Waterway Gauge Lock-Nut, 519-7441

The Waterway 519-7441 is the gauge lock-nut used on the Clearwater II cartridge and DE filters. It is the genuine Waterway part.

What it does

The pressure gauge sits in a port on the filter and the lock-nut is what holds it there. Small as it is, it is a sealing part. When it cracks or goes missing, the gauge sits loose, weeps at the port and gives you a reading you cannot trust, which matters because filter pressure is how you know when to clean the element.

Fitting

The nut is plastic, so it is meant to be snugged by hand. Reaching for a wrench is the usual way a new one gets split on the first fit. Order the gauge separately if the gauge itself has failed, since this listing covers the nut alone.