NABIC Discharge Tables

Browse NABIC discharge capacity tables and temperature rating information for Fig. 500, Fig. 542, Fig. 500T and Fig. 500L valves. Select a valve model and an available application to view its discharge capacities by set pressure and valve size, together with the relevant operating conditions and standards.

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Fig 500 — Air

  • 10% overpressure (BS EN 4126-1)
  • Capacity: std. litres/sec · Derated discharge coefficient (Kdr): 0.479
  • First column: set pressure in bar. Size columns: DN15–DN65.
Set Pressure Bar 15 20 25 32 40 50 65
1.00 34 61 95 156 244 381 644
1.25 39 69 108 177 276 431 729
1.50 43 77 120 197 308 481 813
1.75 48 85 133 217 340 531 897
2.00 52 93 145 238 372 581 982
2.25 57 101 158 258 404 631 1066
2.50 61 109 170 279 436 681 1150
2.75 66 117 183 299 468 730 1235
3.00 70 125 195 320 500 780 1319
3.25 75 133 208 340 532 830 1403
3.50 79 141 220 360 564 880 1488
3.75 84 149 233 381 596 930 1572
4.00 88 157 245 401 628 980 1656
4.25 93 165 258 422 659 1030 1741
4.50 97 173 270 442 691 1080 1825
4.75 102 181 283 463 723 1130 1909
5.00 106 189 295 483 755 1180 1994
5.25 111 197 308 504 787 1229 2078
5.50 115 205 320 524 819 1279 2163
5.75 120 213 332 544 851 1329 2247
6.00 124 221 345 565 883 1379 2331
6.25 129 229 357 585 915 1429 2416
6.50 133 237 370 606 947 1479 2500
6.75 138 245 382 626 979 1529 2584
7.00 142 253 395 647 1011 1579 2669
7.25 147 261 407 667 1043 1629 2753
7.50 151 269 420 688 1075 1679 2837
7.75 156 276 432 708 1107 1729 2922
8.00 160 284 445 728 1139 1778 3006
8.25 165 292 457 749 1171 1828 3090
8.50 169 300 470 769 1203 1878 3175
8.75 174 308 482 790 1235 1928 3259
9.00 178 316 495 810 1267 1978 3343
9.25 183 324 507 831 1299 2028 3428
9.50 187 332 520 851 1331 2078 3512
9.75 192 340 532 871 1363 2128 3597
10.00 196 348 545 892 1394 2178 3681
10.25 201 356 557 912 1426 2228 3765
10.50 205 364 570 933 1458 2277 3850
10.75 210 372 582 953 1490 2327 3934
11.00 214 380 595 974 1522 2377 4018
11.25 219 388 607 994 1554 2427 4103
11.50 223 396 620 1015 1586 2477 4187
11.75 228 404 632 1035 1618 2527 4271
12.00 232 412 645 1055 1650 2577 4356
12.25 237 420 657 1076 1682 2627 4440
12.50 241 428 670 1096 1714 2677 4524

To convert to ft³/min multiply by 2.1.

