GTA
All Springer/NP/PCP Air Gun Discussion General => Machine Shop Talk & AG Parts Machining => Topic started by: Ronno6 on January 04, 2025, 10:09:10 PM
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Not sure exactly where to post this.....
Is there a difference with regard to pressure holding capabilities of O-rings of different cross sections?
For a given OD, will fatter CS O-rings handle more or less pressure than thinner CS O-rings??
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You can buy a roll of any cross section o-ring material to make an o-ring of any diameter. The variations in cross sections might be for fitment rather than pressure?
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It's a package design question.
Gap dimensions, crush, and durometer (ShoreA Hardness, 70A, 90A, etc.) are all important factors.
A thicker o-ring "might" seal better with sloppy fit tolerances OR a thicker o-ring "might" leak sooner because sealing force is spread over a larger area.
A softer o-ring might seal better under low pressure applications but it might extrude like putty under higher pressures.
If the application is not static (a sliding piston-ring application) a thinner+harder o-ring might have less friction loss.
Many factors to consider. Not one simple answer like "thicker is always better" :-)
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I'm sure there are more compact sources, but I've used this guide to help. https://www.parker.com/literature/O-Ring%20Division%20Literature/ORD%205700%20Parker_O-Ring_Handbook.pdf Lots of data there - probably more than you ever wanted to know.