With the paint brush draw out your pipe in white. Enter 12 for the radius. You may need to alter this depending on your pipe size. You can change these settings to what you prefer if you want. Now the pipe looks a little flat.
Lets make it look more like a pipe by brightening the center with the retouch brush.
Set the retouch mode to dodge. The line width should be set to 1 or 2. I used 2. Now draw a bunch of lines like I did. Now set the layer blend mode to Soft light and lower the opacity to 70 and you should have something like the example.