Clean pressurised units without direct line of sight of fouled areas using Therma-Chem.

Online Cleaning Specialists
Many online cleaning companies require intensive manpower and line of sight of the fouled area within a boiler to ensure that their products can remove the ash deposition. Therma-Chem do not require this as our chemical is designed to be injected into the furnace and then react with deposits in every area of the unit due to the gasification and immense expansion of the chemical.
Our injection equipment can be set-up on a pressurised system close to the burner area and operated with minimal manpower requirements. The beauty about the chemical is that once injected into the furnace it will react with deposits throughout the unit from the furnace through to the stack. Areas that are ordinarily difficult to reach, such as the mid-bank of the superheaters and economisers, are easily cleaned using our unique technology.
pressurised units - Online Cleaning of Pressurised Units

An example of an injection system on a pressurised boiler.


Eliminate slagging and improve
heat transfer.

FS12 removes slagging from the tube walls and converts it to dry, friable powder. This results in increased heat transfer and restored capacity.


Prevent high temperature corrosion


Limit fouling and maintain flue gas velocity


Improve performance and reduce maintenance


Prevent dew point corrosion from sulphuric acid


Improve particulate removal and reduce cleaning time


Reduce NOx, SOx and
Carbon emissions


Improve performance and
prevent corrosion

How Does FS12 Work

Therma-Chem’s FS12 is an mildly alkaline solution containing nitrates that is designed specifically to clean boilers online. Using Therma-Chem’s proprietary injection system, the liquid is injected directly into the combustion chamber, vaporises and is carried by the flue gas through the unit, encountering all heat transfer surfaces including the waterwalls, superheaters, economiser, and air pre-heater.

FS12 reacts with existing hard deposits and fouling on tubes by increasing their melting point and reduces them to soft powdery ash.

This allows units to maintain high thermal efficiencies or recover capacity (if this was limited by fouling). FS12 also neutralises sulphur deposits on the cold end of the flue gas path preventing cold end corrosion and eases man entry during a maintenance or inspection shutdown.

Using FS12 ultimately results in improved heat transfer, prevention of both high temperature and low temperature corrosion, improved operating efficiency and reduced emissions.

tc product fs12 - Online Cleaning of Pressurised Units
FS12 is traditionally applied to process heaters in one of three ways


Applied daily, FS12 keeps units clean and prevents costly drop offs in performance and avoids the possible need for shutdowns during the operating campaign. This is the most common method of application with some customers having used Therma-Chem every day for 15 years across multiple units.


When a unit is load and/or temperature restricted mid-run and there is no window to shut down for maintenance, FS12 is introduced to recover performance. Injected 3-4 times per day over a period of 30-90 days, depending on the severity of the fouling, FS12 can target any part of the unit loosening deposits and restoring performance. We would then recommend switching to Maintenance Dosing to prevent a drop-off in performance recurring.


Utilised in the run up to a shutdown to facilitate a more effective and easier clean of a unit, FS12 can be applied 3-4 times per day for a period between 30 – 90 days.This ensures that during the shutdown, cleaning is more effective, easier, quicker and any vanadium pentoxide and sulphuric deposits are neutralised, dry, and entry into all areas of the unit is safe and comfortable.