Document mB6yXw1E1jq89pnKV2Mdv8Xgb

American Society of Heat.ng and Ventilating Engineers Guide, 1928 Table 4. Apartment Houses. Sizes of Water Supply Mains and Meters Based upon pressure drop of 10 lb. per 100 ft. run 1 bath--.......... 2 baths.--........... 3 baths-............. Apartments per Floor Four Gal. Main 120 iw 160 3" 200 3" Six I Gal. Main j ~~16(P ~ 3'" 200 3" 240 3" -I Eight GaL Main 200 3" 240 3" 280 3" ------------------ | TiIN I.W.. 240 3" 280 3" 320 3K" 1 bath-------------2 baths.------------] 3 baths.----- 150 190 230 For 6, 7 and 8 Stories Wz" 3" 3" 190 230 270 3" 3" 3" 230 270 310 3' 3' 354' 270 310 350 3" 354" 3H' 1 bath-- 2 baths-- 3 baths--........ For 9, 10,11 and 12 Stories 200 250 300 3" 250 3" 300 3^' 350 1U zl 3" 3W 354' 300 354' 350 3M' 350 3H" 400 3)4" 400 354' 450 .___ nJ--------------------------------------:------- ------------------------ , Example--What is the required size of water main for apartment house eight stories high, six apartments per floor, each having three baths? AEnxsawmeprlef--roWm hTaatbilse 4thies r3eiqnu.ired size of main for a ten-story apartment house with six apartments per floor, each having two baths? -. Answer from Table 4 is 3^ in. main. ; Note.--Table 4 gives the sizes of mains for apartment houses of one. two or three baths for each apartment, and with four, six, eight or ten apartments per floor and from four to twelve stories in height. Pressure Drop per 100 Ft. Table 5. Pipes may be Sized for Giving any Desired Friction Pressure Drop Lb. per Sq. In. per 100 Ft. Run 'A 5 7 10 20 5.4 6.4 7.6 10.8 30 40 50 75 100 13.2 15.0 17.0 21.0 24.0 125 150 27.0 30.0 1 11 13 15 22 27 31 35 43 49 55 60 Pipe Sizes in Inches 1H l H 2 2H . Gallons per Minute 3 19 23 .27 38 47 54 60 74 85 96 105 30 36 43 , 61 76 86 96 117 136 152 166 62 74 88 125 153 176 197 242 278 311 341 109 129 154 218 267 308 345 423 485 544 598 . 171 203 242 343 420 485 542 665 769 858 939 150 .4 252 298 357 504 618 714 800 978 1130 1260 1380 353 418 499 706 864 - 998 1115 1365 1578 1765 1930 . . Chapter VI--Piping for Water Supply Systems Table 6- Showing Water Pressure Required to Deliver Water to Top of Vertical Riser with 15 Lb. Pressure at the Top Branch and to Give Adequate Service at Vertical Heights Given Water Pressure in Lb. Required TO DEI .iver Water to Top op Riser WITH 15 Lb. Terminal Pressure Pressure Drop per 100 Ft. 5 lb- 35 39.5 49.5 54 58.5 64 68.5 73 77.5 83 87.5 7 lb. 15 20.7 25.4 30.1 35.8 40.5 45.2 50.9 55.6 60.3 . 66 70.775.4 80.1 85.9 90.5 10 lb. 15 21 26 31 37 42 47 53 58 63 69 74 - 79 84 90 95 20 ib. 15 22 28 34 41 47 53 60 64 72 79 85 91 97 104 110 Static Head in Lb. PER Sq. In. 0 4.33 8.66 12.99 17.32 21.65 25.99 30.32 34.65 38.98 43.31 47.64 51.97 56.30 60.63 64.96 Vertical Rise op Water from Main to Highest Fixture Branch o b cs Water Pressure in Lb. Required to Give Adequate Service at Vertical Heights Given Horizontal Run from Supply to Riser 50' 0" 75' 0" 100' 0" 0 22.8 Ib. 25.3 lb. 27.8 lb. 30.3 lb. 10 28.1 " 30.6 33.1 " 35.6 " 20 33.5 " 36 " 38.5 " 41 30 38.8 " 41.3 43.8 " 46.3 " 40 44.1 " 46.6 " 49.1 " 51.6 " 50 49.5 * 52 54.5 57 " 60 54.8 w 57.3 " 59.8 " 62.3 " 70 60.1 " 62.6 * 65.1 " 67.6 " 80 65.2 " 67.7 " 70.2 " 72.7 " 90 70.8 " 73.3 * 75.8 " 78.3 " 100 76.1 " 78.6 * 81.1 83.6 " 110 81.5 " 84 * 86.5 " 89 " 120 86.8 " 89.3 * 91.8 " 94.3 " 130 92.1 " 94.6 97.1 " 99.6 " 140 97.5 " 100 * 102.5 * 105 " 150 *Note.--The water pressures given in above table are the pressures at the base of the riser, necessary to deliver water to top of riser with a terminal pressure of 15 lb. when discharging the number of gallons per minute called for in Table 5, at the pressure drop indicated. **Note.--Based upon 10 lb. pressure drop per 100 ft. run of pipe and a terminal pressure of 15 lb. at the uppermost fixture.. A terminal pressure of 15 lb. has-been selected for operation of flush valves. For terminal pressure of 10 lb., deduct 5 lb. from the figures given above; or for a terminal pressure of 5 lb. deduct 10 lb. from above values.. Example.--What are the sizes required for mains and branches in a building 100 ft. high, supplied with a water pressure of 75 lb. per sq. in. with 100 gal. of water per minute required on each floor? This is worked out in Table 2 and gives the pipe sizes for the main riser with a 10 lb. drop for 100 ft. of run and shpws that a 3 in, main, reduced to 2 in., would be required: branches to the various groups of fixtures can be taken from Tables 5 and 6. On the top floor it will be necessary to use a 1H in. branch to carry 60 gal. per min. with a pressure drop of 30 lb. but that at 30 ft. vertically from the supply, a l} in. branch pipe will carry 60 gal. per minute, therefore 1 l/i in. pipe could be selected for this branch. Assuming that the pressure drop in the main riser is 10 lb. per 100 ft. run and the pressure drop on the top floor in the branch does not exceed 15 lb. in all and the static head for building 100 ft. as given in column 2 of Table 6 is 43.31 lb. making a total of 58.31 lb.; it will be seen that 75 lb.--58.31 lb., which equals 16.59 lb'., is the amount of pressure over and above that required, and that this pressure can be utilized to overcome the friction drop in the main feed line running from the source of supply to the base of the riser. ' From Table 2 it is found that 240 gal. per min. will flow at the first floor, and assuming that this water supply is to be brought in a main 300 ft. long; Table 5 will show that a 3/^ in. supply would be necessary. Example--What pressure is required in the water supply main to give 15 lb. pressure, at the uppermost fixture in a building where the riser is 100 ft. high and is located 75 ft. from the water main in a horizontal direction, when the other fixtures within the building are in use to their estimated average capacity? Answer is found to be 75.8 lb. at the intersection of 100 ft. vertical height and 75 ft. horizontal run. Note.--If only 10 lb. be required at the uppermost fixture, then 70.8 lb. would be the answer. WHEN TANK IS ON ROOF If tank is elevated about 35 ft. above highest fixture, which would be about 25 ft. above the roof, similar computations will apply for branch connections and main risers except that the main riser will have its 151