Help: Pentair Nautilus NFS DE buttress removal tool/instructions


New member
Sep 16, 2016
I've had a leak on the bottom of my Pentair/PacFab Purex Triton Nautilus FNS DE filter tank for a few seasons now and after replacing the locknut, lower pipe, gaskets/o-ring, and even silicone sealing around the locknut/lower pipe I'm left with trying to replace the buttress adapter (pentair part# 19-5221). I ordered a new one along with the o-ring, but can't figure out how to get the old one off. Does anyone know how to remove and replace it?

I tried tapping a block of wood with a mallet against the raised ridges and just chipped a couple. Also tried to grab across a couple with a wrench, but it wouldn't budge. My guess is there's some kind of special tool for it (I've seen things which look like they may work, but are built for newer filters). I'm also open to 3D printing something if someone has a plan for one.

If all else fails, I may try flexi-tape all around the outside edge... but that's not my first choice.