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Chapter 4 Gas Piping Installations

User note:
About this chapter: Chapter 4 addresses all aspects of fuel gas piping including the allowed materials, design and sizing, piping support, pressure requirements, controls, connections to appliances, installation requirements, purging and testing. Also addressed are motor vehicle fuel dispensing systems. The overarching intent is to prevent gas leakage, overpressures and underpressures and prevent accidents.

Section 401 General

401.1 Scope

This chapter shall govern the design, installation, modification and maintenance of piping systems. The applicability of this code to piping systems extends from the point of delivery to the connections with the appliances and includes the design, materials, components, fabrication, assembly, installation, testing, inspection, operation and maintenance of such piping systems.

401.1.1 Utility Piping Systems Located Within Buildings

Utility service piping located within buildings shall be installed in accordance with the structural safety and fire protection provisions of the Arkansas Fire Prevention Code.

401.1.2 Meter Location Accessible and Acceptable

A meter location, when required, shall be provided for the building or premises to be served. The location shall be such that the meter and connections are accessible in order that the meter may be read or changed. Location, space requirements, dimensions and type of installation shall be acceptable to the gas company.

401.2 Liquefied Petroleum Gas Storage

Deleted

401.3 Modifications to Existing Systems

In modifying or adding to existing piping systems, sizes shall be maintained in accordance with this chapter.

401.4 Additional Appliances

Where an additional appliance is to be served, the existing piping shall be checked to determine if it has adequate capacity for all appliances served. If inadequate, the existing system shall be enlarged as required or separate piping of adequate capacity shall be provided.

401.5 Identification

For other than steel pipe, exposed piping shall be identified by a yellow label marked "Gas" in black letters. The marking shall be spaced at intervals not exceeding 5 feet (1524 mm). The marking shall not be required on pipe located in the same room as the equipment served.

401.6 Interconnections

Where two or more meters are installed on the same premises but supply separate consumers, the piping systems shall not be interconnected on the outlet side of the meters.

401.7 Piping Meter Identification

Piping from multiple meter installations shall be marked with an approved permanent identification by the installer so that the piping system supplied by each meter is readily identifiable.

401.8 Minimum Sizes

All pipe utilized for the installation, extension and alteration of any piping system shall be sized to supply the full number of outlets for the intended purpose and shall be sized in accordance with Section 402.

401.9 Identification

Each length of pipe and tubing and each pipe fitting, utilized in a fuel gas system, shall bear the identification of the manufacturer.
Exceptions:
  1. Steel pipe sections that are 2 feet (610 mm) and less in length and are cut from longer sections of pipe.
  2. Steel pipe fittings 2 inches (51 mm) and less in size.
  3. Where identification is provided on the product packaging or crating.
  4. Where other approved documentation is provided.

401.10 Piping Materials Standards

Piping, tubing and fittings shall be manufactured to the applicable referenced standards, specifications and performance criteria listed in Section 403 and shall be identified in accordance with Section 401.9.

Section 402 Pipe Sizing

402.1 General Considerations

Piping systems shall be of such size and so installed as to provide a supply of gas sufficient to meet the maximum demand and supply gas to each appliance inlet at not less than the minimum supply pressure required by the appliance.

402.2 Maximum Gas Demand

The volumetric flow rate of gas to be provided shall be the sum of the maximum input of the appliances served.
The total connected hourly load shall be used as the basis for pipe sizing, assuming that all appliances could be operating at full capacity simultaneously. Where a diversity of load can be established by approved engineering methods, pipe sizing shall be permitted to be based on such loads.
The volumetric flow rate of gas to be provided shall be adjusted for altitude where the installation is above 2,000 feet (610 m) in elevation.

402.3 Sizing

Gas piping shall be sized in accordance with one of the following:
  1. Pipe sizing tables or sizing equations in accordance with Section 402.4 or 402.5 as applicable.
  2. The sizing tables included in a listed piping system's manufacturer's installation instruction.
  3. Other approved engineering methods.

