Boiler Alkaline Boil Out Procedure

ORGANIC BOILING OUT FOR BOILERS

Alkali Boil Out for New & Old Boilers

FINEAMIN® products represent a greener alternative, but with the same metal passivation properties, to the conventional boiler boil out procedure using caustic soda, sodium carbonate, sodium phosphate. The boiler water is strongly alkalized in such way that the manufacturing residues, grease, shavings, loose tinder and dirt and/or other impurities (e.g.: iron oxides) are removed from the metal surface while slowing down any corrosive reactions.

But compared to traditionally used products, the effect of the  alkalizing amines found in FINEAMIN® water treatment chemicals are highly improved by a strong dispersing effect on the impurities due to the additional content of polymers. All dispersed impurities can easily be removed from the boiler by blowdown.

Furthermore, the most important characteristic of FINEAMIN®, alkali boil out chemical mixture, is the formation of the protective polyamine layer on all surfaces inside the boiler during boiling out. This protective layer enables corrosion prevention for the whole period between boiler boil out procedure and its normal operation start-up.

metal passivation

Why Boil-Out Is Needed

Conventional Methods & Drawbacks

  • Removes grease, oil, welding residues, metal shavings, and other contaminants left from manufacturing or installation.
  • Ensures both water space (boil-out) and vapor space (blow-out) are cleaned and passivated.
  • Protects downstream equipment (superheaters, turbines) by minimizing risk of corrosion and deposits.
  • Acid Cleaning: Expensive safety measures, disposal challenges, risk of damaging boiler.
  • Trisodium Phosphate: Disposal issues, phosphate deposits, “hide-out” effects, no dispersing capacity, not steam-volatile, long blow-out time.
  • Caustic Soda: Dangerous handling, risk of stress corrosion cracking, no dispersing effect, longer blow-out.
  • Demineralized Water Alone: No cleaning/dispersing effect, very long process.

Advantages of Filming Amines & Alkali Boil Out  vs. Caustic Soda

  • Stronger cleaning effect boiler boil out procedure due to the combination of surface active polyamines and dispersing polymers.
  • Can be done simultaneously with the drying of the brickwork.
  • No more risky boil out chemicals (e.g.: caustic soda) that could endanger the plant.
  • Easy handling. No special protection equipment needed (just the usual googles and gloves).
  • Helps in reaching steam purity faster due to shorter blowout procedure.
  • OEM-compliant, respecting specifications of boilers & turbines manufacturers.
  • Film-forming capacities of the polyamines, that improve the quality of the magnetite layer during alkaline boil out.
  • Has less impact on the environment on disposal. Up to 80% biodegradable.
  • Involves no special regulations for products storage.
boiler before alkali boil out

Before boil out procedure

After boil out procedure with filming amines / Fineamin

Water tube boiler 112 bar / 125 t/h. Images copyright:  CWB Wasserbehandlung GmbH

Step-by-Step Alkaline Boil-Out Procedure

Below you will find a pdf in which we put together a concise roadmap of the recommended sequence when performing an alkaline boil-out using filming amines. It outlines the core phases—preparation, active boil-out, and cleanup—so the operator can follow a clear, methodical path from start to finish. Each step ensures that the system is cleaned, protected, and ready for safe operation.

Still, before performing any boil out procedure, please do contact us.

The boiling out procedure

Download Full Instructions For Boiling out with FINEAMIN 15

For precise instructions and dosage on alkali boil out and blow out using FFA, please download the following pdf: boiler boiling out using film-forming amines procedure.

 

Monitoring the Boil Out Example

The progress of an alkaline boil-out can be clearly followed through systematic sampling and analysis. Parameters such as pH, conductivity, dispersant concentration (POC), and dissolved iron are tracked every few hours. As shown in the picture below, water samples gradually become lighter and cleaner, confirming both the removal of residues and the formation of a protective magnetite layer.

👉 All details of the recommended procedure and monitoring practices are explained in our latest Fineamin webinar.

Boil Out Monitoring by CWB Wasserbehandlung GmbH

CONTACT US for more details
Scroll to Top