The pp quick connect fitting is used to join copper piping together for water and gas systems that provide a watertight seal between two pipes or a pipe. Consisting of three parts, (fitting nut, olive and a coupling/valve) the diagram below shows the order in how the three parts should be installed. For good practice, it’s advised to use PTFE tape (Polytetrafluoroethylene) on the thread to ensure a sealed joint for a longer period than if you were to not put one on at all.