Drain Pipe, Drains, Drain for Water cooler, Drain Line for Water Cooler, Drain Pipes
The U shaped pipe is called a p-trap which provides for a water seal between sewer gases and living space. On the back side of this p-trap, Mock Plumbing tapped a ¼” drain line for the water cooler shown in the post before this one. Also, in the top right corner, there is a point of use for tankless water heater.