402.4 Sizing Tables and Equations

This section applies to piping materials other than noncorrugated stainless steel tubing. Where Tables 402.4(2) through 402.4(20) are used to size piping or tubing, the pipe length shall be determined in accordance with Section 402.4.1 or 402.4.3.
Table 402.4(1) Schedule 40 Metallic Pipe. Deleted.
Table 402.4(3) and Table 402.4(4) Schedule 40 Metallic Pipe. Deleted.
Table 402.4(6) Schedule 40 Metallic Pipe. Deleted.
Table 402.4(8) Semirigid Copper Tubing. Deleted.
Table 402.4(10) and Table 402.4(11) Semirigid Copper Tubing. Deleted.
Table 402.4(13) Semirigid Copper Tubing. Deleted.
Table 402.4(15) through 402.4(20). Deleted.
Table 402.4(23) through 402.4(37). Deleted.
TABLE 402.4(2)
SCHEDULE 40 METALLIC PIPE
Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60
PIPE SIZE (inch)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4 5 6 8 10 12
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026 5.047 6.065 7.981 10.020 11.938
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 172 360 678 1,390 2,090 4,020 6,400 11,300 23,100 41,800 67,600 139,000 252,000 399,000
20 118 247 466 957 1,430 2,760 4,400 7,780 15,900 28,700 46,500 95,500 173,000 275,000
30 95 199 374 768 1,150 2,220 3,530 6,250 12,700 23,000 37,300 76,700 139,000 220,000
40 81 170 320 657 985 1,900 3,020 5,350 10,900 19,700 31,900 65,600 119,000 189,000
50 72 151 284 583 873 1,680 2,680 4,740 9,660 17,500 28,300 58,200 106,000 167,000
60 65 137 257 528 791 1,520 2,430 4,290 8,760 15,800 25,600 52,700 95,700 152,000
70 60 126 237 486 728 1,400 2,230 3,950 8,050 14,600 23,600 48,500 88,100 139,000
80 56 117 220 452 677 1,300 2,080 3,670 7,490 13,600 22,000 45,100 81,900 130,000
90 52 110 207 424 635 1,220 1,950 3,450 7,030 12,700 20,600 42,300 76,900 122,000
100 50 104 195 400 600 1,160 1,840 3,260 6,640 12,000 19,500 40,000 72,600 115,000
125 44 92 173 355 532 1,020 1,630 2,890 5,890 10,600 17,200 35,400 64,300 102,000
150 40 83 157 322 482 928 1,480 2,610 5,330 9,650 15,600 32,100 58,300 92,300
175 37 77 144 296 443 854 1,360 2,410 4,910 8,880 14,400 29,500 53,600 84,900
200 34 71 134 275 412 794 1,270 2,240 4,560 8,260 13,400 27,500 49,900 79,000
250 30 63 119 244 366 704 1,120 1,980 4,050 7,320 11,900 24,300 44,200 70,000
300 27 57 108 221 331 638 1,020 1,800 3,670 6,630 10,700 22,100 40,100 63,400
350 25 53 99 203 305 587 935 1,650 3,370 6,100 9,880 20,300 36,900 58,400
400 23 49 92 189 283 546 870 1,540 3,140 5,680 9,190 18,900 34,300 54,300
450 22 46 86 177 266 512 816 1,440 2,940 5,330 8,620 17,700 32,200 50,900
500 21 43 82 168 251 484 771 1,360 2,780 5,030 8,150 16,700 30,400 48,100
550 20 41 78 159 239 459 732 1,290 2,640 4,780 7,740 15,900 28,900 45,700
600 19 39 74 152 228 438 699 1,240 2,520 4,560 7,380 15,200 27,500 43,600
650 18 38 71 145 218 420 669 1,180 2,410 4,360 7,070 14,500 26,400 41,800
700 17 36 68 140 209 403 643 1,140 2,320 4,190 6,790 14,000 25,300 40,100
750 17 35 66 135 202 389 619 1,090 2,230 4,040 6,540 13,400 24,400 38,600
800 16 34 63 130 195 375 598 1,060 2,160 3,900 6,320 13,000 23,600 37,300
850 16 33 61 126 189 363 579 1,020 2,090 3,780 6,110 12,600 22,800 36,100
900 15 32 59 122 183 352 561 992 2,020 3,660 5,930 12,200 22,100 35,000
950 15 31 58 118 178 342 545 963 1,960 3,550 5,760 11,800 21,500 34,000
1,000 14 30 56 115 173 333 530 937 1,910 3,460 5,600 11,500 20,900 33,100
1,100 14 28 53 109 164 316 503 890 1,810 3,280 5,320 10,900 19,800 31,400
1,200 13 27 51 104 156 301 480 849 1,730 3,130 5,070 10,400 18,900 30,000
1,300 12 26 49 100 150 289 460 813 1,660 3,000 4,860 9,980 18,100 28,700
1,400 12 25 47 96 144 277 442 781 1,590 2,880 4,670 9,590 17,400 27,600
1,500 11 24 45 93 139 267 426 752 1,530 2,780 4,500 9,240 16,800 26,600
1,600 11 23 44 89 134 258 411 727 1,480 2,680 4,340 8,920 16,200 25,600
1,700 11 22 42 86 130 250 398 703 1,430 2,590 4,200 8,630 15,700 24,800
1,800 10 22 41 84 126 242 386 682 1,390 2,520 4,070 8,370 15,200 24,100
1,900 10 21 40 81 122 235 375 662 1,350 2,440 3,960 8,130 14,800 23,400
2,000 NA 20 39 79 119 229 364 644 1,310 2,380 3,850 7,910 14,400 22,700
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Notes:
  1. NA means a flow of less than 10 cfh.
  2. Table entries have been rounded to three significant digits.
TABLE 402.4(5)
SCHEDULE 40 METALLIC PIPE
Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60
PIPE SIZE (inch)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 1,510 3,040 5,560 11,400 17,100 32,900 52,500 92,800 189,000
20 1,070 2,150 3,930 8,070 12,100 23,300 37,100 65,600 134,000
30 869 1,760 3,210 6,590 9,880 19,000 30,300 53,600 109,000
40 753 1,520 2,780 5,710 8,550 16,500 26,300 46,400 94,700
50 673 1,360 2,490 5,110 7,650 14,700 23,500 41,500 84,700
60 615 1,240 2,270 4,660 6,980 13,500 21,400 37,900 77,300
70 569 1,150 2,100 4,320 6,470 12,500 19,900 35,100 71,600
80 532 1,080 1,970 4,040 6,050 11,700 18,600 32,800 67,000
90 502 1,010 1,850 3,810 5,700 11,000 17,500 30,900 63,100
100 462 934 1,710 3,510 5,260 10,100 16,100 28,500 58,200
125 414 836 1,530 3,140 4,700 9,060 14,400 25,500 52,100
150 372 751 1,370 2,820 4,220 8,130 13,000 22,900 46,700
175 344 695 1,270 2,601 3,910 7,530 12,000 21,200 43,300
200 318 642 1,170 2,410 3,610 6,960 11,100 19,600 40,000
250 279 583 1,040 2,140 3,210 6,180 9,850 17,400 35,500
300 253 528 945 1,940 2,910 5,600 8,920 15,800 32,200
350 232 486 869 1,790 2,670 5,150 8,210 14,500 29,600
400 216 452 809 1,660 2,490 4,790 7,640 13,500 27,500
450 203 424 759 1,560 2,330 4,500 7,170 12,700 25,800
500 192 401 717 1,470 2,210 4,250 6,770 12,000 24,400
550 182 381 681 1,400 2,090 4,030 6,430 11,400 23,200
600 174 363 650 1,330 2,000 3,850 6,130 10,800 22,100
650 166 348 622 1,280 1,910 3,680 5,870 10,400 21,200
700 160 334 598 1,230 1,840 3,540 5,640 9,970 20,300
750 154 322 576 1,180 1,770 3,410 5,440 9,610 19,600
800 149 311 556 1,140 1,710 3,290 5,250 9,280 18,900
850 144 301 538 1,100 1,650 3,190 5,080 8,980 18,300
900 139 292 522 1,070 1,600 3,090 4,930 8,710 17,800
950 135 283 507 1,040 1,560 3,000 4,780 8,460 17,200
1,000 132 275 493 1,010 1,520 2,920 4,650 8,220 16,800
1,100 125 262 468 960 1,440 2,770 4,420 7,810 15,900
1,200 119 250 446 917 1,370 2,640 4,220 7,450 15,200
1,300 114 239 427 878 1,320 2,530 4,040 7,140 14,600
1,400 110 230 411 843 1,260 2,430 3,880 6,860 14,000
1,500 106 221 396 812 1,220 2,340 3,740 6,600 13,500
1,600 102 214 382 784 1,180 2,260 3,610 6,380 13,000
1,700 99 207 370 759 1,140 2,190 3,490 6,170 12,600
1,800 96 200 358 736 1,100 2,120 3,390 5,980 12,200
1,900 93 195 348 715 1,070 2,060 3,290 5,810 11,900
2,000 91 189 339 695 1,040 2,010 3,200 5,650 11,500
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
TABLE 402.4(7)
SCHEDULE 40 METALLIC PIPE
Gas Natural
Inlet Pressure 5.0 psi
Pressure Drop 3.5 psi
Specific Gravity 0.60
PIPE SIZE (inch)
Nominal 1/2 3/4 1 11/4 11/2 2 21/2 3 4
Actual ID 0.622 0.824 1.049 1.380 1.610 2.067 2.469 3.068 4.026
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 3,190 6,430 11,800 24,200 36,200 69,700 111,000 196,000 401,000
20 2,250 4,550 8,320 17,100 25,600 49,300 78,600 139,000 283,000
30 1,840 3,720 6,790 14,000 20,900 40,300 64,200 113,000 231,000
40 1,590 3,220 5,880 12,100 18,100 34,900 55,600 98,200 200,000
50 1,430 2,880 5,260 10,800 16,200 31,200 49,700 87,900 179,000
60 1,300 2,630 4,800 9,860 14,800 28,500 45,400 80,200 164,000
70 1,200 2,430 4,450 9,130 13,700 26,400 42,000 74,300 151,000
80 1,150 2,330 4,260 8,540 12,800 24,700 39,300 69,500 142,000
90 1,060 2,150 3,920 8,050 12,100 23,200 37,000 65,500 134,000
100 979 1,980 3,620 7,430 11,100 21,400 34,200 60,400 123,000
125 876 1,770 3,240 6,640 9,950 19,200 30,600 54,000 110,000
150 786 1,590 2,910 5,960 8,940 17,200 27,400 48,500 98,900
175 728 1,470 2,690 5,520 8,270 15,900 25,400 44,900 91,600
200 673 1,360 2,490 5,100 7,650 14,700 23,500 41,500 84,700
250 558 1,170 2,200 4,510 6,760 13,000 20,800 36,700 74,900
300 506 1,060 1,990 4,090 6,130 11,800 18,800 33,300 67,800
350 465 973 1,830 3,760 5,640 10,900 17,300 30,600 62,400
400 433 905 1,710 3,500 5,250 10,100 16,100 28,500 58,100
450 406 849 1,600 3,290 4,920 9,480 15,100 26,700 54,500
500 384 802 1,510 3,100 4,650 8,950 14,300 25,200 51,500
550 364 762 1,440 2,950 4,420 8,500 13,600 24,000 48,900
600 348 727 1,370 2,810 4,210 8,110 12,900 22,900 46,600
650 333 696 1,310 2,690 4,030 7,770 12,400 21,900 44,600
700 320 669 1,260 2,590 3,880 7,460 11,900 21,000 42,900
750 308 644 1,210 2,490 3,730 7,190 11,500 20,300 41,300
800 298 622 1,170 2,410 3,610 6,940 11,100 19,600 39,900
850 288 602 1,130 2,330 3,490 6,720 10,700 18,900 38,600
900 279 584 1,100 2,260 3,380 6,520 10,400 18,400 37,400
950 271 567 1,070 2,190 3,290 6,330 10,100 17,800 36,400
1,000 264 551 1,040 2,130 3,200 6,150 9,810 17,300 35,400
1,100 250 524 987 2,030 3,030 5,840 9,320 16,500 33,600
1,200 239 500 941 1,930 2,900 5,580 8,890 15,700 32,000
1,300 229 478 901 1,850 2,770 5,340 8,510 15,000 30,700
1,400 220 460 866 1,780 2,660 5,130 8,180 14,500 29,500
1,500 212 443 834 1,710 2,570 4,940 7,880 13,900 28,400
1,600 205 428 806 1,650 2,480 4,770 7,610 13,400 27,400
1,700 198 414 780 1,600 2,400 4,620 7,360 13,000 26,500
1,800 192 401 756 1,550 2,330 4,480 7,140 12,600 25,700
1,900 186 390 734 1,510 2,260 4,350 6,930 12,300 25,000
2,000 181 379 714 1,470 2,200 4,230 6,740 11,900 24,300
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Note: All table entries have been rounded to three significant digits.
TABLE 402.4(9)
SEMIRIGID COPPER TUBING
Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60
TUBE SIZE (inch)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 — —
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 27 55 111 195 276 590 1,060 1,680 3,490
20 18 38 77 134 190 406 730 1,150 2,400
30 15 30 61 107 152 326 586 925 1,930
40 13 26 53 92 131 279 502 791 1,650
50 11 23 47 82 116 247 445 701 1,460
60 10 21 42 74 105 224 403 635 1,320
70 NA 19 39 68 96 206 371 585 1,220
80 NA 18 36 63 90 192 345 544 1,130
