Hoffman Boiler Feed Pump 100HP 50 Gal 50HBFD-1520. This Continuous-duty replacement pumps fit most heating systems. Feature cast-iron volute with bronze impeller and wear ring. Float-operated internal water makeup water feeder has 1/2″ NPT connection. Water level gauge with protective brass rods and shutoff valves. Receiver has 2″ NPT low return inlet port, 2″ NPT vent line port, 2″ NPT overflow port, and 1/2″ NPT drain port. 4-bolt flange mounting. For use in small boiler feed systems for transferring condensate in steam heating or process applications.