Laserfiche WebLink
Assume orifice conditions exist <br />.,„�,. <br />�-�oN <br />T = -25 + �� _ -25 +� %2-2�35 = 25.62 m � r� . <br />l.j-1�,2 9 40 ,z � 0.88 <br />Vs =•36B7T - 40QoT =,2-B67 25.62) - 40(0.88)25.62 <br />T + 25 5.62 + 25 <br />= 1825.59 - 401.82 = 923.77 �r3�j�c C <br />Vtotal = Vs(A)Cfut = 923.77(0.63)0.78 = 453.94 �+3 <br />Sizinq the Orifice <br />Qallowable = 0.43 c.f.s. <br />Utilizing the orifice equation Q= cdA 2gh <br />Solving for A Q ��� = ��%• ��� <br />��'fgF�i 0.62 �d�J�.3` <br />3 1/8" = 0.0533 ft.2 <br />h = 2.5' <br />= 0.0546 ft.Z <br />If 3 1/8" orifice is used h will change G,�n <br />Solving for h=/�1 z =� 0.43 1 z = 2.�6 ' <br />l cdA/ /2g 0.62 0.0533 / �4.4 <br />Sizing the Detention System <br />Required Detention Volume = 453.94 ft.3 <br />21" pipe = 2.405 ft.3/L.F. <br />24" pipe = 3.142 ft.3/L.F. <br />Install 2- 63 L.F. 24" Hel. Alum. 16 Ga. St. Sewer Culverts at 0.50X <br />48" P1H = 12.57 ft3/'i.F. V.F. equals vertical feet abnve invert of outfall <br />CD MH No. 1 2.63 V.F. X 12.57 = <br />CB MH No. 2 2.29 V.F. X 12.57 = <br />Total Volume Provided = <br />Valume Required = <br />Excess Volume = <br />Therefore O.K. <br />395.89ft.3 <br />33.06ft.3 <br />28.78ft.3 <br />457.73ft.3 <br />453.94f1:.3 <br />3.79ft.3 <br />