According to the EPRI Revised Wet Stack Design Guide, chimneys lined with certain borosilicate lining systems can be operated safely, without spitting at velocities up to 18.3 m/s. The NTPC Barh Unit 1 power station in Bihar will be using its existing chimney as an FGD wet stack after commissioning of its FGD system, being installed by BHEL. The flue gas velocity in this chimney however will be significantly higher than the recommended 18.3 m/s. The supplier of the chimney lining system to BHEL, Hadek, offers a unique patented solution for this chimney, to safely handle the wet flue gas stream at these greater flue gas velocities. Hadek is the global supplier of the Pennguard lining system manufactured in USA and has supplied Pennguard linings to more than 142 power station chimneys worldwide. The unique lining system pattern has been tested for handling flue gas velocities up to 22.9 m/s and will help to prevent stack liquid discharge from this chimney flue.