Boiler Feed Pump Calculator
Calculate the required total head pressure for a boiler feed pump system.
Understanding Boiler Feed Pump Calculation
This calculator determines the total head pressure a boiler feed pump must generate to safely and efficiently supply a boiler with feedwater. Properly sizing a feed pump is critical to overcome system pressures and ensure a consistent water supply, preventing boiler damage and ensuring optimal performance.
Key Factors Explained
- Boiler Operating Pressure (PSI): The steam pressure at which the boiler operates. The feed pump must generate a higher pressure to force water into the boiler. A safety margin (typically 20 PSI or 3%, whichever is greater) is added to this value.
- Static Head (feet): The vertical distance (elevation) between the pump's centerline and the water level in the boiler drum. The pump must have enough power to lift the water this high.
- Pipe Friction Losses (feet): As water flows through pipes, fittings, and valves, it loses energy due to friction. This pressure loss, expressed in feet of head, must be overcome by the pump.
The Formula
The total head required is the sum of all pressures the pump must overcome, converted to a consistent unit (feet of head).
Total Head (ft) = (Boiler Pressure_psi + Safety Margin_psi) × 2.31 + Static Head_ft + Friction Loss_ft
This formula first converts the boiler's operating pressure from PSI to feet of head (1 PSI = 2.31 feet of head), adds a safety margin, and then includes all other system losses.
Frequently Asked Questions (FAQ)
What is 'pump head'?
'Head' is a way to express pressure in terms of the height of a column of fluid. For example, a pump that can produce 100 feet of head can lift water 100 feet straight up. It's a standard unit for specifying pump performance.
Why is a safety margin necessary?
A safety margin ensures the pump can always overcome the boiler's pressure, even with minor fluctuations in system performance. It prevents the check valve from "chattering" and guarantees a positive flow into the boiler. A common safety margin is a flat 20 PSI or 3% of the operating pressure.
How do I calculate friction losses?
Calculating exact friction losses is complex, involving pipe diameter, length, flow rate, and the number of bends and valves. For system design, engineers use detailed charts and software. For estimation, a value provided by a system designer or a conservative estimate is often used.
For a more in-depth guide, read our detailed article on this topic.