We have completed the renovation of the stack at the SARPI Dąbrowa Górnicza plant (Veolia Group), consisting in the replacement of the steel flue duct with a TWS duct. The scope of the task included design work, dismantling of the used flue duct, prefabrication of a new duct and its assembly. The design of the stack is a flue duct H = 49.5 m high and DN = 1200 mm in diameter, built into a support lattice structure with a height of about 36 m. The entire operation of replacing the stack with specialized equipment took only 3 days.