12. Calculate Size of Water Curtain Pump / Head of Fire Pumps / Pipe Size of Suction & Delivery Header.

CALCULATE SIZE OF WATER CURTAIN PUMP / HEAD OF FIRE PUMPS / PIPE SIZE OF SUCTION & DELIVERY HEADER.

April 3, 2025 1 Comment

Calculate Size of Water Curtain Pump , Head of Fire Pumps along with Pipe size of Suction & Delivery Header.

CALCULATE SIZE OF WATER CURTAIN PUMP:

As Per water curtain requirement, required minimum pressure of 1.6 kg/sq.cm at the last nozzle of water curtain. * Total Length of Pipe Network for water curtain in one zone = 84 meter. * Spacing between Open Nozzle =2.5-meter Nozzle to Nozzle * Calculation: * No of Nozzle = Total Length of Pipe / Spacing between Nozzle * No of Nozzle = 84 / 2.5 = 34 Nos. * The flow through each nozzle Q = K x P (As per IS: 9972/ NFPA 13) * Where * Q = Flow in lpm flowing through nozzle * K = Nozzle Factor = 40 (As per manufacturer) * P = Total Pressure in Bar at flow Q = 1.6 bar * The flow through each nozzle Q = K x P =40 x 1.6 * The flow through each nozzle Q =64 LPM * Total Flow rate required= No Nozzle x Flow on Each Nozzle * Total Flow rate required= 34 x 64 * Total Flow rate required= 2176 LPM or 130.56 m3 /Hour * Maximum water curtain Pump capacity required= 2280 LPM or 137 m3/hour

CALCULATE PUMP HEAD FOR WATER CURTAIN PUMP:

Head requirement for Fire Pump has been decided as below * As Per water curtain requirement, required minimum pressure of 1.6 kg/sq.cm at the last nozzle of water curtain. * Calculate Total Length of Pipe: * Note: Considering that basement shall be provided the water curtain system: * Total Vertical Length of Pipe from Plant Room to remotest water curtain = 10 meter * Total Horizontal Length of Pipe from Plant Room to remotest water curtain= 50 meter * Total Length of Pipe from Plant Room to remotest water curtain = 50+10=60 meter * Equivalent Length of Pipe Due to Fittings @ 10 %= 6 meter * Total Length of Pipe = 65 meters * Calculate residual Head: * Required Residual head= Required minimum Pressure at last Point * Required Residual head= 1.6kg/sq.cm = 1.6×10.00=16 meters. * Calculate Head loss in Pipe: * Head Loss in bar (As per Hazen William’s formula) (H) = (6.05 x 10^5 x Q^85 x L) / (C^1.85 x d^4.87) * Where L = Length of pipe in meters * Q = Discharge in Lpm * C = Hazen-Williams roughness coefficients * D = Dia. of pipe in mm * H = Head loss in bar.

Pipe Material Hazen-Williams roughness coefficients (C) Cast Iron (unlined) 100 to 120 Cast Iron (lined) 130 Ductile Iron (cement lined) 140 Steel (new) 140 Steel (galvanized) 120 Copper 140 to 150 PVC and Plastic 140 to 150 Asbestos Cement 140 to 150 Concrete 100 to 140 Corrugated Metal 60 to 150 Riveted Steel 90 to 110 Vitrified Clay 110 to 140

Here L = 65 m * Q = 1280 Lpm * C = 120 (As per Table) * D = 150 mm * Head Loss in bar (H) = 6.05 x 10^5 x 2280^85 x 65 / 120^1.85 x 150^4.87 * Head Loss in bar (H) = 0.23 bar or 2 meters * Calculate Total Head of Water Curtain Pump: * Total Head of Pump = Static Head (Vertical) + Residual Head + Head loss in Pipe * Total Head of Pump = 10+16 + 2 =28 meter * Total Head of Pump =30 meter

CALCULATE PUMP HEAD FOR HYDRANT PUMP:

Head requirement for Fire Pump has been decided as below * As Per NBC Rule, there shall be minimum pressure of 3.5kg/sq.cm at the highest Fire Hydrant * Calculate Total Length of Pipe: * Total Vertical Length of Pipe from Plant Room to remotest Fire Hydrant = 64 meter * Total Horizontal Length of Pipe from Plant Room to remotest Fire Hydrant= 80 meter * Total Length of Pipe from Plant Room to remotest Fire Hydrant = 64+80=144meter * Equivalent Length of Pipe Due to Fittings @ 10 %= 158.4 meter * Total Length of Pipe = 159 meters * Calculate residual Head: * Required Residual head= Required minimum Pressure at last Point * Required Residual head= 3.5kg/sq.cm = 35 meters. * Calculate Head loss in Pipe: * Head Loss in bar (As per Hazen William’s formula) (H) = (6.05 x 10^5 x Q^85 x L) / (C^1.85 x d^4.87) * Where L = Length of pipe in meters * Q = Discharge in Lpm * C = Hazen-Williams roughness coefficients * D = Dia. of pipe in mm * H = Head loss in bar.

Here L = 159 m * Q = 2850 Lpm * C = 120 (As per Table) * D = 150 mm * Head Loss in bar (H) = 6.05 x 10^5 x 2850^85 x 159/ 120^1.85 x 150^4.87 * Head Loss in bar (H) = 0.85 bar or 9 meter * Calculate Total Head of Fire Pump: * Total Head of Pump = Static Head (Vertical) + Residual Head + Head loss in Pipe * Total Head of Pump = 64+35 + 9 =108 meter * Total Head of Pump =110 meter

CALCULATE SIZE OF COMMON SUCTION HEADER:

There are 4 Nos …