Well show you how to install one. Can you connect new pipes to old lines? Cutting pipe and installing a connecting fitting. This process is not as complicated as it seems, but with patience and attention to detail, a beginning plumber can manage the job without much difficulty. · apply pipe thread tape before screwing them together, and then glue the pipes into the fittings using the proper cement. It is at least 20 years old and is leaking: Works like a charm. I want to use modern flexible hose for the new water heater, but i dont know the best way to change the existing setup. I used to oversee a lot of these pipe liner installs for sewer lines. · to install a new drain into existing sewer lines , follow these steps: Good project for do it yourself. Look no further than a tee fitting. How do you install a new plastic drainpipe? How do you connect copper pipes to old lines? Cut the old pipe , amend the gap, and run a new pipe to the desired location. · learn how to connect new pipes to existing lines in our informative articles that provide step-by-step instructions and useful tips. How do you connect a pipe to a drain line? Arrange the fittings so the water flows past the threads on the male fitting, not into them. Adding the t connection. Had it done to the pipes in my home, built in the 70s with cast iron. · how to connect pipes to old lines need to connect a new drain, vent, or supply line? My water heater is hard-plumbed with galvanized pipe. Connecting new pipe to existing drain line.