Sealing documentation over groove specification?

[Joel_Lapointe]

Hi,
We currently have a x-ring (quadring) seal that leaks. The application is an automotive actuator for offroad vehicles (ATVs...). As it is a x-ring (quadring), design documentation is more sparse than for o'rings. I try to get justification over dimensional tolerances on grooves for those seals. I've found the Eriks handbook on quadrings for general design. However I don't find more details about tolerance explainations. There isn't mush more. Is there some standards on these especially about groove tolerancing to ensure leakproofing? Especially the cylindricity as we have doubts about the ovality of our PBT-30GF plastic part.
Thank you.

 

[TugboatEng]

It is my understanding that x-rings were designed to be a drop in replacement for an o-ring and that all standard o-ring dimensioning and tolerancing should apply.

 

[3DDave]

Many times I have heard "ovality" is the problem, but it's never ovality. It's something else; wear, for example.