This post has been edited 2 times, last edit by "Lou2221" (Aug 27th 2010, 5:16pm)
It's the end of the pipe protruding perpendicular to the ground, not exposed, buried pipe.Is it the end of the pipe, or a mid-pipe exposure? I would never leave a piece of exposed PVC in the middle of a completed job.
What are you calling risers? Is it a 1/2" or 3/4" nipple, a pop-up spray head, or a 1/4" micro-spray semi-hard line? Normally the risers should be close to plumb. PVC nipples can bend a little in the heat, but you should be able to get them pretty close if they were installed with a swing joint. 1/4" risers will never be plumb without a stake. Some installers will perferate the poly and plug the riser in. Sometimes it's plumb, most times not, because poly will move.
Mick