
Quick overview
- Genuine Sta-Rite Factory o-ring U9-371 rather than a hardware store ring in roughly the right size.
- For Cristal-Flo filters Sold as the drain cap o-ring for the Sta-Rite Cristal-Flo filter.
- Stops a weeping drain A drain cap that still drips after it is tight almost always has a flattened or cracked o-ring behind it.
- Cheap part, real leak This is one of the least expensive parts on the filter and one of the most common sources of a puddle.
- Change it while you are in there Worth swapping any time the filter is opened for a media change or a teardown.
- Lubricate before fitting Use a pool rated silicone lubricant. Petroleum grease attacks o-ring rubber and shortens its life.
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Product details
The Sta-Rite U9-371 is the drain cap o-ring for the Cristal-Flo filter. It is the seal that sits behind the drain cap at the base of the tank.
The part behind a leaking drain
Filter drains leak more often than any other point on the tank, and the o-ring is almost always the reason. Rubber that has flattened, hardened or split will not seal no matter how hard the cap is turned, and over tightening a cap to chase the drip is how caps get cracked.
Fitting it
Wipe the groove clean, give the new o-ring a light coat of silicone lubricant made for pool equipment, and hand tighten the cap. Keep petroleum grease away from it, because it swells and breaks down o-ring rubber. It is a part worth replacing on sight any time the filter is opened up.
| Brand | Sta-Rite |
|---|---|
| Manufacturer part number | U9-371 |
| UPC | 788379850968 |
| Type | Drain cap o-ring |
| Part type | Pool filter part |
| Fits | Sta-Rite Cristal-Flo filters |
| Shipping weight | 0.01 lb |
| Ships | Parcel |
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