Are there any good sources on the web demonstrating the differences among feedwater heater types and their operation? Also, on Canadian National at least, the later generation of locomotives were equipped with exhaust steam injectors rather than feedwater heaters. What were the advantages of the exhaust steam injector causing railways to prefer them to the traditional feedwater heater system?

Thanks.

Jason;

I believe the biggest drawback to feedwater heating systems is that they required two pumps (or one pump with two pump ends) to pump the feedwater into the feedwater heater and into the boiler itself. Since they have moving parts, they required a regular rebuild, just like the locomotive itself. Feedwater heaters would also require occasional maintenance.

In contrast, exhaust steam injectors are simple devices with no moving parts. Some railroads may have felt that the cost associated with maintaining a feedwater heating system was not worth the incremental cost savings.

I am not sure about what I am about say, but I THINK feedwater heating systems were also more sensitive about water quality. But, I am not sure about that; my thoughts come from Britian's experimenting with the French ACFI feedwater heater on a few of their locomotives. They did not have a much success as the French, and the system was not widely adopted in England.

-James Hefner
Hebrews 10:20a

Surviving World Steam Project