STORMWATER DRAINAGE MANUAL - Drainage … DRAINAGE MANUAL - Drainage Services ...
Drainage-Calculations-xls.xls
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Discharge Unit Values BS.5572 :1978 Type of Sanitary Fitting Interval between Use Domestic Public Peak Flow Discharge Unit (min) (min) (min) Value Automatic Washing Machine 4 10 20 5 40 WC (9 Litre Cistern) 20 7 10 14 5 28 Sink 20 6 10 14 5 27 Wash Basin 20 1 10 3 5 6 Bath 75 7 10 18 - - Shower (Per Head) Domestic 1 Public 2 Urinal Bowl 20 0.3 Discharge Unit Maximum Values BS.5572 :1978 Internal diameter Fall of pipe (mm) 1 in 111 1 in 45 1 in 22 100mm 230 430 1050 125mm 780 1500 3000 150mm 2000 3500 7500
Transcript of Drainage-Calculations-xls.xls
TablesDischarge Unit Values BS.5572 :1978Type of Sanitary FittingInterval between UseDomesticPublicPeak FlowDischargeUnit(min)(min)(min)ValueAutomatic Washing Machine41020540WC (9 Litre Cistern)2071014528Sink2061014527Wash Basin20110356Bath7571018--Shower (Per Head)Domestic1Public2Urinal Bowl200.3Discharge Unit Maximum Values BS.5572 :1978Internal diameterFallof pipe (mm)1 in 1111 in 451 in 22100mm2304301050125mm78015003000150mm200035007500Rates of Discharge from Sanitary Fittings BS.5572 :1978Type of FittingDischarge(litres per second)Basin0.60Bath1.00Sink (32mm Diameter Waste)0.50Sink (38mm Diameter Waste)1.00Sink (50mm Diameter Waste)2.00Urinal0.15WC (9 or 14 litre cistern)2.30Shower1.00Equipment Washer5.70Steam Steriliser0.95
Simultaneous DemandPeak Simultaneous DemandSimultaneous Demand FactorThe discharge unit value takes into account the number of fittings discharging simultaneouslycompared with the total number of fittings installed.m = np + 1.80 [2 np (1 - p] 0.5Where m = number of fittings discharging simultaneouslyp = tknown as the usage ratioT,n = total number of fittings installedt = time in seconds fittings are dischargingT = time in seconds between usageTotal number of fittings installed (n) = 30It has been assumed that each fitting will take 10sec to discharge their contents, and will be usedat 900sec intervalsp = 10.= 0.11900m = (30 x 0.11) + 1.80 [2 x 30 x 0.11 (1 - 0.11)] 0.5.= 5.10 + square root of 5.874.= 5.10 + 2.42.= 7.52Simultaneous Demand Factor = 7.52%
Branch CalculationsResidual Drainage Network Pipe SizingThe following calculations indicate the pipework sizes of the main horizontal sections.The size of branch mains is calculated on the basis that the discharge pipe shall be at least equalto the diameter of the outlet on the appliance to which it is connected.Section 1.Sink (38mm waste)4 x 1.00 l/s = 4.00 l/sSink (50mm waste)4 x 2.00 l/s = 8.00 l/s12.00 x 7.52% = 0.90 l/s or 0.0009m3/sQ = VA0.0009 x 8 = 0.00720.0072 / 1 x 3.142 = 0.0023mSquare root of 0.0023m = 0.048m0.048m x 1000 = 48mmSuggested horizontal pipe size is 80mm Nominal BoreSection 2.Sink (38mm waste)4 x 1.00 l/s = 4.00 l/sSink (50mm waste)5 x 2.00 l/s = 8.00 l/sEquipment Washer1 x 5.70 l/s = 5.70 l/s17.70 x 7.52% = 1.33 l/s or 0.0010m3/sQ = VA0.0010 x 8 = 0.008 m3/s0.008 / 1 x 3.142 = 0.0025mSquare root of 0.0025m = 0.05m0.05m x 1000 = 50mmSuggested horizontal pipe size is 80mm Nominal BoreSection 3.Sink (38mm waste)2 x 1.00 l/s = 2.00 l/sSink (50mm waste)7 x 2.00 l/s = 14.00 l/sEquipment Washer2 x 5.70 l/s = 11.40 l/sSteam Steriliser3 x 0.95 l/s = 2.85 l/s30.25 x 7.52% = 2.27 l/s or 0.0023m3/sQ = VA0.0023 x 8 = 0.0184 m3/s0.0184 / 1 x 3.142 = 0.0059mSquare root of 0.0059m = 0.077m0.077m x 1000 = 77mmSuggested horizontal pipe size is 80mm Nominal BoreSection A.17 Sinks @ Peak Flow = 17 x 27 = 459 Loading Units1 Washer @ Peak Flow = 1 x 40 = 40 Loading UnitsTotal Loading Units = 499 LUFrom BS 5772 :1978100mm Nominal Bore @ 1:22Section B.8 Sinks @ Peak Flow = 8 x 27 = 216 Loading Units5 Washer @ Peak Flow = 5 x 40 = 200 Loading UnitsTotal Loading Units = 416 LUFrom BS 5772 :1978100mm Nominal Bore @ 1:45
