Sustainable Water Treatment For Aluminum Boilers

Program Benefits

Icon Green Chemistry TGWT

Green Chemistry

Purified tannins
Icon Surface Protection TGWT

Surface Protection

Multi-Metal Protection for:
Mild steel
Icon Heat Efficiency TGWT

Heat Efficiency

Maintaining or restoring your high heat efficiency
Icon Cleaning Closed-Loop TGWT

Cleaning the Loop

Slowly cleaning scale and corrosion by-products
Icon Easier Testing TGWT

Easier Testing

Simple, time-saving colorimetric or color comparison tests available 
Icon Safe Chemistry TGWT

Non Hazardous

Safer to handle
Non toxic
Can be sent to drain

German Engineering

Purified Tannin has been protecting heating loops since 1989 in Europe and 2005 in North America.

Beware of imitations. Tannins are complex molecules and only one program has been tested and endorsed by Patterson-Kelley.

Water Analysis in Laboratory TGWT
iPad showing PK and TGWT Water Treatment Program

About Us


Harsco Industrial Patterson-Kelley is a recognized market leader and major producer of heat transfer equipment.


Their hot water boilers and water heaters are installed in institutional, commercial, and industrial building applications such as: schools, offices, apartment buildings, dormitories, hospitals, and hotels.

Clean Technologies

TGWT, also known as The Tannin Guys®, is a leader in green chemistry, water treatment for steam boilers and closed, hot loops.

Green chemistry to improve performance without capital investment.


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