ECTFE SK+ dual-laminate chimney stack

Project: Replacement of a ECTFE SK+ dual-laminate chimney stack
Location: Rio Seco, Peru
Installation: 2020
Dimension: DN 500 mm with a height of 60 m
Products: ECTFE SK+ fabric backed sheets, cap-strips and welding rod
Medien: Sulphuric acid fumes
Temperature: 80 °C
Pressure: Ambient

AGRU customers realized the replacement and installation of a ECTFE SK+ dual-laminate chimney stack for sulphuric acid fumes for a sulphuric acid plant.

The purpose of this project was the replacement of a chimney stack for a sulphuric acid plant at Rio Seco in Peru. When processing the occurring flue gases, aggressive media can form as a by-product. Since these media are very corrosive to metals and many other plastics, a dual-laminate solution using ECTFE SK+ liner material and fibre reinforced plastic (FRP) is in action. Applications made of fibre-reinforce plastics are lined with fabric backed sheets to maintain chemical resistance and leak-tightness. The FRP ensures the compressive and mechanical strength needed for a safe operation of the system, even under vacuum.


Since metals are attacked, a

dual laminate solution is used.


The job site team built and installed the replacement of the chimney stack. As part of the project preparations AGRU has had the pleasure to welcome their customers in February 2020 in Austria for a welding training and technical discussions.

The resulting cooperation was responsible for further communication with the application engineering team of AGRU during each project phase.

One of the most discussed technical challenges of this project was the conceptualization of a Y-Tee on the chimney stack. While the three dimensional geometrical form was already very demanding for the preparation of the welding process, a welding from the inside was practically impossible because of the inner diameter of 500 mm. Therefore the outer welding had to be done very carefully to ensure leak-tightness and enough mechanical strength.