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 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.

• 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 of Pumps connected to Suction Header in Pump Room
• Fire Hydrant Pump of 2850 LPM = 1 no
• Sprinkler Pump of 2850 LPM = 1 no
• Water Curtain Pump of 2280 LPM = 1 no
• Jockey Pump of 2850 LPM = 1 no
• Flow Rate of Fire Hydrant Pump =2850 LPM= 171 M3/Hr =0.0475 M3/Sec
• Flow Rate of Sprinkler Pump =2850 LPM= 171 M3/Hr =0.0475 M3/Sec
• Flow Rate of Water Curtain Pump =2280 LPM= 136.8 M3/Hr =0.0377 M3/Sec
• Flow Rate of Jockey Pump =180 LPM= 10.8 M3/Hr =0.003 M3/Sec
• Total Flow Rate (Q) =(0.0475×1)+ (0.0475×1)+ (0.0377×1)+ (0.003×1) =1357 M3/sec
• No of Suction Pipes shall be 2 no’s
• Total Flow Rate (Q) =0.1357 /2 = 0.0675 M3/sec
• Consider Water velocity (V) = 1.5 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.0675/3.14×1.5
• Diameter of Pipe = 0.239 meter = 239 mm
• Diameter of Pipe = 250mm of 2 Nos

Calculate Size of Common Delivery Header:

• There are 4 Nos of Pumps connected to Delivery Header
• Fire Hydrant Pump of 2850 LPM = 1 no
• Sprinkler Pump of 2850 LPM = 1 no
• Water Curtain Pump of 2280 LPM = 1 no
• Jockey Pump of 180 LPM = 1 no
• Flow Rate of Fire Hydrant Pump =2850 LPM= 171 M3/Hr =0.0475 M3/Sec
• Flow Rate of Sprinkler Pump =2850 LPM= 171 M3/Hr =0.0475 M3/Sec
• Flow Rate of Water Curtain Pump =2280 LPM= 136.8 M3/Hr =0.0377 M3/Sec
• Flow Rate of Jockey Pump =180 LPM= 10.8 M3/Hr =0.003 M3/Sec
• Total Flow Rate (Q) =(0.0475×1)+ (0.0475×1)+ (0.0377×1)+ (0.003×1) =1357 M3/sec
• Consider Water velocity (V) = 3 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.1357/3.14×3
• Diameter of Pipe = 0.239 meters = 239 mm
• Diameter of Pipe = 250mm of 1 Nos

Calculate Size of Individual Suction Header of Each Pump:

• Calculate Individual Suction Header of Water Curtain Pump:
• Water curtain Pump Flow Rate (Q) =2280 LPM = 136.8 M3/Hr = 0.038 M3/Sec
• Consider Water velocity (V) = 1.5 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.038/3.14×1.5
• Diameter of Pipe = 0.180 meter = 180 mm
• Diameter of Pipe = 200mm
• Calculate Individual Delivery Header of Fire Hydrant Pump / Sprinkler Pump:
• Fire Pump Flow Rate (Q) =2850 LPM = 171 M3/Hr = 0.0475 M3/Sec
• Consider Water velocity (V) = 1.5 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.0475/3.14×1.5
• Diameter of Pipe = 0.200 meters = 200 mm
• Diameter of Pipe = 200mm
• Calculate Individual Delivery Header of Jockey Pump:
• Water curtain Pump Flow Rate (Q) =180 LPM = 10.8 M3/Hr =0.003 M3/Sec
• Consider Water velocity (V) = 1.5 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.003/3.14×1.5
• Diameter of Pipe = 0.050 meter = 50 mm
• Diameter of Pipe = 50mm

Calculate Size of Individual Delivery Header of Each Pump:

• Calculate Individual Delivery Header of Water Curtain Pump:
• Water curtain Pump Flow Rate (Q) =2280 LPM = 136.8 M3/Hr = 0.0377 M3/Sec
• Consider Water velocity (V) = 3 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.0377/3.14×3
• Diameter of Pipe = 0.128 meters = 128 mm
• Diameter of Pipe = 150mm
• Calculate Individual Delivery Header of Fire Hydrant Pump / Sprinkler Pump:
• Fire Pump Flow Rate (Q) =2850 LPM = 171 M3/Hr = 0.0475 M3/Sec
• Consider Water velocity (V) = 3 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.0475/3.14×3
• Diameter of Pipe = 0.142 meters = 142 mm
• Diameter of Pipe = 150mm
• Calculate Individual Delivery Header of Jockey Pump:
• Water curtain Pump Flow Rate (Q) =180 LPM = 10.8 M3/Hr =0.003 M3/Sec
• Consider Water velocity (V) = 3 m/sec
• Flow Rate (Q) = Area x Velocity
• Diameter of Pipe =√4Q/3.14xV
• Diameter of Pipe =√4×0.003/3.14×3
• Diameter of Pipe = 0.036 meters = 36 mm
• Diameter of Pipe = 40mm

Conclusion:

• Water curtain Pump capacity = 2280 LPM or 137 m3/hour
• Head of Hydrant / Sprinkler Pump =110 meter
• Size of Common Suction Header=2 Nos of 250mm Pipes
• Size of Common Delivery Header=1 Nos of 250mm Pipe
• Individual Suction Header of Water Curtain Pump=200mm Pipe
• Individual Delivery Header of Fire Hydrant Pump / Sprinkler Pump=200mm Pipe
• Individual Delivery Header of Jockey Pump=50mm Pipe
• Individual Delivery Header of Water Curtain Pump=150mm Pipe
• Individual Delivery Header of Fire Hydrant Pump / Sprinkler Pump=150mm Pipe
• Individual Delivery Header of Jockey Pump=40mm Pipe