Description

Pentair 53108900Z is the replacement filter tank clamp spring and barrel nut, supplied as one assembly. It fits Clean and Clear Plus cartridge filters, Nautilus FNS Plus, and Titan CM and Titan RPM D.E. filters.

What it does

These filters are two piece tanks held together by a clamp band. The band is drawn tight by a threaded rod running through a barrel nut, with a spring that keeps steady tension on the joint as the tank expands and contracts. Take the spring out of the equation and the band goes slack, the o-ring stops sealing, and the filter seeps at the seam.

Common failures

Springs take a permanent set with age and heat. Barrel nuts strip or corrode. Either way the band cannot be tightened to the point where it seals, and no amount of extra force on the wrench fixes it. Replacing both pieces at once is the sensible repair, and it is worth doing while the filter is already open for a cartridge or grid service.

Check your diagram

Pentair also lists this assembly against several other filter families, including the PF stainless steel side mount sand filters and the American Products Quantum cartridge filters. If your model is in one of those ranges, confirm the part against the parts breakdown for your filter before ordering.