Hydraulic Seals @ 25,000+ psi?

[BasketDaN]

I'm unable to find a hydraulic seal with a maximum operating pressure any greater than 11,000 psi, and that was a specific type of "vee packing." Does anybody know of a type of seal that can withstand more?

[Bystander]

http://www.globalspec.com/industrial-directory/metal_o-rings?se=ink&setag=INDIR

These are static seals.

You want a moving seal, HIP's chevron packings (screw pumps) will go to 30k --- if you're very, very careful, extremely fussy during assembly, and willing to replace the packing on a regular basis. Ruska, D&H, and a couple other instrument makers offer high-P screw pumps as well. It's a stretch to call any of them "sealed" --- there is slow bleeding, creeping of cylinder and piston (bulk failure), and thermal expansion/contraction of fluid --- bottom line? Tough to set a pressure on a system and have it stay put without positive shut off valves.

[BasketDaN]

Thanks a lot, I'm not really sure of what I need here, but I don't think it's a non-static seal... I need a metal bar to be able to slide out of a container with very high pressures inside it, and I'm assuming I need a non-static seal around this bar, correct?

[brewnog]

Yep, that's the one. Chevron Packings are the way.

[Bystander]

Axial movement is a moving seal. This pressure range is NOT recommended for OJT --- finishes on surfaces are critical, control of off-axis loads to "zero" is non-trivial, and the available "PV" work for "non-compressible" fluids is more than adequate to do serious injury. You might consider turning your "high pressure ram" specs over to customer service or engineering support at Aminco, HIP, Parr, or some other high pressure instrument/bomb company.

[Bystander]

Oh-ho! An "ice dilatometer!" Anything specific you're trying to determine?