Document jyYKewje3amZYkb6nX58DqQnR

American Society of Heating and Ventilating Engineers Guide, 1926-27 Table 54-B. Apartment Houses. Sizes of Water Supply Mains and Meters Based upon pressure drop of 10 lb. per 100 ft. run For 4 and 5 Stories Apartments per Floor 1 bath,, ......... . 2 baths. ........... 3 baths................ Four Gals. Main 120 160 3" 200 3" Six Gals. Main 160 3" 200 3" 240 3" Eight Gals. Main 200 3' 240 3' 280 3" Ten Gals. Main 240 3" 280 3' 320 3A" 1 bath. _ ......... 2 baths.... ............ 3 baths............... 150 190 230 For 6, 7 and 8 Stories 2H" 3" 3" 190 230 270 3" 3" 3" 230 270 310 3" 3" 3A" 270 310 350 3' 3A" 3A" For 9, 10, 11 and 12 Stories 1 bath. ......... 2 baths...... ......... 3 baths.,.............. 200 250 300 3" 3' 3A' 250 300 350 3" - 300 3 350 3A" 400 3 A" 3A' 3A' 350 400 450 Note.--The gallons per minute given above are approximated maximum demand for conditions stated. Example--What is the required size of water main for apartment house eight stories high, six apartments per floor, each having three baths? Answer from Table 54-B is 3 in. Example--What is the required size of main for a ten-story apartment house with six apartments per floor, each having two baths? Answer from Table 54-B is 3H in. main. Note.--Table 54-B 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. Table 55. Pipes may be Sized for Giving any Desired Pressure Drop per 100 Ft. of Run Friction Pressure Drop Lb. per Sq. In. per 100 Ft. Run H Pipe SrzES in Inches 1 i X IX 2 2M 3 3X 4 Gallons per Minute 5 5.4 11 19 30 62 109 171 252 353 7 6.4 13 23 36 74 129 203 298 418 10 7.6 15 27 43 SS 154 242 357 499 20 10.8 22 38 61 125 218 343 504 706 30 13.2 27 47 76 153 267 420 618 864 40 15.0 31 54 86 176 308 485 714 998 50 17.0 35 60 96 197 345 542 800 1115 75 21.0 43 74 117 242 423 665 978 1365 100 24.0 49 85 136 278 485 769 1130 1578 125 27.0 55 96 152 311 544 858 1260 1765 150 30.0 60 105 166 34! 598 939 1380 1930 102 American Society of Heating and Ventilating Engineers Guide, 1926-27 Table 56. 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 Lbs. Required to Deliver Water to Top op Riser with 15 Lb. Terminal Pressure Pressure Drop per 100 Ft. 5 lb. 15 20.5 25 29.5 35 39.5 44 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 70.7 75.4 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 lb. 15 22 28 34 41 47 53 60 64 72 79 85 91 97 104 110 Static Head in Lb. per Sq. In. Vertical Rise of Water FROM Main to Highest Branch 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 . 0 10 20 30 40 50 60 70 80T 90 100 110 120 130 140 150 Water Pressure in Lbs. Required to Give Adequate Service at Vertical Heights Given Horizontal Run from Supply to Riser 25' 0" 50' 0" 75' 0" 100' 0" 22.8 lb. 28.1 " 33.5 " . 38.8 44.1 49.5 54.8 60.1 " " " " 65.2 70.8 76.1 81.5 86.8 92.1 " " " " " " 97.5 " - 25.3 lb. 30.6 " 36 " 41.3 " 46.6 " 52 " 57.3 62.6 67.7 " 73.3 " 78.6 84 89.3 94.6 100 " " " " 27.8 lb. - 30.3 lb. 33.1 " 35.6 " 38.5 " 41 43.8 " 46.3 " 49-1 " 51.6 " 54.5 * 57 " 59.8 62.3 " 65.1 " 67.6 70.2 * 72.7 a 75.8 " a81.1 a86.5 78.3 83.6 " 89 91.8 " 94.3 97.1 99.6 " 102.5 " 105 " *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 55, 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 ib. 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.--^JVhat 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 54 and gives the pipe sizes for the main riser with a 10 lb. drop for 100 ft. of run and shows that a 3 in. main, reduced to 2 in., would be required: branches to the various groups of fixtures can be taken from Tables 55 and 56. 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 lK in. branch pipe will carry 60 gal. per minute, therefore 1 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 56 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 54 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 55 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 103