I’m replacing (trying) the Pentair 6 way valve atop a 145241 Tagleus filter. Number on old part is 272526, which is superceded (as far as I can tell. No matter the source, it gets changed) to 262506. Everthing is copacetic, till I try to button up the 2-piece clamp. No way will the O ring that came with the valve compress enough to slide the clamp over the flange of the filter and the bottom flange of the valve.
Any ideas?