WATER PROFILE IN STORM SEWER PIPE FROM COLLECTION PIT TO SWO CALCULATION FOR HEAD LOSS No. Pipe No. DIA.1200 DIA.1800 SI US SI US 1 Q (m3/s) or cfs 1.881 66.427 4.346 153.478 2 Length (m) or ft 218.300 716.207 831.700 2728.675 2 Hazen William Roughnesss-C 120 120 120 120 3 Diameter (m) or (in.) 1.200 47.244 1.800 70.866 4 Friction Loss, (m) or (ft) 0.418 1.428 1.043 3.563 5 Velocity (m/s) or (ft/s) 1.663 5.457 1.708 5.603 Total Energy Line Collection Pit-1 COB - 4S EL.99230 EL.97600 TOP. EL.99900 EL.98700 Entrance loss : 0.2*V2/2g=0.2*0.141=30 mm EL.99230 - 30 mm = EL.99200 Friction Loss = 418 mm Entrance loss for 3 manholes = 3*0.2*V2/2g=3*0.2*0.141 =85 mm EL.99200 - 418 mm - 85 mm = EL.98697 Velocity Head = 141 mm EL.98697 - 141 mm = EL.98556 Entrance loss at manhole is : 0.2*V2/2g=0.2*0.149 =30 mm EL.98556 - 30 mm = EL.98526 Friction Loss = 1043 mm Entrance loss for 11 manholes = 11*0.2*V2/2g=11*0.2*0.149 =328 mm EL.98526 - 1043 mm - 328mm = EL.97155 TOP. EL.99900 BOP. EL.96500 TOP. EL.98530 SWO PIPE DIA.1200 PIPE DIA.1800 218.3 M 831.7 M
wtrprof.WATER PROFILE IN STORM SEWER PIPE FROM COLLECTION PIT TO
SWOCALCULATION FOR HEAD LOSSNo.Pipe No.DIA.1200DIA.1800SIUSSIUS1Q
(m3/s) or cfs1.88166.4274.346153.4782Length (m) or
ft218.300716.207831.7002728.6752Hazen William
Roughnesss-C1201201201203Diameter (m) or
(in.)1.20047.2441.80070.8664Friction Loss, (m) or
(ft)0.4181.4281.0433.5635Velocity (m/s) or
(ft/s)1.6635.4571.7085.6036Velocity Head-V2/2g, (m) or
(ft)0.1410.4630.1490.488Note :1.Friction Loss per 1000 m (for SI)
:where :Q = the flow in m3/sD = Diameter of Pipe in mFriction Loss
per 1000 ft (for US) :where :Q = the flow in cfs (ft3/s)D =
Diameter of Pipe in in.and C = The Hazen-Williams value :for PVC =
140for concrete pipe = 1202.Velocity = Q / A (m/s for SI and ft/s
for US)whereA = sectional area of pipe (m2 for SI and ft2 for
US)3.Minor Head Loss associated with discharges are V^2 / 2g - (m
for SI and ft for US)4.Minimum Head Loss associated with entrance
losses area 0.2 * (V^2 / 2g ) - (m for SI and ft for US)5.Water
surface profile came from Bernoulli's Equation that show the energy
drop between water and pipe/manholes and show volume water still
able to pass the pipe with velocity (Q/A) > 0.4 m/s.
Total Energy LineCollection Pit-1COB - 4SEL.99230EL.97600TOP.
EL.99900EL.98700Entrance loss :0.2*V2/2g=0.2*0.141=30 mmEL.99230 -
30 mm = EL.99200Friction Loss = 418 mmEntrance loss for 3 manholes
=3*0.2*V2/2g=3*0.2*0.141 =85 mmEL.99200 - 418 mm - 85 mm =
EL.98697Velocity Head = 141 mmEL.98697 - 141 mm = EL.98556Entrance
loss at manhole is :0.2*V2/2g=0.2*0.149 =30 mmEL.98556 - 30 mm =
EL.98526Friction Loss = 1043 mm Entrance loss for 11 manholes
=11*0.2*V2/2g=11*0.2*0.149 =328 mmEL.98526 - 1043 mm - 328mm =
EL.97155TOP. EL.99900BOP. EL.96500TOP. EL.98530SWOPIPE DIA.1200PIPE
DIA.1800218.3 M831.7 MHloss per 1000 = [ 146.43 * Q / ( C * D^2.63)
]^1.85Hloss per 1000 = [ Q / ( 0.006756 * C * D^2.63) ]^1.85