90 NA 17 34 59 84 180 324 510 1,060
100 NA 16 32 56 79 170 306 482 1,000
125 NA 14 28 50 70 151 271 427 890
150 NA 13 26 45 64 136 245 387 806
175 NA 12 24 41 59 125 226 356 742
200 NA 11 22 39 55 117 210 331 690
250 NA NA 20 34 48 103 186 294 612
300 NA NA 18 31 44 94 169 266 554
350 NA NA 16 28 40 86 155 245 510
400 NA NA 15 26 38 80 144 228 474
450 NA NA 14 25 35 75 135 214 445
500 NA NA 13 23 33 71 128 202 420
550 NA NA 13 22 32 68 122 192 399
600 NA NA 12 21 30 64 116 183 381
650 NA NA 12 20 29 62 111 175 365
700 NA NA 11 20 28 59 107 168 350
750 NA NA 11 19 27 57 103 162 338
800 NA NA 10 18 26 55 99 156 326
850 NA NA 10 18 25 53 96 151 315
900 NA NA NA 17 24 52 93 147 306
950 NA NA NA 17 24 50 90 143 297
1,000 NA NA NA 16 23 49 88 139 289
1,100 NA NA NA 15 22 46 84 132 274
1,200 NA NA NA 15 21 44 80 126 262
1,300 NA NA NA 14 20 42 76 120 251
1,400 NA NA NA 13 19 41 73 116 241
1,500 NA NA NA 13 18 39 71 111 232
1,600 NA NA NA 13 18 38 68 108 224
1,700 NA NA NA 12 17 37 66 104 217
1,800 NA NA NA 12 17 36 64 101 210
1,900 NA NA NA 11 16 35 62 98 204
2,000 NA NA NA 11 16 34 60 95 199
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Notes:
  1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
  2. NA means a flow of less than 10 cfh.
  3. Table entries have been rounded to three significant digits.
TABLE 402.4(12)
SEMIRIGID COPPER TUBING
Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60
TUBE SIZE (inch)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 — —
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 245 506 1,030 1,800 2,550 5,450 9,820 15,500 32,200
20 169 348 708 1,240 1,760 3,750 6,750 10,600 22,200
30 135 279 568 993 1,410 3,010 5,420 8,550 17,800
40 116 239 486 850 1,210 2,580 4,640 7,310 15,200
50 103 212 431 754 1,070 2,280 4,110 6,480 13,500
60 93 192 391 683 969 2,070 3,730 5,870 12,200
70 86 177 359 628 891 1,900 3,430 5,400 11,300
80 80 164 334 584 829 1,770 3,190 5,030 10,500
90 75 154 314 548 778 1,660 2,990 4,720 9,820
100 71 146 296 518 735 1,570 2,830 4,450 9,280
125 63 129 263 459 651 1,390 2,500 3,950 8,220
150 57 117 238 416 590 1,260 2,270 3,580 7,450
175 52 108 219 383 543 1,160 2,090 3,290 6,850
200 49 100 204 356 505 1,080 1,940 3,060 6,380
250 43 89 181 315 448 956 1,720 2,710 5,650
300 39 80 164 286 406 866 1,560 2,460 5,120
350 36 74 150 263 373 797 1,430 2,260 4,710
400 33 69 140 245 347 741 1,330 2,100 4,380
450 31 65 131 230 326 696 1,250 1,970 4,110
500 30 61 124 217 308 657 1,180 1,870 3,880
550 28 58 118 206 292 624 1,120 1,770 3,690
600 27 55 112 196 279 595 1,070 1,690 3,520
650 26 53 108 188 267 570 1,030 1,620 3,370
700 25 51 103 181 256 548 986 1,550 3,240
750 24 49 100 174 247 528 950 1,500 3,120
800 23 47 96 168 239 510 917 1,450 3,010
850 22 46 93 163 231 493 888 1,400 2,920
900 22 44 90 158 224 478 861 1,360 2,830
950 21 43 88 153 217 464 836 1,320 2,740
1,000 20 42 85 149 211 452 813 1,280 2,670
1,100 19 40 81 142 201 429 772 1,220 2,540
1,200 18 38 77 135 192 409 737 1,160 2,420
1,300 18 36 74 129 183 392 705 1,110 2,320
1,400 17 35 71 124 176 376 678 1,070 2,230
1,500 16 34 68 120 170 363 653 1,030 2,140
1,600 16 33 66 116 164 350 630 994 2,070
1,700 15 31 64 112 159 339 610 962 2,000
1,800 15 30 62 108 154 329 592 933 1,940
1,900 14 30 60 105 149 319 575 906 1,890
2,000 14 29 59 102 145 310 559 881 1,830
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Notes:
  1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
  2. Table entries have been rounded to three significant digits.
TABLE 402.4(14)
SEMIRIGID COPPER TUBING
Gas Natural
Inlet Pressure 5.0 psi
Pressure Drop 3.5 psi
Specific Gravity 0.60
TUBE SIZE (inch)
Nominal K & L 1/4 3/8 1/2 5/8 3/4 1 11/4 11/2 2
ACR 3/8 1/2 5/8 3/4 7/8 11/8 13/8 — —
Outside 0.375 0.500 0.625 0.750 0.875 1.125 1.375 1.625 2.125
Inside 0.305 0.402 0.527 0.652 0.745 0.995 1.245 1.481 1.959
Length (ft) Capacity in Cubic Feet of Gas Per Hour
10 511 1,050 2,140 3,750 5,320 11,400 20,400 32,200 67,100
20 351 724 1,470 2,580 3,650 7,800 14,000 22,200 46,100
30 282 582 1,180 2,070 2,930 6,270 11,300 17,800 37,000
40 241 498 1,010 1,770 2,510 5,360 9,660 15,200 31,700
50 214 441 898 1,570 2,230 4,750 8,560 13,500 28,100
60 194 400 813 1,420 2,020 4,310 7,750 12,200 25,500
70 178 368 748 1,310 1,860 3,960 7,130 11,200 23,400
80 166 342 696 1,220 1,730 3,690 6,640 10,500 21,800
90 156 321 653 1,140 1,620 3,460 6,230 9,820 20,400
100 147 303 617 1,080 1,530 3,270 5,880 9,270 19,300
125 130 269 547 955 1,360 2,900 5,210 8,220 17,100
150 118 243 495 866 1,230 2,620 4,720 7,450 15,500
175 109 224 456 796 1,130 2,410 4,350 6,850 14,300
200 101 208 424 741 1,050 2,250 4,040 6,370 13,300
250 90 185 376 657 932 1,990 3,580 5,650 11,800
300 81 167 340 595 844 1,800 3,250 5,120 10,700
350 75 154 313 547 777 1,660 2,990 4,710 9,810
400 69 143 291 509 722 1,540 2,780 4,380 9,120
450 65 134 273 478 678 1,450 2,610 4,110 8,560
500 62 127 258 451 640 1,370 2,460 3,880 8,090
550 58 121 245 429 608 1,300 2,340 3,690 7,680
600 56 115 234 409 580 1,240 2,230 3,520 7,330
650 53 110 224 392 556 1,190 2,140 3,370 7,020
700 51 106 215 376 534 1,140 2,050 3,240 6,740
750 49 102 207 362 514 1,100 1,980 3,120 6,490
800 48 98 200 350 497 1,060 1,910 3,010 6,270
850 46 95 194 339 481 1,030 1,850 2,910 6,070
900 45 92 188 328 466 1,000 1,790 2,820 5,880
950 43 90 182 319 452 967 1,740 2,740 5,710
1,000 42 87 177 310 440 940 1,690 2,670 5,560
1,100 40 83 169 295 418 893 1,610 2,530 5,280
1,200 38 79 161 281 399 852 1,530 2,420 5,040
1,300 37 76 154 269 382 816 1,470 2,320 4,820
1,400 35 73 148 259 367 784 1,410 2,220 4,630
1,500 34 70 143 249 353 755 1,360 2,140 4,460
1,600 33 68 138 241 341 729 1,310 2,070 4,310
1,700 32 65 133 233 330 705 1,270 2,000 4,170
1,800 31 63 129 226 320 684 1,230 1,940 4,040
1,900 30 62 125 219 311 664 1,200 1,890 3,930
2,000 29 60 122 213 302 646 1,160 1,830 3,820
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Notes:
  1. Table capacities are based on Type K copper tubing inside diameter (shown), which has the smallest inside diameter of the copper tubing products.
  2. Table entries have been rounded to three significant digits.
TABLE 402.4(21)
POLYETHYLENE PLASTIC PIPE
Gas Natural
Inlet Pressure Less than 2 psi
Pressure Drop 0.5 in. w.c.
Specific Gravity 0.60
PIPE SIZE (inch)
Nominal OD 1/2 3/4 1 11/4 11/2 2 3 4
Designation SDR 9.33 SDR 11 SDR 11 SDR 10 SDR 11 SDR 11 SDR 11 SDR 11
Actual ID 0.660 0.860 1.077 1.328 1.554 1.943 2.864 3.682
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 201 403 726 1,260 1,900 3,410 9,450 18,260
20 138 277 499 865 1,310 2,350 6,490 12,550
30 111 222 401 695 1,050 1,880 5,210 10,080
40 95 190 343 594 898 1,610 4,460 8,630
50 84 169 304 527 796 1,430 3,950 7,640
60 76 153 276 477 721 1,300 3,580 6,930
70 70 140 254 439 663 1,190 3,300 6,370
80 65 131 236 409 617 1,110 3,070 5,930
90 61 123 221 383 579 1,040 2,880 5,560
100 58 116 209 362 547 983 2,720 5,250
125 51 103 185 321 485 871 2,410 4,660
150 46 93 168 291 439 789 2,180 4,220
175 43 86 154 268 404 726 2,010 3,880
200 40 80 144 249 376 675 1,870 3,610
250 35 71 127 221 333 598 1,660 3,200
300 32 64 115 200 302 542 1,500 2,900
350 29 59 106 184 278 499 1,380 2,670
400 27 55 99 171 258 464 1,280 2,480
450 26 51 93 160 242 435 1,200 2,330
500 24 48 88 152 229 411 1,140 2,200
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Note: Table entries have been rounded to three significant digits.
TABLE 402.4(22)
POLYETHYLENE PLASTIC PIPE
Gas Natural
Inlet Pressure 2.0 psi
Pressure Drop 1.0 psi
Specific Gravity 0.60
PIPE SIZE (inch)
Nominal OD 1/2 3/4 1 11/4 11/2 2 3 4
Designation SDR 9.33 SDR 11 SDR 11 SDR 10 SDR 11 SDR 11 SDR 11 SDR 11
Actual ID 0.660 0.860 1.077 1.328 1.554 1.943 2.864 3.682
Length (ft) Capacity in Cubic Feet of Gas per Hour
10 1,860 3,720 6,710 11,600 17,600 31,600 87,300 169,000
20 1,280 2,560 4,610 7,990 12,100 21,700 60,000 116,000
30 1,030 2,050 3,710 6,420 9,690 17,400 48,200 93,200
40 878 1,760 3,170 5,490 8,300 14,900 41,200 79,700
50 778 1,560 2,810 4,870 7,350 13,200 36,600 70,700
60 705 1,410 2,550 4,410 6,660 12,000 33,100 64,000
70 649 1,300 2,340 4,060 6,130 11,000 30,500 58,900
80 603 1,210 2,180 3,780 5,700 10,200 28,300 54,800
90 566 1,130 2,050 3,540 5,350 9,610 26,600 51,400
100 535 1,070 1,930 3,350 5,050 9,080 25,100 48,600
125 474 949 1,710 2,970 4,480 8,050 22,300 43,000
150 429 860 1,550 2,690 4,060 7,290 20,200 39,000
175 395 791 1,430 2,470 3,730 6,710 18,600 35,900
200 368 736 1,330 2,300 3,470 6,240 17,300 33,400
250 326 652 1,180 2,040 3,080 5,530 15,300 29,600
300 295 591 1,070 1,850 2,790 5,010 13,900 26,800
350 272 544 981 1,700 2,570 4,610 12,800 24,700
400 253 506 913 1,580 2,390 4,290 11,900 22,900
450 237 475 856 1,480 2,240 4,020 11,100 21,500
500 224 448 809 1,400 2,120 3,800 10,500 20,300
550 213 426 768 1,330 2,010 3,610 9,990 19,300
600 203 406 733 1,270 1,920 3,440 9,530 18,400
650 194 389 702 1,220 1,840 3,300 9,130 17,600
700 187 374 674 1,170 1,760 3,170 8,770 16,900
750 180 360 649 1,130 1,700 3,050 8,450 16,300
800 174 348 627 1,090 1,640 2,950 8,160 15,800
850 168 336 607 1,050 1,590 2,850 7,890 15,300
900 163 326 588 1,020 1,540 2,770 7,650 14,800
950 158 317 572 990 1,500 2,690 7,430 14,400
1,000 154 308 556 963 1,450 2,610 7,230 14,000
1,100 146 293 528 915 1,380 2,480 6,870 13,300
1,200 139 279 504 873 1,320 2,370 6,550 12,700
1,300 134 267 482 836 1,260 2,270 6,270 12,100
1,400 128 257 463 803 1,210 2,180 6,030 11,600
1,500 124 247 446 773 1,170 2,100 5,810 11,200
1,600 119 239 431 747 1,130 2,030 5,610 10,800
1,700 115 231 417 723 1,090 1,960 5,430 10,500
1,800 112 224 404 701 1,060 1,900 5,260 10,200
1,900 109 218 393 680 1,030 1,850 5,110 9,900
2,000 106 212 382 662 1,000 1,800 4,970 9,600
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound per square inch = 6.895 kPa, 1-inch water column = 0.2488 kPa, 1 British thermal unit per hour = 0.2931 W, 1 cubic foot per hour = 0.0283 m3/h, 1 degree = 0.01745 rad.
Note: Table entries have been rounded to three significant digits.

