Losses in Nozzles

The actual discharge from nozzles will vary from 90% to 95% of the theoretical discharge.

(Eq. 3.D.1) $$ Q = 19.636·C·{d_1}^2·\sqrt {h} $$

Where:

  • Q = Flow rate in gallons per minute
  • d1 = Nozzle Diameter in inches
  • h = Head in feet
  • C = Discharge Coefficient = 1

Theoretical Discharge of Nozzles in Gallons per Minute

Head Nozzle velocity GPM
Nozzle Diameter (inches)
(psi) (ft) (ft/s) 1/16 1/8 3/16 1/4 3/8 1/2 5/8 3/4 7/8 1 1 1/8 1 1/4 1 3/8 1 1/2 1 3/4 2 2 1/4 2 1/2 2 3/4 3 3 1/2 4 4 1/2 5 5 1/2 6
10 23.1 38.6 0.37 1.48 3.32 5.91 13.3 23.6 36.9 53 72 94 119 147 178 212 289 378 478 590 714 849 1156 1510 1911 2359 2855 3398
15 34.7 47.2 0.45 1.81 4.06 7.24 16.3 28.9 45.2 65 88 116 146 181 219 260 354 462 585 722 874 1040 1416 1849 2341 2890 3496 4161
20 46.2 54.5 0.52 2.09 4.69 8.35 18.8 33.4 52.1 75 102 133 169 209 252 300 409 534 676 834 1009 1201 1635 2135 2703 3337 4037 4805
25 57.8 61 0.58 2.34 5.25 9.34 21 37.3 58.3 84 114 149 189 233 282 336 457 597 755 933 1128 1343 1828 2388 3022 3731 4514 5372
30 69.3 66.8 0.64 2.56 5.75 10.2 23 40.9 63.9 92 125 163 207 255 309 368 501 654 828 1022 1236 1471 2002 2615 3310 4087 4945 5885
35 80.9 72.2 0.69 2.77 6.21 11.1 24.8 44.1 69 99 135 177 223 276 334 397 541 706 894 1104 1335 1589 2163 2825 3575 4414 5341 6356
40 92.4 77.1 0.74 2.96 6.64 11.8 26.5 47.2 73.7 106 145 189 239 295 357 425 578 755 956 1180 1427 1699 2312 3020 3822 4719 5710 6795
45 104 81.8 0.78 3.13 7.03 12.5 28.2 50.1 78.2 113 153 200 253 313 379 450 613 801 1014 1251 1514 1802 2452 3203 4054 5005 6056 7207
50 116 86.2 0.83 3.3 7.41 13.2 29.7 52.8 82.4 119 162 211 267 330 399 475 646 844 1068 1319 1596 1899 2585 3376 4273 5276 6384 7597
55 127 90.5 0.87 3.46 7.77 13.8 31.1 55.3 86.5 124 169 221 280 346 418 498 678 885 1120 1383 1674 1992 2711 3541 4482 5533 6695 7968
60 139 94.5 0.9 3.62 8.12 14.4 32.5 57.8 90.3 130 177 231 293 361 437 520 708 925 1170 1445 1748 2081 2832 3699 4681 5779 6993 8322
65 150 98.3 0.94 3.77 8.45 15.1 33.8 60.2 94 135 184 241 305 376 455 541 737 962 1218 1504 1820 2166 2947 3850 4872 6015 7278 8662
70 162 102 0.98 3.91 8.78 15.7 35.1 62.4 97.5 140 191 250 316 390 472 562 765 999 1264 1561 1888 2247 3059 3995 5056 6242 7553 8989
75 173 105.6 1.01 4.05 9.08 16.2 36.3 64.6 101 145 198 258 327 404 489 582 792 1034 1308 1615 1955 2326 3166 4135 5234 6461 7818 9304
80 185 109.1 1.05 4.18 9.39 16.7 37.5 66.7 104 150 204 267 338 417 505 601 817 1068 1351 1668 2019 2402 3270 4271 5405 6673 8075 9610
85 196 112.4 1.08 4.31 9.57 17.3 38.7 68.8 108 155 211 275 348 430 520 619 843 1101 1393 1720 2081 2476 3371 4402 5572 6879 8323 9905
90 208 115.7 1.11 4.43 10 17.7 39.8 70.8 111 159 217 283 358 442 535 637 867 1133 1433 1770 2141 2548 3468 4530 5733 7078 8565 10193
95 219 118.9 1.14 4.56 10.2 18.2 40.9 72.7 114 164 223 291 368 455 550 654 891 1164 1473 1818 2200 2618 3563 4654 5890 7272 8799 10472
100 231 122 1.17 4.67 10.5 18.7 42 74.6 117 168 228 298 378 466 564 671 914 1194 1511 1865 2257 2686 3656 4775 6043 7461 9028 10744
105 243 125 1.2 4.79 10.8 19.2 43 76.5 120 172 234 306 387 478 578 688 937 1223 1548 1911 2313 2752 3746 4893 6193 7645 9251 11009
