83 156 320 479 923 |
Total Length of piping from outlet of regulator to appliance furthest away.
All Table Data Calculated per NFPA #54 & 58
