Document 4aZ3VVR1moL27BNbRwp6R1e2N

American Society of Heating and Ventilating Engineers Guide, 1930 Table 5 on the basis of a demand of 25 per cent of the connected load and a 10-lb. pressure drop per 100 ft. For risers in residences use the pipe sizes in Table 1. Table 5. Amount of Water in Gallons per Minute Which Will Flow Through Various Sized Pipes for Various Pressure Drops Friction Press use Drop feb 100-PT. Run 5 7 10 20 30 40 50 75 100 125 ; 150 X -1 IX 5.4 6.4 7.6 10.8 13.2 15.0 17.0 21.0 24.0 27.0 30.0 11 13 . 15 22 27 31 35 43 49 55 . 60 19 23 27 38 47 54 60 74 85 96 105 Pipe Sizes in Inches IX . 2 2X 3 3X 4 30 : 62 109 36 74 129 43 ; 88 154 61 ! 125 218 76 153 267 86 176 308 96 197 345 117 242 423 136 i 278 . 485 152 . 311 544 166 341. 598 171 252 353 203 298 418 242 357 499 343 504 . 706 420 618 864 485 714 998 542: 800 1115 665 978 1365 769 1130 1578 858 1260 1765 939 1380 1930 Table 6. 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 m Lb. Required to Deliver Water to Top of Riser with 15 Lb. Terminal Pressure Pressure Drop per'100 Ft. - Static Head in Lb. per Sq. In. 51b. 7 lb. 10 lb. 201b. Vertical Rise of Water from Main to Highest Fixture Branch Water Pressure in Lb. Required to GrvE Adequate Service at Vertical Heights GrvENb Horizontal Run from Supply to Riser 25' 0" 50' 0" 75' 0" 100' O' 15 20.5- {.25 29.5 35 , 39.5 44 49.5 54 58.5 64 6668.5 73 77.5 6 a.83 87.5; 15 20.7 25.4 30.1 35.8 40.5 45.2 50.9 55.6 60.3 70.7 75.4 80.1 85.9 90.5 15 21 26 31 37 42 \7 53 58 63 69 74 79 84 90 95 15 22 28 34 41. 47 53 60 64 72 79 85 91 97 104 110. 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 50.30 60.63 64.96 0 10 20 30 40 50 60 70 80 90 100 110 120 130 140 150 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 4 52 * 57.3 . *62.6 " 67.7 - 73.3 a 78.6 84 89.3 * 94.6 a 100 27.8 lb. 33.1 " 38.5 " 43.8 " 49.1 " 54.5 * 59.5 " 65.1 " 70.2 75.8 81.1 " 86.5 * 91.8 " 97.1 - 102.5 * 30. 3 lb.' 35..6 " 41 46. 51. 57 62. 3 " 67. 6 a 72 .7 a 78 3 " 83. 6 a 89 94.:3 " 99. 105 . W(uci ^icsauies given in uus taDie 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. bBased upon 10 lb. pressure drop per 100 ft. run of pipe and a terminal pressure of 15 lb. at the upper most fixture. A terminal pressure of 15 lb. has been selected for operation of flush valves. For terminalp1r0elsbs.ufrreomof a1b0olvbe., vdaeludeusc.t 5 lb. from the figures given above; or for a terminal pressure of 5 lb., deduct In estimating the pipe size for any part of a riser in a building of several stories, take 60 per cent of the water to be. used on any story and all stories above as determined from Table 1 and deduct 10 per cent for each story above. This reduction in estimated amount is to take care of 400 Chapter 23--Water Supply Piping for Buildings probable use. Thus, if 100 gal. per minute are used on each story of a 10-story building the size of pipe will be determined as in Table 2. The pressure drop of 30 lb. per 100 ft. of run will give satisfactory results for branches on the top story. A higher pressure drop can be used on stories below, corresponding with the pressures as given in Table 5, which shows that for a building 100 ft. in height, a pressure drop of 100 lb. can be used on the lowest fixture branches, and that for a building 50 ft. in height, a pressure drop of 52 lb. can be used on the lowest fixture branches. Table 1, however, can be used with'safety on any of the stories but will give pipe sizes larger than necessary for the lower stories in a very tall building. Tables 3 and 4 may be used alternatively with Table 2, being adapted for very rapid determinations in the case of large apartment houses. Example: What is the riser size needed for a six-story apartment house having one bath for each apartment? Table 3 gives 2 in. diameter for all from four to twelve stories with 134 in. to supply the top story and next to top and V/i in. for story below. What is the size of riser needed for a twelve-story apartment house with three baths to each apartment? Table 3 gives 2J4 in. for all stories up to eighth floor, 2 in. for ninth, tenth and eleventh, and 1in. for top story. What is the riser size for a two-bath apartment six stories high? Table 3 gives 2 in. for the first four stories with 1Yi in. at fifth story and 134 in- on the top story. Example: What is the required size of water main for apartment house eight stories high, six apartments per story, each having three baths? Answer from Table 4 is 3 in. Example: What is the required size of main for a ten-story apartment house with six apartments per story, each having two baths? Answer from Table 4 is 334-in. main. Table 5 gives the amount of water in gallons per minute which may be passed through pipes of % in. to 4 in. diameter with pressure drops of from 5 lb. to 150 lb. per 100 ft. of run. This table may be used in sizing horizontal aijd vertical mains. For example: If the water main pressure available is known, say 90lb., and the horizontal run from water main to vertical riser is 100 ft., and the vertical riser is 100 ft. to top branch, it will require 43.31 lb. for static head (see Table 6), and 15 lb. pressure at a. minimum should be allowed for the uppermost fixture, ora total of 58.31 lb.; which would leave available for friction 90 -- 58.31 = 31.69 for friction in 200-ft. run, or 15.85 lb. per 100 ft. The main can thus be sized from the 20 lb. pres sure drop of Table 5. Example: What are the sizes required for mains and branchesjn a building 100 ft. high, supplied with a water pressure of 75 lb. per square inch with 100 gal. of water per minute required on each story? 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 shows, that a 3-in. main, reduced to 2 in. would be required. Branches to the various groups of 401 v .1