110 254 127.9 1.23 4.9 11 19.6 44 78.3 122 176 240 313 396 489 592 704 959 1252 1585 1956 2367 2817 3834 5008 6338 7825 9468 11268
115 266 130.8 1.25 5.01 11.2 20 45 80 125 180 245 320 405 500 605 720 980 1280 1620 2000 2420 2880 3921 5121 6481 8001 9681 11522
120 277 133.6 1.28 5.12 11.5 20.5 46 81.7 128 184 250 327 414 511 618 736 1001 1308 1655 2043 2472 2942 4005 5231 6620 8173 9890 11769
125 289 136.4 1.31 5.22 11.7 20.9 46.9 83.4 130 188 255 334 422 521 631 751 1022 1335 1689 2085 2523 3003 4087 5339 6757 8342 10093 12012
130 300 139.1 1.33 5.33 12 21.3 47.9 85.1 133 191 261 340 431 532 643 766 1042 1361 1723 2127 2573 3062 4168 5444 6891 8507 10293 12250
135 312 141.7 1.36 5.43 12.2 21.7 48.8 86.7 136 195 265 347 439 542 656 780 1062 1387 1755 2167 2622 3121 4248 5548 7022 8669 10489 12483
140 323 144.3 1.38 5.53 12.4 22.1 49.7 88.3 138 199 270 353 447 552 668 795 1081 1412 1788 2207 2670 3178 4326 5650 7151 8828 10682 12712
145 335 146.9 1.41 5.62 12.6 22.5 50.5 89.8 140 202 275 359 455 562 679 809 1101 1437 1819 2246 2718 3234 4402 5750 7277 8984 10871 12937
150 347 149.4 1.43 5.72 12.9 22.9 51.4 91.4 143 206 280 366 463 571 691 822 1119 1462 1850 2284 2764 3290 4478 5848 7402 9138 11057 13159
175 404 161.3 1.55 6.18 13.9 24.7 55.5 98.7 154 222 302 395 500 617 746 888 1209 1579 1999 2468 2986 3553 4836 6317 7995 9870 11943 14213
200 462 172.5 1.65 6.61 14.8 26.4 59.4 106 165 237 323 422 534 659 798 950 1293 1688 2137 2638 3192 3799 5170 6753 8547 10551 12767 15194
250 578 192.8 1.85 7.39 16.6 29.6 66.4 118 184 265 361 472 597 737 892 1062 1445 1888 2389 2949 3569 4247 5780 7550 9556 11797 14274 16988
300 693 211.3 2.02 8.08 18.2 32.4 72.7 129 202 291 396 517 654 808 977 1163 1583 2068 2617 3231 3909 4652 6332 8271 10468 12923 15637 18609
Head Nozzle velocity GPM
Nozzle Diameter (inches)
(psi) (ft) (ft/s) 1/16 1/8 3/16 1/4 3/8 1/2 5/8 3/4 7/8 1 1 1/8 1 1/4 1 3/8 1 1/2 1 3/4 2 2 1/4 2 1/2 2 3/4 3 3 1/2 4 4 1/2 5 5 1/2 6
10 23.1 38.6 0.37 1.48 3.32 5.91 13.3 23.6 36.9 53 72 94 119 147 178 212 289 378 478 590 714 849 1156 1510 1911 2359 2855 3398
15 34.7 47.2 0.45 1.81 4.06 7.24 16.3 28.9 45.2 65 88 116 146 181 219 260 354 462 585 722 874 1040 1416 1849 2341 2890 3496 4161
20 46.2 54.5 0.52 2.09 4.69 8.35 18.8 33.4 52.1 75 102 133 169 209 252 300 409 534 676 834 1009 1201 1635 2135 2703 3337 4037 4805
25 57.8 61 0.58 2.34 5.25 9.34 21 37.3 58.3 84 114 149 189 233 282 336 457 597 755 933 1128 1343 1828 2388 3022 3731 4514 5372
30 69.3 66.8 0.64 2.56 5.75 10.2 23 40.9 63.9 92 125 163 207 255 309 368 501 654 828 1022 1236 1471 2002 2615 3310 4087 4945 5885
35 80.9 72.2 0.69 2.77 6.21 11.1 24.8 44.1 69 99 135 177 223 276 334 397 541 706 894 1104 1335 1589 2163 2825 3575 4414 5341 6356
40 92.4 77.1 0.74 2.96 6.64 11.8 26.5 47.2 73.7 106 145 189 239 295 357 425 578 755 956 1180 1427 1699 2312 3020 3822 4719 5710 6795
45 104 81.8 0.78 3.13 7.03 12.5 28.2 50.1 78.2 113 153 200 253 313 379 450 613 801 1014 1251 1514 1802 2452 3203 4054 5005 6056 7207
50 116 86.2 0.83 3.3 7.41 13.2 29.7 52.8 82.4 119 162 211 267 330 399 475 646 844 1068 1319 1596 1899 2585 3376 4273 5276 6384 7597
