Feedwater Tank and Pump Sizing Calculator
Size a boiler feedwater tank and feed pumps from your boilers, condensate return, and safety valve setting, with an NPSH check for hot water. From the engineers at McKenna Boiler Works, Inc., a boiler manufacturer in California.
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McKenna Boiler Works, Inc.’s feedwater calculator sizes an atmospheric feedwater tank, the feed pumps, and the pump discharge pressure for one or more steam boilers, and checks pump suction (NPSH) at the tank temperature. Feedwater flow is 34.5 lb/hr per boiler horsepower plus blowdown, about 0.069 gpm per horsepower. On/off feed pumps are sized at about 1.5 times the boiler’s evaporation, modulating feed at about 1.15 times. ASME Section I PG-61 requires each means of feeding to supply water at least 3% above the highest safety valve setting. McKenna builds feedwater tanks and skid packages in Oceanside, California. Call (323) 987-1816 or email info@mckennaboiler.com.
Calculator
Size a feedwater system.
Size a feedwater system
Answer three steps. Results update as you type.
1The boilers
2Water and storage
3Feed pumps
Results
| Feedwater at full load | |
| Condensate returned | |
| Makeup water | |
| Tank water temperature | |
| Steam to preheat the tank | |
| Dissolved oxygen in the tank, at most | |
| Pump discharge pressure | |
| Pump suction (NPSH available vs required) |
Estimates for planning. McKenna engineers confirm tank, pump, and control selections before quoting. Feedwater flow uses 34.5 lb/hr per boiler horsepower, from and at 212°F, plus blowdown. Water properties from standard steam tables. Pump multipliers follow HPAC Engineering, 16 Steps to Proper Boiler Feed Pump Selection (2017). Code notes summarize ASME Section I PG-61; the boiler's code of construction and the local jurisdiction govern.