Professional feedwater sizing tool for Total Dynamic Head, Pump Power, NPSH, Velocity, Density and Viscosity
These formulas are used inside the Boiler Feed Pump Calculator to convert the system pressure rise into meters of liquid head. Pdischarge and Psuction are entered as bar absolute. ρ is the water density in kilograms per cubic meter, g is gravity, and ΔZ is the system static head. This gives a more accurate estimate than applying one fixed conversion factor to every operating condition.
The Boiler Feed Pump Calculator shows both hydraulic power and shaft power so you can compare theoretical energy transfer against the actual power required after pump efficiency is considered. Motor power is also estimated with a practical allowance.
In the Boiler Feed Pump Calculator, NPSH Available is based on suction absolute pressure, suction static head, suction line loss, and the vapor pressure of water at the chosen operating temperature. This part of the calculation is essential because low NPSH can result in cavitation, unstable operation, noise, and reduced pump life.
d is the internal pipe diameter in meters. Pipe velocity matters because very high velocity can raise friction loss and create harsher flow conditions, while very low velocity can indicate oversized piping. The Boiler Feed Pump Calculator gives both metric and imperial velocity values for convenience.
This Boiler Feed Pump Calculator is designed as a practical liquid-water tool for operating temperatures from 0°C to 100°C. Within that range, the density, viscosity, and vapor pressure estimates remain suitable for quick sizing and screening work.
Boiler Feed Pump Calculator is a practical online tool built to help engineers, plant teams, maintenance staff, and technical buyers estimate the main operating requirements of a boiler feed pump. Instead of working through multiple manual conversions every time you need a quick answer, this calculator brings the most important sizing values together in one place. By entering flow rate, suction pressure, discharge pressure, water temperature, pipe diameter, pump efficiency, system static head, suction static head, and suction line loss, you can quickly review head, power, NPSH Available, fluid velocity, density, and viscosity.
A boiler feed pump works in a demanding service. It must move water at the required flow and pressure while maintaining reliable suction conditions. If the head is underestimated, the pump may fail to meet process requirements. If the power is underestimated, motor sizing can become a problem. If NPSH Available is too low, cavitation risk increases and the pump can suffer damage over time. That is why a Boiler Feed Pump Calculator is useful during planning, evaluation, comparison, and routine technical checks.
The first major output of the Boiler Feed Pump Calculator is total dynamic head. This tells you how much head the pump must develop to overcome the differential pressure plus the system static head. In simple terms, it reflects the total lifting and pressure work the pump must do. The second major output is hydraulic power. Hydraulic power shows the ideal energy transferred to the water. Shaft power then adjusts that result for pump efficiency, and motor power adds a realistic margin for practical motor selection.
Another critical area is suction performance. The Boiler Feed Pump Calculator estimates NPSH Available using suction absolute pressure, suction static head, suction line loss, and vapor pressure at operating temperature. This is important because hot water has a higher vapor pressure than cool water. As temperature rises, the suction margin becomes more sensitive. A pump can look acceptable based on pressure and head alone, yet still face cavitation if NPSH Available is not high enough. Including NPSH in the Boiler Feed Pump Calculator makes the tool much more useful for real operating review.
Start with the required flow rate in cubic meters per hour. Then enter suction and discharge pressure as absolute bar values. Add the operating water temperature because water properties change with temperature, and those changes affect the calculation. Enter pipe diameter so the Boiler Feed Pump Calculator can estimate fluid velocity. Next, enter pump efficiency to convert hydraulic power into shaft power. Finally, enter the system static head used in TDH, the required NPSH from the pump data, the suction static head, and the suction line loss. Once you click the calculate button, the results section will update instantly.
The Boiler Feed Pump Calculator is especially helpful during concept checks, equipment comparison, troubleshooting discussions, and quotation review. It is also useful when you want a fast estimate before moving into detailed engineering. Since it shows both metric and imperial conversions in several places, it becomes easier to communicate results across teams that do not all work in the same units.
If the calculator shows a high total dynamic head, you know the pump must deliver a strong pressure increase and your selection needs to match that demand. If shaft power and motor power rise sharply, you may need to review flow, efficiency, or system conditions. If velocity becomes too high, you may consider a larger pipe diameter to reduce losses. If the Boiler Feed Pump Calculator shows NPSH Available only slightly above NPSH Required, the pump may still operate, but the suction margin is tight and deserves careful review. If NPSH Available is below NPSH Required, that is a warning sign that should not be ignored.
Water density and viscosity are also included because they influence how the system behaves. Higher temperature reduces density and changes viscosity. These variations are not always dramatic, but they matter enough to affect head conversion and practical interpretation. That is why the Boiler Feed Pump Calculator does not rely on a single constant value for every condition.
This Boiler Feed Pump Calculator is intended for liquid water in the 0°C to 100°C range. It is a strong estimation tool for early sizing, technical checks, and practical analysis. Final pump selection should still be verified against manufacturer curves, actual piping layouts, detailed friction-loss calculations, and the true operating envelope of the system. Used the right way, the Boiler Feed Pump Calculator can save time, improve accuracy in early review, and make feedwater sizing much easier to understand.