55 127 90.5 0.87 3.46 7.77 13.8 31.1 55.3 86.5 124 169 221 280 346 418 498 678 885 1120 1383 1674 1992 2711 3541 4482 5533 6695 7968
60 139 94.5 0.9 3.62 8.12 14.4 32.5 57.8 90.3 130 177 231 293 361 437 520 708 925 1170 1445 1748 2081 2832 3699 4681 5779 6993 8322
65 150 98.3 0.94 3.77 8.45 15.1 33.8 60.2 94 135 184 241 305 376 455 541 737 962 1218 1504 1820 2166 2947 3850 4872 6015 7278 8662
70 162 102 0.98 3.91 8.78 15.7 35.1 62.4 97.5 140 191 250 316 390 472 562 765 999 1264 1561 1888 2247 3059 3995 5056 6242 7553 8989
75 173 105.6 1.01 4.05 9.08 16.2 36.3 64.6 101 145 198 258 327 404 489 582 792 1034 1308 1615 1955 2326 3166 4135 5234 6461 7818 9304
80 185 109.1 1.05 4.18 9.39 16.7 37.5 66.7 104 150 204 267 338 417 505 601 817 1068 1351 1668 2019 2402 3270 4271 5405 6673 8075 9610
85 196 112.4 1.08 4.31 9.57 17.3 38.7 68.8 108 155 211 275 348 430 520 619 843 1101 1393 1720 2081 2476 3371 4402 5572 6879 8323 9905
90 208 115.7 1.11 4.43 10 17.7 39.8 70.8 111 159 217 283 358 442 535 637 867 1133 1433 1770 2141 2548 3468 4530 5733 7078 8565 10193
95 219 118.9 1.14 4.56 10.2 18.2 40.9 72.7 114 164 223 291 368 455 550 654 891 1164 1473 1818 2200 2618 3563 4654 5890 7272 8799 10472
100 231 122 1.17 4.67 10.5 18.7 42 74.6 117 168 228 298 378 466 564 671 914 1194 1511 1865 2257 2686 3656 4775 6043 7461 9028 10744
105 243 125 1.2 4.79 10.8 19.2 43 76.5 120 172 234 306 387 478 578 688 937 1223 1548 1911 2313 2752 3746 4893 6193 7645 9251 11009
110 254 127.9 1.23 4.9 11 19.6 44 78.3 122 176 240 313 396 489 592 704 959 1252 1585 1956 2367 2817 3834 5008 6338 7825 9468 11268
115 266 130.8 1.25 5.01 11.2 20 45 80 125 180 245 320 405 500 605 720 980 1280 1620 2000 2420 2880 3921 5121 6481 8001 9681 11522
120 277 133.6 1.28 5.12 11.5 20.5 46 81.7 128 184 250 327 414 511 618 736 1001 1308 1655 2043 2472 2942 4005 5231 6620 8173 9890 11769
125 289 136.4 1.31 5.22 11.7 20.9 46.9 83.4 130 188 255 334 422 521 631 751 1022 1335 1689 2085 2523 3003 4087 5339 6757 8342 10093 12012
130 300 139.1 1.33 5.33 12 21.3 47.9 85.1 133 191 261 340 431 532 643 766 1042 1361 1723 2127 2573 3062 4168 5444 6891 8507 10293 12250
135 312 141.7 1.36 5.43 12.2 21.7 48.8 86.7 136 195 265 347 439 542 656 780 1062 1387 1755 2167 2622 3121 4248 5548 7022 8669 10489 12483
140 323 144.3 1.38 5.53 12.4 22.1 49.7 88.3 138 199 270 353 447 552 668 795 1081 1412 1788 2207 2670 3178 4326 5650 7151 8828 10682 12712
145 335 146.9 1.41 5.62 12.6 22.5 50.5 89.8 140 202 275 359 455 562 679 809 1101 1437 1819 2246 2718 3234 4402 5750 7277 8984 10871 12937
150 347 149.4 1.43 5.72 12.9 22.9 51.4 91.4 143 206 280 366 463 571 691 822 1119 1462 1850 2284 2764 3290 4478 5848 7402 9138 11057 13159
175 404 161.3 1.55 6.18 13.9 24.7 55.5 98.7 154 222 302 395 500 617 746 888 1209 1579 1999 2468 2986 3553 4836 6317 7995 9870 11943 14213
200 462 172.5 1.65 6.61 14.8 26.4 59.4 106 165 237 323 422 534 659 798 950 1293 1688 2137 2638 3192 3799 5170 6753 8547 10551 12767 15194
250 578 192.8 1.85 7.39 16.6 29.6 66.4 118 184 265 361 472 597 737 892 1062 1445 1888 2389 2949 3569 4247 5780 7550 9556 11797 14274 16988
300 693 211.3 2.02 8.08 18.2 32.4 72.7 129 202 291 396 517 654 808 977 1163 1583 2068 2617 3231 3909 4652 6332 8271 10468 12923 15637 18609

