- Hung Vuong Plaza Electrical Work P & S CALCULATION DOMESTIC WATER TANK (a) Standard reference: Code of Practice on Water service 1981 Handbook on application for water supply 1981 Code for Practice on sanitary plumbing and Drainage system (b) Domestic water tank The following criteria ara proposed for the design of the Sanitary and Plumbing service: * Water consumption rate: + 35 – 135 litres/day/person for Podium +135 litres/day/person for Apartment *Population density: + 12m2/ person + persons/ room * Roof tank: Tower 1(8th floor – 29th floor) : 74.520 litres Safety factor: 1.1 T1 = 81.972 litres # 80 m3 Tower (8th floor – 29th floor): 74.520 litres Safety factor: 1.1 T2 = 81.972 litres # 80 m3 * Podium tank T3 = 97.327 litres # 100 m3 T4 = 97.327 litres # 100 m3 * Under ground tank: T =T1 +T2 +T3 +T4 = 360 m3 (See appendix – 01: calculation for water consumption) WATER TRANSFER PUMP B1 TO LEVEL Water pressure demand can be calculated as per formula: Hb = h1 + h2 + h3 + hi + h4 In the formula: Hb: Water pressure requirement for the water pump .h1: Height of the furthest and highest water using point to the bottom level of water tank .h2: Head loss though the water meter .h3: Pressure requirement at the water using points .hi: Total friction loss though the pipe line from the pump to the furthest and highest water using point .h4: Practical head loss of the pipe line from the pump to the furthest and highest using point Page of Specification - Hung Vuong Plaza Electrical Work We have the calculation as follows: h1 = depth 0f water tank + height of the water tank at level = + 40M h2 = h3 = hi = Total friction head loss Total length: 20 M approx 2M friction loss Fitting: 30% total length: 0.3*0.2 = 0.6M h4 = 30% hi = 0.78M Therefore: H = 43.38M With capacity: 40 M3/h WATER TRANSFER PUMP FROM LEVEL TO WATER TANK LEVEL 30 Water pressure demand can be calculated as per formula: Hb = h1 + h2 + h3 + hi + h4 In the formula: Hb: Water pressure requirement for the water pump .h1: Height of the furthest and highest water using point to the bottom level of water tank .h2: Head loss though the water meter .h3: Pressure requirement at the water using points .hi: Total friction loss though the pipe line from the pump to the furthest and highest water using point .h4: Practical head loss of the pipe line from the pump to the furthest and highest using point We have the culculation as follows: h1 = depth 0f water tank + height of the water tank at level 30 = + 75M = 75M h2 = h3 = hi = Total friction head loss Total length: 60M approx 6M friction loss Fitting: 30% total length: 0.3*6 = 1.8M h4 = 30% hi = 2.34M Therefore : H = 85.14M With capacity: 40 M3/h BOOSTER PRESSURE VESSEL OF BOOSTER PUMP FOR APARTMENT AND PODIUM Water pump plant working in auto mode, in pipe line must have pressure vessel to storage a volume (Vh) of water to reconcile differences between (Qp) and flow rate of water using (Qd) This volume of water have to be pump to the pressure of P1 When Page of Specification - Hung Vuong Plaza Electrical Work the pressure inside pipe line exceed P1, Pressure switches sent the signal to control panel to stop the water pump ( Pmax = P1) When the pressure in the water system is reduced by using of water at the tap point, sanitary fixture… Water inside the pressure vessel automatically run to the tap points by the pressure from the pressure vessel instead of pressure of the water pump Pressure inside the pressure vessel and pipe line will degrease to Pmin=m+P2, the pressure switches will sent the signal to water pump control panel to cut in the water pump The booster pump installs at top roof and supply water floors below Volume of water to reconcile the flow rate: Vh = Qp/4Z (M3) Z: Starting time of the pump per hour: Z=20 estimate Vh = 20/4*20 = 0.25 (M3) Volume of pressure vessel: V = Vh/F (M3) F: Pressure reconcile coefficient: F = (P1-P2)/P1 = (2.2-1.6)/2.2 = 0.27 Vh = 0.25/0.272 = 0.919 (M3) From these calculation, we propose 2no of pressure vessel with volume 500 litres Booster pump with H = 30M, Q = 20 M3/h PIPE SIZE The diameters of pipe shall be determined from the following formula: D = 21.68Q0.357 Where: D: internal diameter, in millimetres Q: flow rate, in litres per minute And combination with pipe size graph, pressure/flow rate tables we have main pipe sizes as follows: Transfer pump pipes Booster pump pipes Gravity supply down pipes Supply pipes for any sanitary fixtures, tap points…except for WC flush cistern 100mm 80mm 100mm 15mm All pipe sizes are shown in the drawings Page of Specification - Hung Vuong Plaza Electrical Work Page of Specification ...- Hung Vuong Plaza Electrical Work We have the calculation as follows: h1 = depth 0f water tank + height of the water tank at level = + 40M h2... reconcile coefficient: F = (P1-P2)/P1 = (2.2-1.6)/2.2 = 0.27 Vh = 0.25/0.272 = 0.919 (M3) From these calculation, we propose 2no of pressure vessel with volume 500 litres Booster pump with H = 30M,