Connect the 48-inch pipe to the bottom of the ball valve. Wrap the threaded section of pipe with Teflon tape, then screw on the bottom side of the valve (Image 1). Next, attach the upper 36-inch pipe to the top of the valve. Use Teflon tape again, to help ensure a water tight connection (Image 2). At the very top of the pipe assembly, add the 90-degree elbow, using Teflon tape to secure the connection. Make sure the elbow faces out on the same side as the valve handle, as this will eventually be mounted to a wall and the shower fixture will attach at the elbow (Image 3). Tighten connection using a pipe wrench and pliers (Image 4).
Using Teflon tape, secure the shower arm to the outward facing elbow at the top of the pipe assembly (Images 1 and 2). Next, attach the shower head to the shower arm using Teflon tape (Image 3).