Tbl. 3.D.1

For hydraulic sluicing the following pressures at base of nozzles are recommended:

Light fine material and loose sandy soil: 50 to 75 psig

Stiff loam overburden: 100 to 125 psig

Hard clay: 150 to 200 psig

The following amounts of water are recommended to move 1 cubic foot:

Heavy sand: 20 cubic feet of water

Average quarry overburden: 8 to 10 cubic feet of water

For sprinkling golf courses it is reasonably safe to figure 10 gallons per minute for each Green with 35 PSIA at hose valve outlet and 25 gallons per minute for each Fairway with 35 PSIA at hose valve outlet. The standard conditions are 100 feet of ¾ inch hose for greens sprinklers and 100 feet of 1 inch hose for fairway sprinklers. Use gate valves with a hose nipple at all outlets instead of the customary hose faucets on account of the friction loss in the hose faucets.

-

Fundamentals of Variable Speed Pumping: 1-Part On-Demand Webinar

This webinar is an introduction to variable speed pumping and how to use it for more efficient and better controlled pumping. It explains how flow and pressure are controlled with variable speed pumping and when to use each. Also covered are the devices used to achieve variable speed pumping, including variable frequency drives. The attendee will also learn the benefits provided by variable speed pumping, in relation to cost, operation, and energy savings.

Learn more

Last updated on April 19th, 2024