402.4.1 Longest Length Method

The pipe size of each section of gas piping shall be determined using the longest length of piping from the point of delivery to the most remote outlet and the load of the section (see Appendix A).

402.4.2 Branch Length Method

Deleted.

402.4.3 Hybrid Pressure

The pipe size for each section of higher pressure gas piping shall be determined using the longest length of piping from the point of delivery to the most remote line pressure regulator. The pipe size from the line pressure regulator to each outlet shall be determined using the length of piping from the regulator to the most remote outlet served by the regulator (see Appendix A).

402.5 Noncorrugated Stainless Steel Tubing

Noncorrugated stainless steel tubing shall be sized in accordance with Equations 4-1 and 4-2 of Section 402.4 in conjunction with Section 402.4.1 or 402.4.3.

402.6 Allowable Pressure Drop

The design pressure loss in any piping system under maximum probable flow conditions, from the point of delivery to the inlet connection of the appliance, shall be such that the supply pressure at the appliance is greater than the minimum pressure required for proper appliance operation.

402.7 Maximum Design Operating Pressure

The maximum design operating pressure for piping systems located inside buildings shall not exceed 5 pounds per square inch gauge (psig) (34 kPa gauge) except where one or more of the following conditions are met:
  1. The piping joints are welded or brazed.
  2. The piping joints are flanged, and pipe-to-flange connections are made by welding or brazing.
  3. The piping is located in a ventilated chase or otherwise enclosed for protection against accidental gas accumulation.
  4. The piping is located inside buildings or separate areas of buildings used exclusively for:
    4.1.  Industrial processing or heating;
    4.2.  Research;
    4.3.  Warehousing; or
    4.4.  Boiler or mechanical rooms.
  5. The piping is a temporary installation for buildings under construction.
  6. The piping serves appliances or equipment used for agricultural purposes.

402.7.1 Liquefied Petroleum Gas Systems

Deleted.

Section 403 Piping Materials

403.1 General

Materials used for piping systems shall comply with the requirements of this chapter or shall be approved.

403.2 Used Materials

Pipe, fittings, valves and other materials shall not be used again except where they are free of foreign materials and have been ascertained to be adequate for the service intended.

403.3 Other Materials

Material not covered by the standards specifications listed herein shall be investigated and tested to determine that it is safe and suitable for the proposed service, and, in addition, shall be recommended for that service by the manufacturer and shall be approved by the code official.

403.4 Metallic Pipe

Metallic pipe shall comply with Sections 403.4.1 through 403.4.4.

403.4.1 Cast Iron

Cast-iron pipe shall not be used.

403.4.2 Steel

Steel, stainless steel and wrought-iron pipe shall be not lighter than Schedule 10 and shall comply with the dimensional standards of ASME B36.10M and one of the following standards:
  1. ASTM A53/A53 M
  2. ASTM A106
  3. ASTM A312

403.4.3 Copper and Brass

Copper and brass pipe shall not be used if the gas contains more than an average of 0.3 grains of hydrogen sulfide per 100 standard cubic feet of gas (0.7 milligrams per 100 liters). Threaded copper, brass and aluminum-alloy pipe shall not be used with gases corrosive to such materials.

403.4.4 Aluminum

Aluminum-alloy pipe shall comply with ASTM B241 except that the use of alloy 5456 is prohibited. Aluminum-alloy pipe and shall be marked at each end of each length indicating compliance. Aluminumalloy pipe shall be coated to protect against external corrosion where it is in contact with masonry, plaster or insulation, or is subject to repeated wettings by such liquids as water, detergents or sewage. Aluminum-alloy pipe shall not be used in exterior locations or underground.

403.5 Metallic Tubing

Seamless copper, aluminum alloy and steel tubing shall not be used with gases corrosive to such materials. Permission to use aluminum or aluminum alloy pipe or fittings or copper pipe, copper tubing or copper fittings for natural gas distribution piping shall be approved by the gas sup- plier prior to the installation of the piping or fittings.

403.5.1 Steel Tubing

Steel tubing shall comply with ASTM A254 or ASTM A539.

403.5.2 Stainless Steel

Stainless steel tubing shall comply with ASTM A268 or ASTM A269.

403.5.3 Copper and Copper Alloy Tubing

Copper tubing shall comply with Standard Type K or L of ASTM B88 or ASTM B280. Copper and copper alloy tubing shall not be used if the gas contains more than an average of 0.3 grain of hydrogen sulfide per 100 standard cubic feet of gas (0.7 milligram per 100 liters).

403.5.4 Aluminum Tubing

Aluminum-alloy tubing shall comply with ASTM B210 or ASTM B241. Aluminumalloy tubing shall be coated to protect against external corrosion where it is in contact with masonry, plaster or insulation, or is subject to repeated wettings by such liquids as water, detergent or sewage. Aluminum-alloy tubing shall not be used in exterior locations or underground.

403.5.5 Corrugated Stainless Steel Tubing

Corrugated stainless steel tubing shall be listed in accordance with ANSI LC 1/CSA 6.26.