Fig 500 — Steam

  • 10% overpressure (BS 6759)
  • Capacity: kg/hr · Derated discharge coefficient (Kdr): 0.479
  • First column: set pressure in bar. Size columns: DN15–DN65.
Set Pressure Bar 15 20 25 32 40 50 65
1.00 93 166 259 425 664 1037 1752
1.25 106 188 293 480 751 1172 1982
1.50 118 209 327 536 838 1308 2211
1.75 130 231 361 591 925 1444 2441
2.00 142 253 395 647 1012 1580 2670
2.25 155 274 429 703 1098 1715 2900
2.50 167 296 463 758 1185 1851 3129
2.75 179 318 497 814 1272 1987 3358
3.00 191 340 531 869 1359 2123 3588
3.25 204 361 565 925 1446 2258 3817
3.50 216 383 599 981 1533 2394 4047
3.75 228 405 633 1036 1620 2530 4276
4.00 240 426 667 1092 1707 2666 4506
4.25 253 448 701 1147 1794 2801 4735
4.50 265 470 735 1203 1881 2937 4965
4.75 277 492 769 1259 1968 3073 5194
5.00 289 513 803 1314 2055 3209 5424
5.25 302 535 837 1370 2142 3344 5653
5.50 314 557 870 1425 2229 3480 5882
5.75 326 578 904 1481 2315 3616 6112
6.00 338 600 938 1537 2402 3752 6341
6.25 351 622 972 1592 2489 3887 6571
6.50 363 644 1006 1648 2576 4023 6800
6.75 375 665 1040 1703 2663 4159 7030
7.00 387 687 1074 1759 2750 4295 7259
7.25 399 709 1108 1815 2837 4430 7489
7.50 412 730 1142 1870 2924 4566 7718
7.75 424 752 1176 1926 3011 4702 7948
8.00 436 774 1210 1981 3098 4838 8177
8.25 448 796 1244 2037 3185 4973 8407
8.50 461 817 1278 2093 3272 5109 8636
8.75 473 839 1312 2148 3359 5245 8865
9.00 485 861 1346 2204 3446 5381 9095
9.25 497 882 1380 2259 3532 5516 9324
9.50 510 904 1414 2315 3619 5652 9554
9.75 522 926 1448 2371 3706 5788 9783
10.00 534 948 1482 2426 3793 5924 10013
10.25 546 969 1516 2482 3880 6059 10242
10.50 559 991 1550 2537 3967 6195 10472
10.75 571 1013 1584 2593 4054 6331 10701
11.00 583 1034 1618 2649 4141 6467 10931
11.25 595 1056 1651 2704 4228 6603 11160
11.50 608 1078 1685 2760 4315 6738 11389
11.75 620 1100 1719 2815 4402 6874 11619
12.00 632 1121 1753 2871 4489 7010 11848
12.25 644 1143 1787 2927 4576 7146 12078
12.50 657 1165 1821 2982 4663 7281 12307

Fig 500 — Water — Unvented System

  • 10% overpressure (BS EN 4126-1)
  • Capacity: kg/min water · Derated discharge coefficient (Kdr): 0.479
  • First column: set pressure in bar. Size columns: DN15–DN65.
Set Pressure Bar 15 20 25 32 40 50 65
1.00 75 134 209 343 536 837 1414
1.25 84 150 234 383 599 936 1581
1.50 92 164 256 420 656 1025 1732
1.75 100 177 277 453 709 1107 1871
2.00 107 189 296 485 758 1183 2000
2.25 113 201 314 514 804 1255 2122
2.50 119 212 331 542 847 1323 2236
2.75 125 222 347 568 889 1388 2346
3.00 131 232 363 594 928 1449 2450
3.25 136 241 377 618 966 1509 2550
3.50 141 250 392 641 1002 1566 2646
3.75 146 259 405 664 1038 1620 2739
4.00 151 268 419 685 1072 1674 2829
4.25 156 276 432 707 1105 1725 2916
4.50 160 284 444 727 1137 1775 3000
4.75 164 292 456 747 1168 1824 3083
5.00 169 299 468 766 1198 1871 3163
5.25 173 307 480 785 1228 1917 3241
5.50 177 314 491 804 1257 1962 3317
5.75 181 321 502 822 1285 2007 3392
6.00 185 328 513 840 1313 2050 3465
6.25 189 335 523 857 1340 2092 3536
6.50 192 341 534 874 1366 2133 3606
6.75 196 348 544 890 1392 2174 3675
7.00 200 354 554 907 1418 2214 3742
7.25 203 360 564 923 1443 2253 3808
7.50 207 367 573 939 1467 2292 3874
7.75 210 373 583 954 1492 2330 3938
8.00 213 379 592 969 1516 2367 4001
8.25 217 384 601 984 1539 2404 4063
8.50 220 390 610 999 1562 2440 4124
8.75 223 396 619 1014 1585 2475 4184
9.00 226 402 628 1028 1608 2510 4243
9.25 229 407 637 1042 1630 2545 4302
9.50 233 413 645 1056 1652 2579 4360
9.75 236 418 654 1070 1673 2613 4417
10.00 239 423 662 1084 1695 2646 4473
10.25 242 429 670 1097 1716 2679 4528
10.50 244 434 678 1111 1736 2712 4583
10.75 247 439 686 1124 1757 2744 4638
11.00 250 444 694 1137 1777 2775 4691
11.25 253 449 702 1150 1797 2807 4744
11.50 256 454 710 1162 1817 2838 4797
11.75 259 459 717 1175 1837 2868 4848
12.00 261 464 725 1187 1856 2899 4900
12.25 264 468 733 1200 1875 2929 4951
12.50 267 473 740 1212 1895 2959 5001

Discharge capacities calculated in accordance with BS EN 4126-1 & BS 6759, using a derated coefficient of discharge (Kdr) 0.479, approved by AOTC.

