E-ring keeps breaking on filter box

[tim_schandorff]

I have a Hayward star clear plus filter and it has an e-ring that keeps the knob from coming out of the box when you open the filter for cleaning. I have already replaced 3 of these e-rings because they break. I now have an aquarite system so I'm wondering if the salt is the problem. That said I did replace one or two of these before converting to a salt system. Is there an aftermarket part that won't corrode like this one does or is there a way to treat it? I should also mention that the chemicals have been well maintained so the PH hasn't been off for any length of time.

Thanks for any advice you might have. Also is there a good parts dealer that would sell this at a reasonable price? I have seen it for anywhere from $5 with $9 shipping to $20

 

[gtemkin]

Maybe the E-rings you've been given are the wrong material or the wrong size (overstressed upon installation).

I'm not familiar with your filter but if it's a standard E-ring, which I got to believe it is, you should be able to get a replacement dirt cheap from a good hardware supplier.

Here's a link to McMaster-Carr who sells 3/8" stainless steel E-rings for $4.45 for a package of 10. I don't know that is the correct size, just using it as an example.

http://www.mcmaster.com/#retaining-rings

Click on the "Side-Mount External Retaining Rings (E-Style)" to see all the sizes, materials and prices available.