O-Ring Compression Force

I appreciate the response, but doing an FEA run to get results is like using a sledgehammer to put a tack in corkboard. All I need is a simple equation that lets me plug in material and size coefficients that will give me a force/length number. Something I can put in a spreadsheet that will let me play with different numbers and give me instantaneous results. You seem to be familiar with the equations. I haven't had Mechanics of Materials and don't quite know the right equation to use. Could you share the equation you're using or point me to a source for it?

I derived the equation from Parker's data. It is as simple as that. Today when almost everybody has a FEA soft (even I as a simple expert/consultant am equiped with ALGOR) it is not any more a too complex acces as before. You can derive the equation considering that the o-ring maintains its section area when deformed which gives you the width of the flat contacts with the groove walls and you replace the half circles with a traingle 2 on each side. The model is simple, not very precise but gives enough precision. I am sorry but I have nothing more than the graph the rest went lost when moving. In fact as far as I remeber the problem was to determine from available data the E value for every Shore Hardness.

With respect to the equation it is a complex problem this is the reason I used experimental data since it is a non linear section and deformations are important and the stuff is non linear so evry thing one can find to get headaches.

How about empirical? If you have access to a machine shop make a .060 groove in a block of wood, aluminum, plastic etc. Lay an O Ring in the groove set the whole thing on a bathroom type scale. Force a 1" wide flat hard object down until it compresses the O-Ring (.010) enough to make full contact. Have an associate test your compression by pulling a piece of paper out from both ends. When the paper is snug read the scale. Multiply this force by 6 for 6 inches.

If you don't have machine shop capability lay pieces of shim stock, etc in parallel stacks for a .060 depth and compress an inch long length, same as above.

O Rings of the same dimension are made of different materials with different durometers so a formula might be inaccurate.

what is the durometer of the o-ring?.....70 maybe?

You may go through following:

http://www.google.co.in/search?hl=en&q=parker+o+ring+calculator&meta=&aq=8&oq=Parker+O+

Besides they have design software available on their site, which is downloadable.