Replace O-Rings with Quad-rings?

I am chasing hydraulic leaks on equipment and where there are standard round o-rings, on suggestion from local supplier, I am thinking to replace with quad-rings (x-ring is another name for them). I can not see a downside but there must be one and I am missing it. Immediate items are rotating shaft on forklift mast that holds the spool for the sideshift hoses, other is a rotating hydraulic swivel or rotary manifold. Not to worried about cost as there are not many and all are cheap. Both of these are a pain to take apart and change so I would like the upgrade to be as long lasting as possible.

I'd read the Parker O-Ring Handbook section on how O-rings work, and what's necessary for them to work well. X-Rings are not necessarily better, or worse. Depends on the job the ring is supposed to do.

www.parker.com/Literature/O-Ring Division Literature/ORD 5700.pdf

I'd read the Parker O-Ring Handbook section on how O-rings work, and what's necessary for them to work well. X-Rings are not necessarily better, or worse. Depends on the job the ring is supposed to do.

www.parker.com/Literature/O-Ring Division Literature/ORD 5700.pdf

Thanks Joe, there is a lot of info to digest in there. Just did a quick scan but saw very little on x-rings, will look in more detail later when time allows.

The Parker guide is a great starting point to understanding o-rings, but that's about all it covers. There are some other options for drop-in replacements, but they are almost all more expensive than an o-ring.

Do you know what the failure mode is? What kind of damage did the seals show when they came out? If the seals don't look bad it's possible that there is another issue on the metal side. If you have a scored bore or groove somewhere it won't matter what seal you put in, you will be chasing the leak forever.

Edit: forgot to mention, the biggest improvement of a quad ring over an o-ring is resistance to spiral failure. It's a lot more stable inside the groove because the four lobes are the contact points, rather than two points directly across from each other. That can be important for applications where the cylinder is at rest for some time and/or moves very slowly.

The rotary manifold seals just seemed old, the O-ring took a permanent set and no longer held pressure. The local people think the little grooves in the x-rings will hold a little oil and make the rings last longer due to better lubrication. Both of these applications are slow rotation seals, the rotary manifold one rarely sees a full revolution.

If compression set was the primary failure mode, there was likely not a major issue with insufficient lubrication anyway. It sounds like you will probably get several thousand hours' worth of reliable service with either new o-rings or the quad rings. One way the quads might outlast the o-rings would be that the four lobes "bend" outward rather than straight compression. This can reduce the internal stress on the material and can slow down the compression set.

Thanks BCPete, That makes a lot of sense. The locals like them because they act like there are two o-rings next to each other so more chance to stop oil from leaking.

Whatever you use make sure there's no chemical compatibility issues. If the fluids in the system attack the polymers in the seals you'll have to deal with that. Many more materials choices in O-rings than for Quad rings.

Or go for Kalrez o-rings. The only thing they cause to fail is your heart when you find out how much they cost...