403.6 Plastic Pipe, Tubing and Fittings

Plastic pipe, tubing and fittings used to supply fuel gas shall be used outdoors, underground, only, and shall conform to ASTM D2513. Pipe shall be marked "Gas" and "ASTM D2513."
Polyamide pipe, tubing and fittings shall be identified and conform to ASTM F2945. Such pipe shall be marked "Gas" and "ASTM F2945."
Polyvinyl chloride (PVC) and chlorinated polyvinyl chloride (CPVC) plastic pipe, tubing and fittings shall not be used to supply fuel gas.

403.6.1 Anodeless Risers

Plastic pipe, tubing and anodeless risers shall comply with the following:
  1. Factory-assembled anodeless risers shall be recommended by the manufacturer for the gas used and shall be leak tested by the manufacturer in accordance with written procedures.
  2. Service head adapters and field-assembled anodeless risers incorporating service head adapters shall be recommended by the manufacturer for the gas used, and shall be designed and certified to meet the requirements of Category I of ASTM D2513, and US Department of Transportation, Code of Federal Regulations, Title 49, Part 192.281(e). The manufacturer shall provide the user with qualified installation instructions as prescribed by the US Department of Transportation, Code of Federal Regulations, Title 49, Part 192.283(b).

403.6.2 LP-Gas Systems

Deleted.

403.6.3 Regulator Vent Piping

Plastic pipe, tubing and fittings used to connect regulator vents to remote vent terminations shall be PVC conforming to UL 651. PVC vent piping shall not be installed indoors.

403.7 Workmanship and Defects

Pipe, tubing and fittings shall be clear and free from cutting burrs and defects in structure or threading, and shall be thoroughly brushed, and chip and scale blown.
Defects in pipe, tubing and fittings shall not be repaired. Defective pipe, tubing and fittings shall be replaced.

403.8 Protective Coating

Where in contact with material or atmosphere exerting a corrosive action, metallic piping and fittings coated with a corrosion-resistant material shall be used. External or internal coatings or linings used on piping or components shall not be considered as adding strength.

403.9 Metallic Pipe Threads

Metallic pipe and fitting threads Shall be taper pipe threads and shall comply with ASME B1.20.1.

403.9.1 Damaged Threads

Pipe with threads that are stripped, chipped, corroded or otherwise damaged shall not be used. Where a weld opens during the operation of cutting or threading, that portion of the pipe shall not be used.

403.9.2 Number of Threads

Field threading of metallic pipe shall be in accordance with Table 403.9.2.
TABLE 403.9.2
SPECIFICATIONS FOR THREADING METALLIC PIPE
IRON PIPE SIZE
(inches)
 APPROXIMATE LENGTH OF
THREADED PORTION
(inches)		 APPROXIMATE
NUMBER OF THREADS
TO BE CUT
1/2 3/4 10
3/4 3/4 10
1 7/8 10
11/4 1 11
11/2 1 11
2 1 11
21/2 11/2 12
3 11/2 12
4 15/8 13
For SI: 1 inch = 25.4 mm.

403.9.3 Thread Joint Compounds

Thread joint compounds shall be resistant to the action of liquefied petroleum gas or to any other chemical constituents of the gases to be conducted through the piping.

403.10 Metallic Piping Joints and Fittings

The type of piping joint used shall be suitable for the pressure-temperature conditions and shall be selected giving consideration to joint tightness and mechanical strength under the service conditions. The joint shall be able to sustain the maximum end force caused by the internal pressure and any additional forces caused by temperature expansion or contraction, vibration, fatigue or the weight of the pipe and its contents.

403.10.1 Pipe Joints

Schedule 40 and heavier pipe joints shall be threaded, flanged, brazed, welded or assembled with press-connect fittings listed in accordance with ANSI LC4/CSA 6.32. Pipe lighter than Schedule 40 shall be connected using press-connect fittings, threaded, flanged, brazed or welded. Where nonferrous pipe is brazed, the brazing materials shall have a melting point in excess of 1,000°F (538°C). Brazing alloys shall not contain more than 0.05-percent phosphorus.

403.10.2 Copper Tubing Joints

Copper tubing joints shall be assembled with approved gas tubing fittings, shall be brazed with a material having a melting point in excess of 1,000°F (538°C) or assembled with press-connect fittings listed in accordance with ANSI LC-4/CSA 6.32. Brazing alloys shall not contain more than 0.05-percent phosphorus.

403.10.3 Stainless Steel Tubing Joints

Stainless steel tubing joints shall be welded, assembled with approved tubing fittings, brazed with a material having a melting point in excess of 1,000°F (578°C), or assembled with pressconnect fittings listed in accordance with ANSI LC4/CSA 6.32.

403.10.4 Flared Joints

Flared joints shall be used only in systems constructed from nonferrous pipe and tubing where experience or tests have demonstrated that the joint is suitable for the conditions and where provisions are made in the design to prevent separation of the joints.

403.10.5 Metallic Fittings

Metallic fittings shall comply with the following:
  1. Threaded fittings in sizes larger than 4 inches (102 mm) shall not be used except where approved.
  2. Fittings used with steel or wrought-iron pipe shall be steel, copper alloy malleable iron or cast iron.
  3. Fittings used with copper or copper alloy pipe shall be copper, copper alloy.
  4. Fittings used with aluminum-alloy pipe shall be of aluminum alloy.
  5. Cast-iron fittings:
    5.1.  Flanges shall be permitted.
    5.2.  Bushings shall not be used.
    5.3.  Fittings shall not be used in systems containing flammable gas-air mixtures.
    5.4.  Fittings in sizes 4 inches (102 mm) and larger shall not be used indoors except where approved.
    5.5.  Fittings in sizes 6 inches (152 mm) and larger shall not be used except where approved.
  6. Aluminum-alloy fittings. Threads shall not form the joint seal.
  7. Zinc aluminum-alloy fittings. Fittings shall not be used in systems containing flammable gas-air mixtures.
  8. Special fittings. Fittings such as couplings, proprietary-type joints, saddle tees, gland-type compression fittings and flared, flareless and compressiontype tubing fittings shall be: used within the fitting manufacturer's pressure-temperature recommendations; used within the service conditions anticipated with respect to vibration, fatigue, thermal expansion or contraction; installed or braced to prevent separation of the joint by gas pressure or external physical damage; and shall be approved.
  9. Where pipe fittings are drilled and tapped in the field, the operation shall be in accordance with all of the following:
    9.1.  The operation shall be performed on systems having operating pressures of 5 psi (34.5 kPa) or less.
    9.2.  The operation shall be performed by the gas supplier or the gas supplier's designated representative.
    9.3.  The drilling and tapping operation shall be performed in accordance with written procedures prepared by the gas supplier.
    9.4.  The fittings shall be located outdoors.
    9.5.  The tapped fitting assembly shall be inspected and proven to be free of leakage.

403.11 Plastic Pipe, Joints and Fittings

Plastic pipe, tubing and fittings shall be joined in accordance with the manufacturer's instructions. Such joint shall comply with the following:
  1. The joint shall be designed and installed so that the longitudinal pull-out resistance of the joint will be at least equal to the tensile strength of the plastic piping material.
  2. Heat-fusion joints shall be made in accordance with qualified procedures that have been established and proven by test to produce gas-tight joints at least as strong as the pipe or tubing being joined. Joints shall be made with the joining method recommended by the pipe manufacturer. Heat fusion fittings shall be marked "ASTM D2513.
  3. Where compression-type mechanical joints are used, the gasket material in the fitting shall be compatible with the plastic piping and with the gas distributed by the system. An internal tubular rigid stiffener shall be used in conjunction with the fitting. The stiffener shall be flush with the end of the pipe or tubing and shall extend at least to the outside end of the compression fitting when installed. The stiffener shall be free of rough or sharp edges and shall not be a force fit in the plastic. Split tubular stiffeners shall not be used.

403.12 Flanges

Flanges and flange gaskets shall comply with Sections 403.12.1 through 403.12.7.

403.12.1 Cast Iron

Cast-iron flanges shall be in accordance with ASME B16.1.

403.12.2 Steel

Steel flanges shall be in accordance with ASME B16.5 or ASME B16.47.

403.12.3 Nonferrous

Nonferrous flanges shall be in accordance with ASME B16.24.

403.12.4 Ductile Iron

Ductile-iron flanges shall be in accordance with ASME B16.42.

403.12.5 Raised Face

Raised face flanges shall not be joined to flat faced cast-iron, ductile-iron or nonferrous material flanges.

403.12.6 Flange Facings

Standard facings shall be permitted for use under this code. Where 150-pound (1034 kPa) pressure-rated steel flanges are bolted to Class 125 cast-iron flanges, the raised face on the steel flange shall be removed.

403.12.7 Lapped Flanges

Lapped flanges shall be used only above ground or in exposed locations accessible for inspection.

