Agenda - Council - 06/27/2017 - Laserfiche WebLink

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TABLE Minimum Specified Time Required for a 0.5 psig Pressure Drop for Size and Length of Pipe Indicated for Q = 0.0015 CFM/SF Pipe Minimum Length for Time for Diameter Time Min. Time increased Specification Time for Length (L) Shown (Min:Sec) (Inches) (Min:Sec) (Feet) Length (Sec) 100 Ft. 150 Ft. 200 Ft. 250 Ft. 300 Ft. 350 Ft. 400 Ft. 450 Ft. 4 1:53 597 6 2:50 398 0.190 L 1:53 1:53 1:53 1:53 0.427 L 2:50 2:50 2:50 2:50 0.760 L 3:47 3:47 3:47 3:47 1.187 L 4:43 4:43 4:43 4:57 1:53 1:53 2:50 2:50 8 3:47 298 3:48 4:26 10 4:43 239 5:56 6:55 12 5:40 199 1.709 L 5:40 5:40 5:42 7:08 8:33 9:58 15 7:05 159 2.671 L 7:05 7:05 8:54 11:08 13:21 15:35 18 8:30 133 3.846 L 8:30 9:37 12:49 16:01 19:14 22:26 21 9:55 114 5.235 L 9:55 13:05 17:27 21:49 28:11 30:32 24 11:20 99 6.837 L 11:24 17:57 22:48 28:30 34:11 39:53 45:35 51:17 *27 12:45 88 8.653 L 14:25 21:38 28:51 36:04 43:18 50:30 57:42 64:54 *30 14:10 80 10.683 L 17:48 26:43 35:37 44:31 53:25 62:19 *32 15:35 72 12.926 L 21:33 32:19 43:56 53:52 64:38 75:24 *3EI 17:00 66 15.384 L 25:39 38:28 51:17 64:06 76:55 89:44 102:34 115:23 1:53 1:53 2:51. 3:12 5:04 5:42 7:54 8:54 11:24 12:50 17:48 20:02 25:38 28:51 34:54 39:16 71:131 80:07 86:10 96:57 *NOTE - Consult with pipe and appurtenance manufacturer for maximum test pressure for pipe size greater than twenty four inches (24") in diameter. FORMULA The formula below calculates the specified minimum time required for a 1.00 psig pressure drop from a starting pressure of 3.5 psig to a final pressure of 2.5 psig using a leakage rate of 0.0015 cubic feet/minute/square foot of internal surface. Calculate all test times by the following formula: T= 0.085 DK/Q where: T = shortest time allowed for the air pressure to drop 1.0 psig, sec. K = 0.000419 DL but not less than 1.0, Q = leak rate = 0.0015 CFM/SF, D = measured average inside diameter of sewer pipe, in., and L = length of test section, ft. E2 Hydrostatic Test Method E2a Gravity Sewers After bulkheading the test section, the pipe shall be subjected to a hydrostatic pressure produced by a head of water at a depth of three feet (3') above the invert elevation of the sewer at the upstream manhole of the test section. In areas where ground water exists, this head of water shall be three feet (3') above the existing water table. The water head shall be maintained for a period of one (1) hour during which time it will be presumed that full absorption of the pipe body has taken place, and thereafter for an extended period of one (1) hour the water head shall be maintained as the test period. During the test Page 52