Steam water chemistry is about maintaining the most optimal chemical conditions.
- To create and keep a protective layer (magnetite) inside inside boiler pipes, drum, and all other piping forming the circuit.
- Prevent corrosion inside boiler pipes, drum, turbine blades, and all other piping forming the circuit.
- Prevent deposits inside boiler pipes, drums, and on turbine blades .
The most optimal chemical values are:
- Elevated pH >9.5
- No Salts
- No Oxygen
- No Silica (sand)
- No Chlorides
- No Sulphates
- No Hardness
- No leak from heat exchangers or polluted return condensate.
How Can This Be Achieved?
To measure all of the parameters in the most accurate and quick way. Consult Watcon!
Watcon is an independent system integrator, we are free to choose both the brand and type of analyser, which is best suited to your application in terms of quality and price. Watcon’s knowledge originates from chemistry. We understand and know all analyzing principles inside out, and can therefore judge the analysers properly. We have experience with all major brands and keep close relationships with everyone, resulting in excellent buying power which in turn is of our customers benefit. Please ask.
The chemical parameters mostly measured in the steam water cycle:
- Direct Conductivity, measures all impurities (anions and cations), mostly salts that will cause corrosion.
- Cation conductivity, measures conductivity after cation filter eliminating Ammonia contribution.
- De-gassed conductivity, measures the conductivity after CO2 removal eliminating its contribution.
- pH, a very important value to prevent corrosion, activates the Ammonia and Phosphate dosing.
- pH, calculated, by measuring conductivity before and after cation filter the ammonia contribution and thus the pH can be calculated, ask for the formula.
- Dissolved Oxygen, in the lowest concentrations (< 10 ppb’s) to check the de-gasser and activate oxygen scavenger dosing.
- Silica, measured to detect carryover to the turbine blades where any deposits will cause dangerous vibrations. The silica contents are measured in the lowest concentrations (< 10 ppb’s), in mostly make up water and steam. As the value rises only slightly a continuous measurement is not necessary and the analyser might be shared.
- Sodium, Being the most accurate detection of salts, measured in the lowest concentrations (< 5 ppb, ppt’s), to prevent corrosion on pipes and turbine blades.
- TOC, (Total Organic Carbon) Often the steam generated is also used in petro-chemical processes and returns to the boiler feed water as condensate. To check if there are hydrocarbons leaked into the steam / water systems from plants processes TOC is measured.
- Chloride accelerate corrosion and stress corrosion cracking on pipes and turbine blades.
- Sulphates accelerate corrosion and stress corrosion cracking on pipes and turbine blades.
Guidelines for concentrations to keep for above chemical parameters are among others published by VGB and Siemens. Please ask.
pH, Direct- Cation – De Gassed Conductivity and Dissolved Oxygen analysers are avialable for Hazardous zones.
Silica, Sodium, TOC analysers only to be made suitable for hazardous zones in a special Ex-p cabinet, Watcon has manufactured many of these.
Spares Of Analysers
The analysers need regular maintenance and parts replacement to function correctly. This is often neglected and one of the main reasons they malfunction. We deliver spares all over the world. We also have experience with all major brands and know exactly which type of spare you need ,or have an alternative if they become obsolete.
Interested? Please ask