403.13 Flange Gaskets

Material for gaskets shall be capable of withstanding the design temperature and pressure of the piping system, and the chemical constituents of the gas being conducted, without change to its chemical and physical properties. The effects of fire exposure to the joint shall be considered in choosing material. Acceptable materials include metal (plain or corrugated), composition aluminum "O" rings, spiral wound metal gaskets, rubber-faced phenolic and elastomeric. When a flanged joint is opened, the gasket shall be replaced. Full-face gaskets shall be used with all non-steel flanges.

403.13.1 Metallic Gaskets

Metallic flange gaskets shall be in accordance with ASME B16.20.

403.13.2 Nonmetallic Gaskets

Nonmetallic flange gaskets shall be in accordance with ASME B16.21.

Section 404 Piping System Installation

404.1 Installation of Materials

Materials used shall be installed in strict accordance with the standards under which the materials are accepted and approved. In the absence of such installation procedures, the manufacturer's instructions shall be followed. Where the requirements of referenced standards or manufacturer's instructions do not conform to minimum provisions of this code, the provisions of this code shall apply.

404.2 CSST

CSST piping systems shall be installed in accordance with the terms of their approval, the conditions of listing, the manufacturer's instructions and this code.

404.3 Prohibited Locations

Piping shall not be installed in or through a ducted supply, return or exhaust, or a clothes chute, chimney or gas vent, dumbwaiter or elevator shaft. Piping installed downstream of the point of delivery shall not extend through any townhouse unit other than the unit served by such piping. Piping shall be located to minimize the likelihood of damage by moving vehicles unless protected by a barrier of sufficient size and strength to protect such piping.

404.4 Piping in Solid Partitions and Walls

Concealed piping shall not be located in solid partitions and solid walls, unless installed in a chase or casing.

404.5 Piping in Concealed Locations

Fittings installed in concealed locations shall be limited to the following types:
  1. Threaded elbows, tees and couplings.
  2. Brazed fittings.
  3. Welded fittings.
  4. Fittings listed to ANSI LC-1/CSA 6.26 or ANSI LC-4/CSA 6.32.

404.6 Underground Penetrations Prohibited

Gas piping shall not penetrate building foundation walls at any point below grade. Gas piping shall enter and exit a building at a point above grade and the annular space between the pipe and the wall shall be sealed.

404.7 Protection Against Physical Damage

Where piping will be concealed within light-frame construction assemblies, the piping shall be protected against penetration by fasteners in accordance with Sections 404.7.1 through 404.7.3.
Exception: Black steel piping and galvanized steel piping shall not be required to be protected.

404.7.1 Piping Through Holes or Notches

Where piping is installed through holes or notches in framing members and the piping is located less than 11/2 inches (38 mm) from the framing member face to which wall, ceiling or floor membranes will be attached, the pipe shall be protected by shield plates that cover the width of the pipe and the framing member and that extend not less than 4 inches (102 mm) to each side of the framing member. Where the framing member that the piping passes through is a bottom plate, bottom track, top plate or top track, the shield plates shall cover the framing member and extend not less than 4 inches (102 mm) above the bottom framing member and not less than 4 inches (102 mm) below the top framing member.

404.7.2 Piping Installed in Other Locations

Where the piping is located within a framing member and is less than 11/2 inches (38 mm) from the framing member face to which wall, ceiling or floor membranes will be attached, the piping shall be protected by shield plates that cover the width and length of the piping. Where the piping is located outside of a framing member and is located less than 11/2 inches (38 mm) from the nearest edge of the face of the framing member to which the membrane will be attached, the piping shall be protected by shield plates that cover the width and length of the piping.

404.7.3 Shield Plates

Shield plates shall be of steel material having a thickness of not less than 0.0575 inch (1.463 mm) (No. 16 gage).

404.8 Piping in Solid Floors

Piping in solid floors shall be laid in channels in the floor and covered in a manner that will allow access to the piping with a minimum amount of damage to the building. Where such piping is subject to exposure to excessive moisture or corrosive substances, the piping shall be protected in an approved manner. As an alternative to installation in channels, the piping shall be installed in a conduit of Schedule 40 steel, wrought iron, PVC or ABS pipe in accordance with Section 404.8.1 or 404.8.2 with tightly sealed ends and joints. Both ends of such conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor. The conduit shall be vented above grade to the outdoors and shall be installed so as to prevent the entry of water and insects.

404.8.1 Conduit With One End Terminating Outdoors

The conduit shall extend into an occupiable portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the possible entrance of any gas leakage. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor. If the end sealing is capable of withstanding the full pressure of the gas pipe, the conduit shall be designed for the same pressure as the pipe. Such conduit shall extend not less than 4 inches (102 mm) outside the building, shall be vented above grade to the outdoors and shall be installed so as to prevent the entrance of water and insects.

404.8.2 Conduit With Both Ends Terminating Indoors

Where the conduit originates and terminates within the same building, the conduit shall originate and terminate in an accessible portion of the building and shall not be sealed. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor.

404.9 Above-Ground Outdoor Piping

All piping installed outdoors shall be elevated not less than 31/2 inches (89 mm) above ground and where installed across roof surfaces, shall be elevated not less than 31/2 inches (89 mm) above the roof surface. Piping installed above ground, outdoors, and installed across the surface of roofs shall be securely supported and located where it will be protected from physical damage. Where passing through an outside wall, the piping shall also be protected against corrosion by coating or wrapping with an inert material. Where piping is encased in a protective pipe sleeve, the annular space between the piping and the sleeve shall be sealed.

404.10 Isolation

Deleted.

404.11 Protection Against Corrosion

Steel piping or tubing exposed to corrosive action, such as soil condition or moisture, shall be protected in accordance with Sections 404.11.1 through 404.11.5.

404.11.1 Galvanizing

Zinc coatings shall not be deemed adequate protection for underground gas piping.

404.11.2 Protection Methods

Underground piping shall comply with one or more of the following:
  1. The piping shall be made of corrosion-resistant material that is suitable for the environment in which it will be installed.
  2. Pipe shall have a factory-applied, electrically-insulating coating. Fittings and joints between sections of coated pipe shall be coated in accordance with the coating manufacturer's instructions.
  3. The piping shall have a cathodic protection system installed and the system shall be monitored and maintained in accordance with an approved program.

404.11.3 Dissimilar Metals

Where dissimilar metals are joined underground, an insulating coupling or fitting shall be used.

404.11.4 Protection of Risers

Steel risers connected to plastic piping shall be cathodically protected by means of a welded anode, except where such risers are anodeless risers.

404.11.5 Prohibited Use

Uncoated threaded or socket welded joints shall not be used in piping in contact with soil or where internal or external crevice corrosion is known to occur.

404.12 Minimum Burial Depth

Underground piping systems shall be installed a minimum depth of 12 inches (305 mm) below grade, except as provided for in Section 404.12.1. The laying or installing of gas piping in the same ditch with water, sewer, or drainage pipe is prohibited except when approved by state administrative authority. Underground gas piping shall not be placed closer than 8 inches (203 mm) from a water or sewer pipe.

404.12.1 Individual Outdoor Appliances

Individual lines to outside lights, grills or other appliances shall be installed a minimum of 8 inches (203 mm) below finished grade, provided that such installation is approved and is installed in locations not susceptible to physical damage.

404.13 Trenches

The trench shall be graded so that the pipe has a firm, substantially continuous bearing on the bottom of the trench.

404.14 Piping Underground Beneath Buildings

Piping installed underground beneath buildings is prohibited except where the piping is encased in a conduit of wrought iron, plastic pipe, steel pipe, a piping or encasement system listed for installation beneath buildings, or other approved conduit material designed to withstand the superimposed loads. Such conduit shall extend into an occupiable portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the possible entrance of any gas leakage. The conduit shall be protected from corrosion in accordance with Section 404.11 and shall be installed in accordance with Section 404.14.1 or 404.14.2.

404.14.1 Conduit With One End Terminating Outdoors

The conduit shall extend into an occupiable portion of the building and, at the point where the conduit terminates in the building, the space between the conduit and the gas piping shall be sealed to prevent the possible entrance of any gas leakage. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor. Where the end sealing is capable of withstanding the full pressure of the gas pipe, the conduit shall be designed for the same pressure as the pipe. Such conduit shall extend not less than 4 inches (102 mm) outside of the building, shall be vented above grade to the outdoors and shall be installed so as to prevent the entrance of water and insects.

404.14.2 Conduit With Both Ends Terminating Indoors

Where the conduit originates and terminates within the same building, the conduit shall originate and terminate in an accessible portion of the building and shall not be sealed. The conduit shall extend not less than 2 inches (51 mm) beyond the point where the pipe emerges from the floor.

404.15 Outlet Closures

Gas outlets that do not connect to appliances shall be capped gas tight.
Exception: Listed and labeled flush-mounted-type quickdisconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer's installation instructions.

404.16 Location of Outlets

The unthreaded portion of piping outlets shall extend not less than l inch (25 mm) through finished ceilings and walls and where extending through floors or outdoor patios and slabs, shall not be less than 2 inches (51 mm) above them. The outlet fitting or piping shall be securely supported. Outlets shall not be placed behind doors. Outlets shall be located in the room or space where the appliance is installed.
Exception: Listed and labeled flush-mounted-type quickdisconnect devices and listed and labeled gas convenience outlets shall be installed in accordance with the manufacturer's installation instructions.

