Boiler servicing

Hi all !
I'm going on with another technical subject : Boiler servicing.

I wonder what was the D&RGW, and what are the C&TS and D&S (or any other railroad) boiler servicing practices. Boiler blowdown frequency, how boiler washings are made and frequency. Is there any water chemical treatment used.

Our railroad uses a chemical against hard water and corrosion.
Unfortunately, for 7 years proportioning was not enough due to bad advices. We corrected this 3 years ago, but the just 10 years old boiler now has corrosion at the bottom of boiler barrel (we'll see what the boiler inspector will say).
Also a lot of dirt, although we do a boiler blowdown each end of day (but maybe it's not enough). In addition, it's a smaller and simpler boiler than on a bigger engine, so it's fitted with just one blowdown valve, at the front left bottom of the firebox.

So we are looking around to understand practices on other railroads, and I assigned myself seek on US side.

Thank you to everyone that may help !

------------------------------------------------------------
Sebastien
SNCF passenger trains engineer
Volunteer on the "Chemin de Fer de Rillé" (60cm/2ft, France)
www.aecfm.fr
cfrtrain.blogspot.fr