O-rings dynamic flange application

We have an article on static O-rings in a flange arrangement
[URL]https://www.engineersedge.com/general_engineering/oring_gland_size_static_flange.htm[/URL]

And dynamic O-rings in a reciprocating cylinder arrangement
[URL]https://www.engineersedge.com/general_engineering/oring_gland_size_dynamic_cylinder.htm[/URL]

But what does an engineer use in a dynamic flange arrangement? For example, if in the first article, the two flanges were to rotate with respect to each other. Or is there a good reason that this is a very bad idea and I need to redesign things to make it look like the second article? Do just give a little more depth so the compression is only 10-30%? I'm making a high pressure air swivel joint.

Regards,

Harry R. Burger
Mechanical Engineer
CSWP

Static means that the two flanges are to not move relative to one another. Dynamic means movement and the o-rings are compressed less to allow movement and less friction. For rotation use the dynamic design.

I may be wrong but I think most if not all of the dynamic seals in standard commercial rotary unions are of the cylindrical type. Have you contacted some of those manufacturers? There's a lot of expertise there, and some of them have probably already done what you're trying to do.