SuperPro Cover O-Ring, O-47-9

SuperPro O-47-9 is a cover O-Ring measuring 9/16 inch inside diameter with a 3/32 inch cross section. It appears in two places worth knowing about: the 2 inch Pentair push-pull valve parts, and the Purex 4000 Series molded DE filter parts covering SM and SMBW models 4024, 4036 and 4048.

Know the other numbers

The same ring is cross referenced as 272406, as O-47, and as 90-423-5113. That matters when you are working from an old diagram or a distributor list, because the number printed there may not be the one on the box. All of them point at this seal.

When to change it

Cover seals fail quietly. They do not blow out, they harden, take a permanent set where the cover has been clamped on them, and start letting water past under pressure. The test is simple: flex the old ring between your fingers. If it is stiff, cracked or has a flat pressed into one side, it is finished. Clean the groove, fit the new one with a light film of silicone based O-Ring lubricant, and it will seat evenly and come apart cleanly next time.