Description

The Pentair 174704 is the genuine 12-1/32 in. diameter tank o-ring. It is the seal that closes the tank when the two halves come back together, cut to the original section so it seats in the factory groove.

When you need one

Any time a tank is opened, the o-ring should be treated as a replacement item. Old rings take a set in the groove, and once they have been compressed for a few seasons they will not reseal cleanly against the mating face. A tank that weeps at the joint whenever the pump runs is usually telling you the ring is flat, nicked, or was pinched during reassembly.

Fitting it

Wipe the groove and the sealing face clean, run a thin film of silicone based o-ring lubricant around the new ring, and seat it evenly before you close the tank. Avoid petroleum based grease, which swells the rubber. Confirm the 12-1/32 in. size or part number 174704 against your equipment parts list, because tank o-rings come in sizes close enough to look interchangeable and not be.