404.17 Plastic Pipe

The installation of plastic pipe shall comply with Sections 404.14.1 through 404.14.3.

404.17.1 Limitations

Plastic pipe shall be installed outside underground only. Plastic pipe shall not be used within or under any building or slab or be operated at pressures greater than 100 psig (689 kPa) for natural gas.
Exceptions:
  1. Plastic pipe shall be permitted to terminate above ground outside of buildings where installed in premanufactured anodeless risers or service head adapter risers that are installed in accordance with the manufacturer's instructions.
  2. Plastic pipe shall be permitted to terminate with a wall head adapter within buildings where the plastic pipe is inserted in a piping material for fuel gas use in buildings.
  3. Plastic pipe shall be permitted under outdoor patio, walkway and driveway slabs provided that the burial depth complies with Section 404.12.

404.17.2 Connections

Connections made outside and underground between metallic and plastic piping shall be made only with transition fittings conforming to ASTM D2513 Category I or ASTM F1973 categorized as Category I in accordance with ASTM D2513.

404.18 Pipe Cleaning

The use of a flammable or combustible gas to clean or remove debris from a piping system shall be prohibited.

404.19 Prohibited Devices

A device shall not be placed inside the piping or fittings that will reduce the cross-sectional area or otherwise obstruct the free flow of gas.
Exceptions:
  1. Approved gas filters.
  2. An approved fitting or device where the gas piping system has been sized to accommodate the pressure drop of the fitting or device.

404.20 Testing of Piping

Before any system of piping is put in service or concealed, it shall be tested to ensure that it is gas tight. Testing, inspection and purging of piping systems shall comply with Section 406.

Section 405 Piping Bends and Changes in Direction

405.1 General

Changes in direction of pipe shall be permitted to be made by the use of fittings, factory bends, or field bends.

405.2 Metallic Pipe

Metallic pipe bends shall comply with the following:
  1. Bends shall be made only with bending tools and procedures intended for that purpose.
  2. All bends shall be smooth and free from buckling, cracks or other evidence of mechanical damage.
  3. The longitudinal weld of the pipe shall be near the neutral axis of the bend.
  4. Pipe shall not be bent through an arc of more than 90 degrees (1.6 rad).
  5. The inside radius of a bend shall be not less than six times the outside diameter of the pipe.

405.3 Plastic Pipe

Plastic pipe bends shall comply with the following:
  1. The pipe shall not be damaged, and the internal diameter of the pipe shall not be effectively reduced.
  2. Joints shall not be located in pipe bends.
  3. The radius of the inner curve of such bends shall not be less than 25 times the inside diameter of the pipe.
  4. Where the piping manufacturer specifies the use of special bending tools or procedures, such tools or procedures shall be used.

405.4 Elbows

Factory-made welding elbows or transverse segments cut therefrom shall have an arc length measured along the crotch at least 1 inch (25 mm) in pipe sizes 2 inches (51 mm) and larger.

Section 406 Inspection, Testing and Purging

406.1 General

Prior to acceptance and initial operation, all piping installations shall be inspected, and pressure tested to determine that the materials, design, fabrication, and installation practices comply with the requirements of this code.

406.1.1 Inspections

Inspection shall consist of visual examination, during or after manufacture, fabrication, assembly, or pressure tests.

406.1.2 Repairs and Additions

In the event repairs or additions are made after the pressure test, the affected piping shall be tested. Minor repairs and additions are not required to be pressure tested provided that the work is inspected, and connections are tested with a noncorrosive leak-detecting fluid or other approved leak-detecting methods.

406.1.3 New Branches

Where new branches are installed to new appliances, only the newly installed branches shall be required to be pressure tested. Connections between the new piping and the existing piping shall be tested with a noncorrosive leak-detecting fluid or other approved leakdetecting methods.

406.1.4 Section Testing

A piping system shall be permitted to be tested as a complete unit or in sections. A valve in a line be used as a bulkhead between gas in one section of the piping system and test medium in an adjacent section, except where a double block and bleed valve system is installed A valve shall not be subjected to the test pressure unless it can be determined that the valve, including the valve-closing mechanism, is designed to safely withstand the test pressure.

406.1.5 Regulators and Valve Assemblies

Regulator and valve assemblies fabricated independently of the piping system in which they are to be installed shall be permitted to be tested with inert gas or air at the time of fabrication.

406.1.6 Pipe Clearing

Prior to testing, the interior of the pipe shall be cleared of all foreign material.

406.2 Test Medium

The test medium shall be air, nitrogen, carbon dioxide or an inert gas. Oxygen shall not be used as a test medium.

406.3 Test Preparation

Pipe joints, including welds, shall be left exposed for examination during the test.
Exception: Covered or concealed pipe end joints that have been previously tested in accordance with this code.

406.3.1 Expansion Joints

Expansion joints shall be provided with temporary restraints, if required, for the additional thrust load under test.

406.3.2 Appliance and Equipment Isolation

Appliances and equipment that are not to be included in the test shall be either disconnected from the piping or isolated by blanks, blind flanges, or caps. Flanged joints at which blinds are inserted to blank off other equipment during the test shall not be required to be tested.

406.3.3 Appliance and Equipment Disconnection

Where the piping system is connected to appliances or equipment designed for operating pressures of less than the test pressure, such appliances or equipment shall be isolated from the piping system by disconnecting them and capping the outlet(s).

406.3.4 Valve Isolation

Where the piping system is connected to appliances or equipment designed for operating pressures equal to or greater than the test pressure, such appliances or equipment shall be isolated from the piping system by closing the individual appliance or equipment shutoff valve(s).

406.3.5 Testing Precautions

Testing of piping systems shall be performed in a manner that protects the safety of employees and the public during the test, with due regard for the safety of employees and the public during the test.

406.4 Test Pressure Measurement

Test pressure shall be measured with a manometer or with a pressure-measuring device designed and calibrated to read, record or indicate a pressure loss caused by leakage during the pressure test period. The source of pressure shall be isolated before the pressure tests are made. Mechanical gauges used to measure test pressures shall have a range such that the highest end of the scale is not greater than five times the test pressure.

406.4.1 Test Pressure

Each segment of consumer piping shall be tested at not less than 11/2 times the proposed maximum working pressure, but not less than 3 psig (34 kPa gauge), irrespective of design pressure.

406.4.2 Test Duration

Test duration shall be not less than 1/2 hour for each 500 cubic feet (14 m3) of pipe volume. When testing a system having a volume 250 cubic feet (7 m3) or less or a system in a single-family dwelling, the test duration shall be not less than 15 minutes.

406.5 Detection of Leaks and Defects

The piping system shall withstand the test pressure specified without showing any evidence of leakage or other defects. Any reduction of test pressures as indicated by pressure gauges shall be deemed to indicate the presence of a leak unless such reduction can be readily attributed to some other cause.

406.5.1 Detection Methods

The leakage shall be located by means of an approved gas detector, a noncorrosive leak detection fluid, or other approved leak detection methods.

406.5.2 Corrections

Where leakage or other defects are located, the affected portion of the piping system shall be repaired or replaced and retested.

406.6 Piping System and Equipment Leakage Check

Leakage checking of systems and equipment shall be in accordance with Sections 406.6.1 through 406.6.4.

406.6.1 Test Gases

Leak checks using fuel gas shall be permitted in piping systems that have been pressure tested in accordance with Section 406.

406.6.2 Before Turning Gas On

During the process of turning gas on into a system of new gas piping, the entire system shall be inspected to determine that there are no open fittings or ends and that all valves at unused outlets are closed and plugged or capped.

406.6.3 Leak Check

Immediately after the gas is turned on into a new system or into a system that has been initially restored after an interruption of service, the piping system shall be checked for leakage. Where leakage is indicated, the gas supply shall be shut off until the necessary repairs have been made.

406.6.4 Placing Appliances and Equipment in Operation

Appliances and equipment shall not be placed in operation until after the piping system has been checked for leakage in accordance with Section 406.6.3, the piping system has been purged in accordance with Section 406.7.2, and the connection to the appliance has been checked for leakage.

406.7 Purging

Purging of piping shall comply with Sections 406.7.1 and 406.7.3.

406.7.1 Piping Systems Required to Be Purged Outdoors

The purging of piping systems shall be in accordance with the provisions of Sections 406.7.1.1 through 406.7.1.4 where the piping system meets either of the following:
  1. The design operating gas pressure is greater than 2 psig (13.79 kPa).
  2. The piping being purged contains one or more sections of pipe or tubing meeting the size and length criteria of Table 406.7.1.1.

406.7.1.1 Removal From Service

Where gas piping is opened, the section that is opened shall be isolated from the gas supply and the line pressure vented in accordance with Section 406.7.1.3. Where gas piping meeting the criteria of Table 406.7.1.1 is removed from service, the residual fuel gas in the piping shall be displaced with an inert gas.
TABLE 406.7.1.1
SIZE AND LENGTH OF PIPING INERT GAS FOR SERVICING OR MODIFICATION
NOMINAL PIPE SIZE
(inches)a
LENGTH OF PIPING
REQUIRING PURGING
≥ 21/2 < 3 > 50 feet
≥ 3 < 4 > 30 feet
≥ 4 < 6 > 15 feet
≥ 6 < 8 > 10 feet
≥ 8 or larger Any length
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm.
  1. CSST EHD size of 62 is equivalent to nominal 2-inch pipe or tubing size.

