It pure BS, we have had the dump valves on several our rigs worked on in the past. Only to find they just cut the coroplast with a knife to access the plumbing as needed and used duct tape to re-seal their work. Very few places we had do some work for us under warranty wanted to take the time to drop the coroplast and put it back up. I thought that was supposed to happen, but industry wide it doesnt, at least around my neck of the woods.