Tannins work very well in coil boilers even at high cycles. In fact, because of their effect on the magnetite layer and and their ability to descale (or prevent scaling), they protect it even better.
Below is a testimonial letter from a customer who started a brand new Miura boiler with tannins.
"Subject: Recommendation of TG3106 product for steam boiler water treatment
Every year, as part of our ISO 9001 certification, an assessment of all our suppliers has to be thoroughly done.
Several criteria are evaluated in order to obtain renewal of our corporate contractual agreement.
Services obtained by TGWT Clean Technologies in 2015 were evaluated, including the TG3106 TANNIN product supply, monthly analyses made for our Miura steam boiler, commissioning and technical support provided throughout the implementation of our new steam boiler.
Your expertise has helped us better understand the importance of having impeccable feedwater, and we are now able, through daily testing, to proactively detect anomalies on our steam system. The quality of protection attained with the TG 3106 product has been proven in both extending boiler lifetime, and in energy savings thanks to its high conductivity tolerance without creating carryover.
We are very proud of results shown in daily monitoring. Boiler probes were inspected and found to be impeccable, without any deposits. Reports issued since the installation of our boiler have clearly shown TG 3106 efficiency without the need for any other product. All checkpoints are within target. Furthermore, it is very easy to use, without the disadvantages of traditional chemical products.
With your expertise and quality of service, we have great confidence in your ability to serve our needs."