Step-by-Step Fire Pump Calculation (With Example) | Fire Fighting Design Guide
Fire pump calculation is a critical part of any fire fighting system design. Whether you are designing for a residential G+5 building or a commercial project, selecting the correct pump ensures adequate pressure and flow during emergencies.
This guide explains step-by-step fire pump head calculation with a practical example, based on IS 2189 and NBC 2016.
๐ What is Fire Pump Head?
Fire pump head is the total pressure required to deliver water from the source to the most critical point in the system.
It includes:
- Static Head
- Friction Loss
- Residual Pressure
๐งฎ Fire Pump Head Formula
H=Hsโ+Hfโ+Hrโ
Where:
- Hs = Static Head
- Hf = Friction Loss
- Hr = Residual Pressure
๐ข Step-by-Step Fire Pump Calculation (With Example)
๐น Step 1: Calculate Static Head
๐ Static head = vertical distance from pump to highest outlet
Example:
- Building height = 18 m (G+5)
โ Static Head = 18 m
๐น Step 2: Calculate Friction Loss
Friction loss depends on:
- Pipe length
- Pipe diameter
- Flow rate
๐ For small residential buildings, assume:
โ Friction Loss = 5โ10 m
Example:
โ Take = 7 m
๐น Step 3: Add Residual Pressure
Residual pressure ensures proper water discharge at hydrant.
โ As per standards:
- Minimum = 7 kg/cmยฒ (~70 m) for hydrant (but small buildings may use lower practical values depending on design approach)
๐ For G+5 practical design:
โ Residual Pressure = 15 m
๐น Step 4: Total Pump Head
Now calculate:
- Static Head = 18 m
- Friction Loss = 7 m
- Residual Pressure = 15 m
๐ Total:
โ Total Head = 40 m
Fire Pump Head Calculator
๐ Fire Pump Flow Requirement
For G+5 residential building:
- Hydrant System: 228 LPM
- Hose Reel: 36 LPM
๐ Total recommended pump capacity:
โ ~250โ300 LPM
๐ญ Recommended Fire Pump Brands
India:
- Kirloskar Fire Pumps
- Crompton Greaves
International:
- Grundfos
- KSB Pumps
FAQ
Q1: What is minimum fire pump head for G+5 building?
๐ Typically 35โ45 m depending on losses.
Q2: How to calculate fire pump capacity?
๐ Based on number of hydrants and flow requirement.
Q3: Is friction loss always required?
๐ Yes, it ensures accurate pump sizing.
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