Fig 500 — Hot Water — Unvented System

  • 10% overpressure (BS EN 4126-1)
  • Capacity: kW · Derated discharge coefficient (Kdr): 0.479
  • First column: set pressure in bar. Size columns: DN15–DN65.
Set Pressure Bar 15 20 25 32 40 50 65
1.00 59 104 162 266 416 650 1098
1.25 66 118 184 301 470 735 1242
1.50 74 131 205 336 525 820 1386
1.75 82 145 226 371 579 905 1529
2.00 89 158 248 405 634 990 1673
2.25 97 172 269 440 688 1075 1817
2.50 105 186 290 475 743 1160 1961
2.75 112 199 311 510 797 1245 2105
3.00 120 213 333 545 852 1330 2248
3.25 128 226 354 580 906 1415 2392
3.50 135 240 375 615 961 1500 2536
3.75 143 254 397 649 1015 1585 2680
4.00 151 267 418 684 1070 1670 2824
4.25 158 281 439 719 1124 1756 2967
4.50 166 294 460 754 1179 1841 3111
4.75 174 308 482 789 1233 1926 3255
5.00 181 322 503 824 1288 2011 3399
5.25 189 335 524 858 1342 2096 3543
5.50 197 349 546 893 1397 2181 3686
5.75 204 362 567 928 1451 2266 3830
6.00 212 376 588 963 1505 2351 3974
6.25 220 390 609 998 1560 2436 4118
6.50 227 403 631 1033 1614 2521 4262
6.75 235 417 652 1067 1669 2606 4405
7.00 243 431 673 1102 1723 2691 4549
7.25 250 444 694 1137 1778 2776 4693
7.50 258 458 716 1172 1832 2861 4837
7.75 266 471 737 1207 1887 2947 4980
8.00 273 485 758 1242 1941 3032 5124
8.25 281 499 780 1277 1996 3117 5268
8.50 289 512 801 1311 2050 3202 5412
8.75 296 526 822 1346 2105 3287 5556
9.00 304 539 843 1381 2159 3372 5699
9.25 312 553 865 1416 2214 3457 5843
9.50 319 567 886 1451 2268 3542 5987
9.75 327 580 907 1486 2323 3627 6131
10.00 335 594 929 1520 2377 3712 6275
10.25 342 607 950 1555 2432 3797 6418
10.50 350 621 971 1590 2486 3882 6562
10.75 358 635 992 1625 2541 3967 6706
11.00 365 648 1014 1660 2595 4052 6850
11.25 373 662 1035 1695 2649 4138 6994
11.50 381 675 1056 1729 2704 4223 7137
11.75 388 689 1077 1764 2758 4308 7281
12.00 396 703 1099 1799 2813 4393 7425
12.25 404 716 1120 1834 2867 4478 7569
12.50 411 730 1141 1869 2922 4563 7713

To convert to Btu/hr multiply by 3,400.
The capacities tabulated are for unvented (pressurised or sealed) heating systems.
For vented systems NABIC generally recommends Fig 542 Safety Relief Valves.
Fig 500 Safety Valves can be used for high output systems where their greater discharge capacity is advantageous.
For unvented hot water supply systems, Fig 500T Combined Pressure & Temperature Relief Valves should be used.

