When you make a smartpipe, go the bottom of the screen and make sure the selection tools are visible (if the aniamtion tools are there, click the gridded ball on the right) Click the metaball icon down there to select all metaballs. With them selected, change the family color to something non-typical (like dark green or dark blue). Now select the family you just defined by looking for the family select pulldown in the selection tools at the bottom (looks like a gradientsqaure, toward the right side of the tools along the bottom) Now with these selected, you may enetr the material la or apply any preset. This way, when you create a new smartpipe, you select all metaballs again, but then shift-select the previous family color to de-select the first smart pipe and leave the balls of the second selected. Make these another family for easy selection. I know this sounds complicated in writing, but once you do it it isn;t too bad.