Originally Posted By: SirTanon
Originally Posted By: earlyre
must remember to cut &post the Fl-400s i'm curently running...
Next OC will be to QSGB, was tempted, just for S's&G's, to use the QS3600 i've had in my stash for a few years, but likely will be WIX.
if anyone wants to take a REAL chance, @ my local Menards, they have about 6 LOOSE FL-500s's that have been sitting on a clearance shelf absolutely naked,(No Box, No shrink wrap, nothing) for at least 6 months, if not a year. marked for $5 ea.
I've posted this before. I run FL-400s filters in my Fusion, and have cut open quite a few of them. They've all been what I would consider to be pristine, at least for a used filter.
..and for those who doubt, here are two of them, side by side.
I suspect the main cause for problems with the FL820 is the fact that it is a larger diameter filter than the 400s, but the media isn't appropriately beefed up comparatively. It almost looks like they use the same amount of media in the 820 as they do in the 400s. Spread over a larger diameter, it just doesn't pack as tight. Just a guess though.
+1
The aspect ratio of the 400s is different. If the pleat length (end cap to end cap) / pleat depth ((OD of the media - ID of the media) / 2) is greater for the 400s, then stress on the apex of the pleat would be reduced.
This is why I have been saying it also depends on the filter design and probably the application too.