Fig 542 — Air

  • 10% overpressure (BS EN 4126-1)
  • Capacity: std. litres/sec · Derated discharge coefficient (Kdr): 0.19
  • First column: set pressure in bar. Size columns: DN15–DN80.
Set Pressure Bar 15 20 25 32 40 50 65 80
1.00 14 24 38 62 97 151 256 387
1.25 15 27 43 70 109 171 289 438
1.50 17 31 48 78 122 191 322 488
1.75 19 34 53 86 135 211 356 539
2.00 21 37 58 94 148 230 389 590
2.25 23 40 63 102 160 250 423 640
2.50 24 43 68 111 173 270 456 691
2.75 26 46 72 119 186 290 490 742
3.00 28 50 77 127 198 310 523 793
3.25 30 53 82 135 211 329 557 843
3.50 31 56 87 143 224 349 590 894
3.75 33 59 92 151 236 369 624 945
4.00 35 62 97 159 249 389 657 995
4.25 37 65 102 167 262 409 690 1046
4.50 39 69 107 175 274 428 724 1097
4.75 40 72 112 184 287 448 757 1147
5.00 42 75 117 192 300 468 791 1198
5.25 44 78 122 200 312 488 824 1249
5.50 46 81 127 208 325 507 858 1299
5.75 48 84 132 216 338 527 891 1350
6.00 49 88 137 224 350 547 925 1401
6.25 51 91 142 232 363 567 958 1451
6.50 53 94 147 240 376 587 992 1502
6.75 55 97 152 248 388 606 1025 1553
7.00 56 100 157 256 401 626 1059 1603
7.25 58 103 162 265 414 646 1092 1654
7.50 60 107 167 273 426 666 1125 1705
7.75 62 110 171 281 439 686 1159 1755
8.00 64 113 176 289 452 705 1192 1806
8.25 65 116 181 297 464 725 1226 1857
8.50 67 119 186 305 477 745 1259 1908
8.75 69 122 191 313 490 765 1293 1958
9.00 71 126 196 321 502 785 1326 2009
9.25 73 129 201 329 515 804 1360 2060
9.50 74 132 206 338 528 824 1393 2110
9.75 76 135 211 346 540 844 1427 2161
10.00 78 138 216 354 553 864 1460 2212
10.25 80 141 221 362 566 884 1494 2262
10.50 81 145 226 370 578 903 1527 2313

To convert to ft³/min multiply by 2.1.

Fig 542 — Steam

  • 10% overpressure (BS 6759)
  • Capacity: kg/hr · Derated discharge coefficient (Kdr): 0.19
  • First column: set pressure in bar. Size columns: DN15–DN80.
Set Pressure Bar 15 20 25 32 40 50 65 80
1.00 37 66 103 168 263 411 695 1053
1.25 42 74 116 190 298 465 786 1191
1.50 47 83 130 213 332 519 877 1329
1.75 52 92 143 235 367 573 968 1466
2.00 56 100 157 257 401 627 1059 1604
2.25 61 109 170 279 436 680 1150 1742
2.50 66 117 184 301 470 734 1241 1880
2.75 71 126 197 323 505 788 1332 2018
3.00 76 135 211 345 539 842 1423 2156
3.25 81 143 224 367 574 896 1514 2294
3.50 86 152 238 389 608 950 1605 2432
3.75 90 161 251 411 643 1004 1696 2569
4.00 95 169 264 433 677 1057 1787 2707
4.25 100 178 278 455 712 1111 1878 2845
4.50 105 186 291 477 746 1165 1969 2983
4.75 110 195 305 499 781 1219 2060 3121
5.00 115 204 318 521 815 1273 2151 3259
5.25 120 212 332 543 849 1327 2242 3397
5.50 124 221 345 565 884 1380 2333 3534
5.75 129 229 359 587 918 1434 2424 3672
6.00 134 238 372 610 953 1488 2515 3810
6.25 139 247 386 632 987 1542 2606 3948
6.50 144 255 399 654 1022 1596 2697 4086
6.75 149 264 413 676 1056 1650 2788 4224
7.00 154 272 426 698 1091 1704 2879 4362
7.25 158 281 440 720 1125 1757 2970 4500
7.50 163 290 453 742 1160 1811 3061 4637
7.75 168 298 467 764 1194 1865 3152 4775
8.00 173 307 480 786 1229 1919 3244 4913
8.25 178 316 493 808 1263 1973 3335 5051
8.50 183 324 507 830 1298 2027 3426 5189
8.75 188 333 520 852 1332 2080 3517 5327
9.00 192 341 534 874 1367 2134 3608 5465
9.25 197 350 547 896 1401 2188 3699 5603
9.50 202 359 561 918 1436 2242 3790 5740
9.75 207 367 574 940 1470 2296 3881 5878
10.00 212 376 588 962 1505 2350 3972 6016
10.25 217 384 601 984 1539 2404 4063 6154
10.50 222 393 615 1006 1574 2457 4154 6292

To convert to lb/hr multiply by 2.2.
*The minimum bore size permitted by BS specifications for steam and hot water boilers is 20mm.
Capacities given for DN15 size in the tables are for applications outside the scope of these standards.

