Boiler Acid Cleaning Procedure

Below shows approximate time frame for a boiler acid cleaning and responsibilities of RTA Water Treatment and customer personnel.   Also see Boiler Acid Rinse.

1st Day-Add acid cleaning solution

Set up equipment to feed acid cleaning solution into the side of the boiler;  pipe vent from top of boiler to a half full barrel of water.   Insert all handholes not already inserted, and add the remaining antifoam, inhibitor and acid to the boiler:  start firing boiler;   do adjustments in acid strength. Continue firing  the boiler, and raise temperature slowly to approximately 160 deg F. Let the boiler simmer overnight.   

Next Day -Drain acid solution, then add neutralizer

Cool boiler. Remove all handholes and completely rinse boiler from top to bottom. Inspect the inside of the boiler.   Add neutralizer, re-fill  and reheat the boiler to near boiling. At this point the cleaning process is complete.  

Boiler tubes are clean after boiler acid cleaning
Boiler tubes-Just after boiler acid cleaning, not rinsed

One or 2 days later-Drain, flush and rinse again

When boiler is cool to 140 deg F or lower, drain boiler again, take handholes out, and do another complete rinsing of boiler from to bottom. Fill and drain the boiler a second time. Install new gaskets, fill,  add antifoam, add chemical,  and get ready for operation.  (No need to rinse boiler again this time.)