Material Creep vs. Compression Set

[Jimmo]

I have an application where I am tryin to seal (static) internal combustion exhaust and I am currently using a 75 durometer FKM component similiar in shape to a compression seal used in plumbing applications. I am worried about creep in this application. My vendor has recommended moving to a 90 durometer FKM, which has a slightly higher compression set than the 75 durometer material.

My questions
- is there a correlation between creep and compression set?
- should I be concerned about creep?

 

[prodeng]

One thing I recently learned about rubbers is that the modulus in a case like this is probably more important than the durometer. The two usually follow each other, but that is not always the case. O-rings (I'm assuming used here) usually follow durometer ratings, but a rubber manufacturer can give you the current modulus and possibly vary that to help you avoid a problem.

One other thing: anywhere you have compressed rubber, you have a permanent compression set. You can minimize it with certain materials (like black EPDM vs. Buna N), but it will probably need replaced eventually.

 

[pairoch]

Sir,

I don't think same with your vendor,More hardness of o-ring that means less elasticity you have.

Bye.

pairoch@ascthai.com