Fig 542 — Water — Unvented System

  • 10% overpressure (BS EN 4126-1)
  • Capacity: kg/min water · Derated discharge coefficient (Kdr): 0.19
  • First column: set pressure in bar. Size columns: DN15–DN80.
Set Pressure Bar 15 20 25 32 40 50 65 80
1.00 30 53 83 136 213 332 561 850
1.25 33 59 93 152 238 371 627 950
1.50 37 65 102 167 260 407 687 1041
1.75 40 70 110 180 281 439 742 1124
2.00 42 75 117 192 301 469 793 1202
2.25 45 80 125 204 319 498 842 1275
2.50 47 84 131 215 336 525 887 1344
2.75 50 88 138 225 352 550 930 1409
3.00 52 92 144 235 368 575 972 1472
3.25 54 96 150 245 383 598 1011 1532
3.50 56 99 155 254 398 621 1050 1590
3.75 58 103 161 263 412 643 1086 1646
4.00 60 106 166 272 425 664 1122 1700
4.25 62 109 171 280 438 684 1157 1752
4.50 63 113 176 288 451 704 1190 1803
4.75 65 116 181 296 463 723 1223 1852
5.00 67 119 186 304 475 742 1255 1900
5.25 69 122 190 312 487 761 1286 1947
5.50 70 125 195 319 498 778 1316 1993
5.75 72 127 199 326 510 796 1345 2038
6.00 73 130 203 333 521 813 1374 2082
6.25 75 133 208 340 531 830 1403 2125
6.50 76 135 212 347 542 846 1430 2167
6.75 78 138 216 353 552 862 1458 2208
7.00 79 140 220 360 562 878 1484 2249
7.25 81 143 224 366 572 894 1511 2288
7.50 82 145 227 372 582 909 1536 2327
7.75 83 148 231 378 592 924 1562 2366
8.00 85 150 235 385 601 939 1587 2404
8.25 86 153 238 390 611 953 1611 2441
8.50 87 155 242 396 620 968 1636 2478
8.75 89 157 246 402 629 982 1660 2514
9.00 90 159 249 408 638 996 1683 2550
9.25 91 161 253 413 646 1010 1706 2585
9.50 92 164 256 419 655 1023 1729 2619
9.75 93 166 259 425 664 1036 1752 2654
10.00 95 168 263 430 672 1050 1774 2687
10.25 96 170 266 435 680 1063 1796 2721
10.50 97 172 269 441 689 1076 1818 2754

In the above tables, discharge capacities have been calculated in accordance with BS EN 4126-1 & BS 6759, using a derated coefficient of discharge (Kdr) 0.19, approved by AOTC.

Fig 542 — Hot Water — Unvented System

  • 10% overpressure (BS EN 4126-1)
  • Capacity: kW · Derated discharge coefficient (Kdr): 0.19
  • First column: set pressure in bar. Size columns: DN15–DN80.
Pressure Set Bar 15 20 25 32 40 50 65 80
1.00 23 41 64 106 165 258 436 660
1.25 26 47 73 119 187 291 493 746
1.50 29 52 81 133 208 325 550 833
1.75 32 57 90 147 230 359 607 919
2.00 35 63 98 161 251 393 664 1005
2.25 38 68 107 175 273 426 721 1092
2.50 41 74 115 188 295 460 778 1178
2.75 45 79 124 202 316 494 835 1265
3.00 48 84 132 216 338 528 892 1351
3.25 51 90 140 230 359 561 949 1437
3.50 54 95 149 244 381 595 1006 1524
3.75 57 101 157 258 403 629 1063 1610
4.00 60 106 166 271 424 663 1120 1697
4.25 63 111 174 285 446 696 1177 1783
4.50 66 117 183 299 468 730 1234 1869
4.75 69 122 191 313 489 764 1291 1956
5.00 72 128 200 327 511 798 1348 2042
5.25 75 133 208 340 532 831 1405 2129
5.50 78 138 216 354 554 865 1462 2215
5.75 81 144 225 368 576 899 1519 2301
6.00 84 149 233 382 597 933 1576 2388
6.25 87 155 242 396 619 966 1633 2474
6.50 90 160 250 410 640 1000 1690 2561
6.75 93 165 259 423 662 1034 1747 2647
7.00 96 171 267 437 684 1068 1804 2733
7.25 99 176 275 451 705 1101 1861 2820
7.50 102 182 284 465 727 1135 1919 2906
7.75 105 187 292 479 748 1169 1976 2993
8.00 108 192 301 493 770 1203 2033 3079
8.25 111 198 309 506 792 1236 2090 3165
8.50 115 203 318 520 813 1270 2147 3252
8.75 118 209 326 534 835 1304 2204 3338
9.00 121 214 335 548 856 1338 2261 3425
9.25 124 219 343 562 878 1371 2318 3511
9.50 127 225 351 575 900 1405 2375 3597
9.75 130 230 360 589 921 1439 2432 3684
10.00 133 236 368 603 943 1472 2489 3770
10.25 136 241 377 617 965 1506 2546 3857
10.50 139 246 385 631 986 1540 2603 3943

To convert to Btu/hr multiply by 3400.

