Uniweld 40061 Sludge BlasterÃ† is great for unclogging a 3/4" to 1" condensate drain line without having to access the drain pan located in the A/C System's Air Handler. With the use of Nitrogen, CO2 or water the Sludge BlasterÃ† expands inside the pipe and exerts pressure blasting the clog and sludge free from the drain line. Three Easy Steps: 1.) Insert Sludge BlasterÃ† into Tee connection at the air handler, 2.) Allow nitrogen (Maximum 140 PSIG) to flow through, blasting the clog and sludge free from the drain line. 3.) Replace PVC Cap on Tee connection. For future service: Do Not Glue Permanently.