I'm hoping someone can give me some help. I've got an SD80 Filter, and I'm replacing the 1.5" MPV with a 2" MPV before opening the pool for the summer. I've replaced the standpipe (with the 2" version) and replaced my sand, but I cannot get the 2" MPV to seat properly into the filter collar. If I take the o-ring out, the MPV sits directly on the collar no problem, so I know there are no mechanical obstructions with the standpipe. It appears there would be two ways that the o-ring could go on the MPV. There is a slight groove about a quarter inch from the MPV flange, and then right up against the MPV flange. I believe the o-ring is supposed to sit in the groove (that's where the o-ring was on my old 1.5" MPV), but I've tried both just to see. I put sealant/lube on the o-ring, and even applied some to the inside of the filter collar - and I cannot for the life of me get this thing to go in. I could sit on the top of this thing (I'm about 200 lbs) and I don't think it would go in. It is a little cool here, and I'm wondering if I heated up the o-ring/collar if that would help expand it enough? Does anyone have any ideas? Certainly this thing shouldn't be so hard to seat, and I don't find many other folks with this issue in my searching, so there must be something else going on here.