Fig 500T — Temperature Rating

  • Temperature rating based on kW input.
  • Size columns: DN15–DN50.
Temperature Rating Based on kW Input
Size 15 20 25 32 40 50
kW 25 45 65 105 165 255

To convert to Btu/hr multiply by 3400.
The above discharge capabilities represent approximately 45% of the relief capability of the value, when steam at the pressure of 1 bar causes the thermostat to open the valve

Fig 500T — Hot Water — Unvented System

  • 10% overpressure (BS 6759)
  • Capacity: kW · Derated discharge coefficient (Kdr): 0.375
  • First column: pressure in bar. Size columns: DN15–DN50.
Pressure Rating
kW
Pressure
Bar		 15 20 25 32 40 50
1.00 46 81 127 208 326 509
1.25 52 92 144 236 368 575
1.50 58 103 161 263 411 642
1.75 64 113 177 290 454 708
2.00 70 124 194 317 496 775
2.25 76 135 211 345 539 842
2.50 82 145 227 372 582 908
2.75 88 156 244 399 624 975
3.00 94 167 260 427 667 1041
3.25 100 177 277 454 710 1108
3.50 106 188 294 481 752 1175
3.75 112 199 310 508 795 1241
4.00 118 209 327 536 837 1308
4.25 124 220 344 563 880 1374
4.50 130 231 360 590 923 1441
4.75 136 241 377 617 965 1508
5.00 142 252 394 645 1008 1574
5.25 148 262 410 672 1051 1641
5.50 154 273 427 699 1093 1707
5.75 160 284 444 727 1136 1774
6.00 166 294 460 754 1179 1841
6.25 172 305 477 781 1221 1907
6.50 178 316 494 808 1264 1974
6.75 184 326 510 836 1307 2040
7.00 190 337 527 863 1349 2107
7.25 196 348 544 890 1392 2174
7.50 202 358 560 918 1435 2240
7.75 208 369 577 945 1477 2307
8.00 214 380 594 972 1520 2373
8.25 220 390 610 999 1562 2440
8.50 226 401 627 1027 1605 2507
8.75 232 412 644 1054 1648 2573
9.00 238 422 660 1081 1690 2640
9.25 244 433 677 1108 1733 2706
9.50 250 444 694 1136 1776 2773
9.75 256 454 710 1163 1818 2840
10.00 262 465 727 1190 1861 2906
10.25 268 476 744 1218 1904 2973
10.50 274 486 760 1245 1946 3039
10.75 280 497 777 1272 1989 3106
11.00 286 507 794 1299 2032 3173
11.25 292 518 810 1327 2074 3239
11.50 298 529 827 1354 2117 3306
11.75 304 539 844 1381 2160 3372
12.00 310 550 860 1409 2202 3439
12.25 316 561 877 1436 2245 3506
12.50 322 571 894 1463 2287 3572

The above discharge capacities have been calculated in accordance with BS 6759: Part 1, using a derated coefficient of discharge (Kdr) of 0.375. They represent the steam relief capacity of the pressure eliment of the valve at 10% overpressure.

