O-ring squeeze verses pressure data 1

[DustinMechEng]

I am looking for data regarding maximum fluid pressure verses o-ring squeeze. I am designing an o-ring face seal and would like to know what maximum pressures the seal could hold at different amounts of squeeze. Thanks in advance for the help!

 

[MikeHalloran]

Use the groove dimensions, finishes, and tolerances in the Parker catalog. Do not waste your money trying to do better; you can't.


Pressure capability doesn't come from squeeze, it comes from lack of gaps/ clearances, which are determined by tolerances, or occluded by back-up rings. Read up on those.





Mike Halloran
Pembroke Pines, FL, USA

 

[EdDanzer]

Actually the Parker groove data is not good for cyclic high pressure applications. The wide groove allows too much movement of the ring. In cyclic pressures over a few thousand psi it is better to use a square or quad ring and only use enough squeeze to hold low pressure sealing. Limit the groove width to as narrow as possible to allow installation and removal. In our Hydraulic cylinders that see 15,000 psi pressure spikes I use a 90%+ groove fill to limit explosive decompression.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com

 

[monkeydog]

Ed,
What do you mean by "+ groove fill"?
Are you talking about the minute gaps between the groove corner and your seal corner?

 

[israelkk]

"groove fill = ( O-ring cross section area / grove cross section area ) x 100

 

[DustinMechEng]

Thanks for the responses. Unfortunately, due to friction constraints, I can't design the gland at the parker recommended squeeze. We have to use considerably less squeeze. So far, we have used an experimental approach of finding the least amount of squeeze that holds the system pressure (fairly low ~ 20psi). I was just hoping that maybe someone had published some research or analytical results on squeeze verses pressure for a face seal.

 

[EdDanzer]

Are you sliding the seal across a surface that you are trying to seal?

When describing your problem more detail is very helpful.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com

 

[DustinMechEng]

It is a face seal that gets slowly rotated. Imagine a cylinder with a hole through its center. Now the end of the cylinder is pushed up against a flat plate with a hole through its center. Fluid (water) must pass through both the cylinder and plate, so a face seal on the end of the cylinder is created with an o-ring. The cylinder slowly rotates.

 

[RSS22]

Is friction the problem? Have you tried a dry-film lubricant on the seal?

Ron Dunn

http://www.rubbersurfacesolutions.com

 

[MikeHalloran]

For low friction try a V-Ring seal.



Mike Halloran
Pembroke Pines, FL, USA

 

[EdDanzer]

The initial compression of the sealing material just needs to exceed the fluid pressure. This means that when the seal is deformed from pressure that the contact area has a pressure greater than the fluid pressure. Variations in seal hardness can affect the compression pressure which will change the friction.

Ed Danzer

http://www.danzcoinc.com

http://www.dehyds.com