406.7.1.2 Placing in Operation

Where gas piping containing air and meeting the criteria of Table 406.7.1.1 is placed in operation, the air in the piping shall be displaced with an inert gas. The inert gas shall then be displaced with fuel gas in accordance with Section 406.7.1.3.

406.7.1.3 Outdoor Discharge of Purged Gases

The open end of a piping system being pressure vented or purged shall discharge directly to an outdoor location. Purging operations shall comply with all of the following requirements:
  1. The point of discharge shall be controlled with a shutoff valve.
  2. The point of discharge shall be located not less than 10 feet (3048 mm) from sources of ignition, not less than 10 feet (3048 mm) from building openings and not less than 25 feet (7620 mm) from mechanical air intake openings.
  3. During discharge, the open point of discharge shall be continuously attended and monitored with a combustible gas indicator that complies with Section 406.7.1.4.
  4. Purging operations introducing fuel gas shall be stopped when 90 percent fuel gas by volume is detected within the pipe.
  5. Persons not involved in the purging operations shall be evacuated from all areas within 10 feet (3048 mm) of the point of discharge.

406.7.1.4 Combustible Gas Indicator

Combustible gas indicators shall be listed and shall be calibrated in accordance with the manufacturer's instructions. Combustible gas indicators shall numerically display a volume scale from zero percent to 100 percent in 1-percent or smaller increments.

406.7.2 Piping Systems Allowed to Be Purged Indoors or Outdoors

The purging of piping systems shall be in accordance with the provisions of Section 406.7.2.1 where the piping system meets both of the following:
  1. The design operating gas pressure is 2 psig (13.79 kPa) or less.
  2. The piping being purged is constructed entirely from pipe or tubing not meeting the size and length criteria of Table 406.7.1.1.

406.7.2.1 Purging Procedure

The piping system shall be purged in accordance with one or more of the following:
  1. The piping shall be purged with fuel gas and shall discharge to the outdoors.
  2. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through an appliance burner not located in a combustion chamber. Such burner shall be provided with a continuous source of ignition.
  3. The piping shall be purged with fuel gas and shall discharge to the indoors or outdoors through a burner that has a continuous source of ignition and that is designed for such purpose.
  4. The piping shall be purged with fuel gas that is discharged to the indoors or outdoors, and the point of discharge shall be monitored with a listed combustible gas detector in accordance with Section 406.7.2.2. Purging shall be stopped when fuel gas is detected.
  5. The piping shall be purged by the gas supplier in accordance with written procedures.

406.7.2.2 Combustible Gas Detector

Combustible gas detectors shall be listed and shall be calibrated or tested in accordance with the manufacturer's instructions. Combustible gas detectors shall be capable of indicating the presence of fuel gas.

406.7.3 Purging Appliances and Equipment

After the piping system has been placed in operation, all appliances and equipment shall be purged before being placed into operation and then placed in operation, as necessary.

Section 407 Piping Support

407.1 General

Piping shall be provided with support in accordance with Section 407.2.

407.2 Design and Installation

Piping shall be supported with metal pipe hooks, metal pipe straps, metal bands, metal brackets, metal hangers or building structural components suitable for the size of piping, of adequate strength and quality, and located at intervals so as to prevent or damp out excessive vibration. Piping shall be anchored to prevent undue strains on connected appliances and shall not be supported by other piping. Pipe hangers and supports shall conform to the requirements of MSS SP-58 and shall be spaced in accordance with Section 415. Supports, hangers, and anchors shall be installed so as not to interfere with the free expansion and contraction of the piping between anchors. The components of the supporting equipment shall be designed and installed so they will not be disengaged by movement of the supported piping.

407.2.1 Seismic Supports

Where earthquake loads are applicable according to this code, the Arkansas Fire Prevention Code and Arkansas Mechanical Code, gas appliances, piping and duct supports shall be designed and installed for the seismic forces in the Arkansas Fire Prevention Code and the National Electrical Code.

Section 408 Drips and Sloped Piping

408.1 Slopes

Piping for other than dry gas conditions shall be sloped not less than 1/4 inch in 15 feet (6.3 mm in 4572 mm) to prevent traps.

408.2 Drips

Where wet gas exists, a drip shall be provided at any point in the line of pipe where condensate could collect. A drip shall also be provided at the outlet of the meter and shall be installed so as to constitute a trap wherein an accumulation of condensate will shut off the flow of gas before the condensate will run back into the meter.

408.3 Location of Drips

Drips shall be provided with ready access to permit cleaning or emptying. A drip shall not be located where the condensate is subject to freezing.

408.4 Sediment Trap

Where a sediment trap is not incorporated as part of the appliance, a sediment trap shall be installed downstream of the appliance shutoff valve as close to the inlet of the appliance as practical. The sediment trap shall be either a tee fitting with a capped nipple in the bottom most opening of the tee or other device approved as an effective sediment trap. Illuminating appliances, ranges, clothes dryers and outdoor grills need not be so equipped.

Section 409 Shutoff Valves

409.1 General

Piping systems shall be provided with shutoff valves in accordance with this section.

409.1.1 Valve Approval

Shutoff valves shall be of an approved type; shall be constructed of materials compatible with the piping; and shall comply with the standard that is applicable for the pressure and application, in accordance with Table 409.1.1.
TABLE 409.1.1
MANUAL GAS VALVE STANDARDS
VALVE STANDARDS APPLIANCE SHUTOFF
VALVE APPLICATION UP
TO 1/2 psig PRESSURE		 OTHER VALVE APPLICATIONS
UP TO 1/2 psig
PRESSURE
 UP TO 2 psig
PRESSURE
 UP TO 5 psig
PRESSURE
 UP TO 125 psig
PRESSURE
ANSI Z21.15 X — — — —
CSA Requirement 3-88 X X Xa Xb —
ASME B16.44 X X Xa Xb —
ASME B16.33 X X X X X
For SI: 1 pound per square inch gauge = 6.895 kPa.
  1. If labeled 2G.
  2. If labeled 5G.

409.1.2 Prohibited Locations

Shutoff valves shall be prohibited in concealed locations and furnace plenums.

409.1.3 Access to Shutoff Valves

Shutoff valves shall be located in places so as to provide access for operation and shall be installed so as to be protected from damage.

409.2 Meter Valve

Every meter shall be equipped with a shut-off valve located on the supply side of the meter.

409.3 Shutoff Valves for Multiple-House Line Systems

Where a single meter is used to supply gas to more than one building or tenant, a separate shutoff valve shall be provided for each building or tenant.

409.3.1 Multiple Tenant Buildings

In multiple tenant buildings, where a common piping system is installed to supply other than one- and two-family dwellings, shutoff valves shall be provided for each tenant. Each tenant shall have access to the shutoff valve serving that tenant's space.

409.3.2 Individual Buildings

In a common system serving more than one building, shutoff valves shall be installed outdoors at each building.

409.3.3 Identification of Shutoff Valves

Each house line shutoff valve shall be plainly marked with an identification tag attached by the installer so that the piping systems supplied by such valves are readily identified.

409.4 MP Regulator Valves

A listed shutoff valve shall be installed immediately ahead of each MP regulator.

409.5 Appliance Shutoff Valve

Each appliance shall be provided with a shutoff valve in accordance with Sections 409.5.1, 409.5.2 or 409.5.3 separate from the appliance and shall be installed upstream from the union, valves shall be provided with access.

409.5.1 Located Within Same Room

The shutoff valve shall be located in the same room as the appliances. The shutoff valve shall be within 6 feet (1829 mm) of the appliances, and shall be installed upstream of the union, connector or quick disconnect device it serves. Such shutoff valves shall be provided with access. Shutoff valves serving movable appliances, such as cooking appliances and clothes dryers, shall be considered to be provided with access where installed behind such appliances. Appliance shutoff valves located in the firebox of a fireplace shall be installed in accordance with the appliance manufacturer's instructions.

409.5.2 Vented Decorative Appliances and Room Heaters

Shutoff valves for vented decorative appliances, room heaters and decorative appliances for installation in vented fireplaces shall be permitted to be installed in an area remote from the appliances where such valves are provided with ready access. Such valves shall be permanently identified and shall not serve another appliance. The piping from the shutoff valve to within 6 feet (1829 mm) of the appliance shall be designed, sized and installed in accordance with Sections 401 through 408.

409.5.3 Located at Manifold

Where the appliance shutoff valve is installed at a manifold, such shutoff valve shall be located within 50 feet (15 240 mm) of the appliance served and shall be readily accessible and permanently identified. The piping from the manifold to within 6 feet (1829 mm) of the appliance shall be designed, sized and installed in accordance with Sections 401 through 408.

409.6 Shutoff Valve for Laboratories

Where provided with two or more fuel gas outlets, including table-, bench- and hood-mounted outlets, each laboratory space in educational, research, commercial and industrial