Fig 500L — Air

  • 10% overpressure (BS EN 4126-1)
  • Capacity: std. litres/sec
  • First column: set pressure in bar. Size columns: DN15–DN65.
Set Pressure Bar 15 20 25 32 40 50 65
1.00 25 44 69 112 176 274 464
1.25 28 50 78 127 199 310 525
1.50 31 55 87 142 222 346 585
1.75 34 61 96 157 245 382 646
2.00 38 67 105 171 268 418 707
2.25 41 73 114 186 291 454 768
2.50 44 78 123 201 314 490 828
2.75 47 84 132 215 337 526 889
3.00 51 90 141 230 360 562 950
3.25 54 96 150 245 383 598 1011
3.50 57 101 159 260 406 634 1072
3.75 60 107 168 274 429 670 1132
4.00 64 113 177 289 452 706 1193
4.25 67 119 186 304 475 742 1254
4.50 70 124 195 319 498 778 1315
4.75 73 130 204 333 521 814 1375
5.00 77 136 213 348 544 850 1436
5.25 80 142 221 363 567 886 1497
5.50 83 147 230 377 590 921 1558
5.75 86 153 239 392 613 957 1618
6.00 90 159 248 407 636 993 1679
6.25 93 165 257 422 659 1029 1740
6.50 96 170 266 436 682 1065 1801
6.75 99 176 275 451 705 1101 1861
7.00 103 182 284 466 728 1137 1922
7.25 106 188 293 480 751 1173 1983
7.50 109 193 302 495 774 1209 2044
7.75 112 199 311 510 797 1245 2104
8.00 115 205 320 525 820 1281 2165
8.25 119 211 329 539 843 1317 2226
8.50 122 216 338 554 866 1353 2287
8.75 125 222 347 569 889 1389 2347
9.00 128 228 356 584 912 1425 2408
9.25 132 234 365 598 935 1461 2469
9.50 135 239 374 613 958 1497 2530
9.75 138 245 383 628 981 1533 2590
10.00 141 251 392 642 1004 1568 2651
10.25 145 257 401 657 1027 1604 2712
10.50 148 262 410 672 1050 1640 2773
10.75 151 268 419 687 1073 1676 2833
11.00 154 274 428 701 1096 1712 2894
11.25 158 280 437 716 1119 1748 2955
11.50 161 285 446 731 1142 1784 3016
11.75 164 291 455 745 1165 1820 3076
12.00 167 297 464 760 1189 1856 3137
12.25 171 303 473 775 1212 1892 3198
12.50 174 308 482 790 1235 1928 3259

Fig 500L — Water — Unvented System

  • 10% overpressure
  • Capacity: litres/min
  • First column: set pressure in bar. Size columns: DN15–DN65.
Set Pressure Bar 15 20 25 32 40 50 65
1.00 54 96 151 247 386 603 1019
1.25 61 108 169 276 431 674 1139
1.50 67 118 185 302 473 738 1248
1.75 72 128 199 327 511 797 1348
2.00 77 136 213 349 546 852 1441
2.25 82 145 226 370 579 904 1528
2.50 86 152 238 390 610 953 1611
2.75 90 160 250 409 640 999 1689
3.00 94 167 261 428 668 1044 1765
3.25 98 174 272 445 696 1087 1837
3.50 102 180 282 462 722 1128 1906
3.75 105 187 292 478 747 1167 1973
4.00 109 193 302 494 772 1205 2037
4.25 112 199 311 509 796 1243 2100
4.50 115 205 320 524 819 1279 2161
4.75 118 210 329 538 841 1314 2220
5.00 122 216 337 552 863 1348 2278
5.25 125 221 345 566 884 1381 2334
5.50 127 226 354 579 905 1413 2389
5.75 130 231 361 592 925 1445 2443
6.00 133 236 369 605 945 1476 2495
6.25 136 241 377 617 965 1507 2547
6.50 139 246 384 629 984 1537 2597
6.75 141 250 392 641 1003 1566 2647
7.00 144 255 399 653 1021 1595 2695
7.25 146 260 406 665 1039 1623 2743
7.50 149 264 413 676 1057 1651 2790
7.75 151 268 420 687 1074 1678 2836
8.00 154 273 426 698 1092 1705 2881
8.25 156 277 433 709 1109 1731 2926
8.50 158 281 440 720 1125 1757 2970
8.75 161 285 446 730 1142 1783 3013
9.00 163 289 452 741 1158 1808 3056
9.25 165 293 459 751 1174 1833 3098
9.50 168 297 465 761 1190 1858 3140
9.75 170 301 471 771 1205 1882 3181
10.00 172 305 477 781 1220 1906 3222
10.25 174 309 483 790 1236 1930 3262
10.50 176 312 489 800 1251 1953 3301
10.75 178 316 494 809 1265 1976 3340
11.00 180 320 500 819 1280 1999 3379
11.25 182 323 506 828 1294 2022 3417
11.50 184 327 511 837 1309 2044 3455
11.75 186 330 517 846 1323 2066 3492
12.00 188 334 522 855 1337 2088 3529
12.25 190 337 528 864 1351 2109 3566
12.50 192 341 533 873 1365 2131 3602

To convert to galls/min multiply by 0.22.

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