high pressure seal

[1chilleng2]

Hi,

I have a case with a rotating piston and a cover, there is oil inside the case. Right now I am using o-rings but the device is leaking. The problem is that when the piston moves the pressure can reach 10000psi. I've looked into o-rings with backups but the backups seem to go on the top and bottom of the o-ring rather than on the inner and outer diameter of it. So I'm looking for some seals, one on one side of the rotating piston, two of the other side and then one between the case and cover. The problem that I have is that I'm not really sure where to look for the seals because they aren't the typical piston or rod applications. Does anyone know if the rod seals will work for this application? Are there any good resources that would help me out?

Thanks for any help that you can provide.

 

[EdDanzer]

What is the surface speed and material rotating against the seal?
Sealing 10,000 psi is tough. O-rings are a poor choice as they become almost square in the groove. Very few materials can handle much speed at 10,000 psi. A seal is a bearing running dry at the actual point of sealing.

 

[martintw]

Sounds like you need an energised seal (spring-loaded lip seal)or one of the other specialised seals. It is common at these pressures ( and higher pressures) to use special metallic seals with an elastomeric backup. If the seal diameter is large or temperatures are involved you must take account of the differential expansion across diameter and the seal will be designed to accommodate this. Be sure to ensure there is no galling on metal to metal sealing arrangements. You probably need to talk to some one like James Walker (

http://www.jameswalker

.co.uk) who do a lot of seals at 10 k . There is another company, I think it is called Gulf Sealing, who also do a lot in the 10K - 20 k areas.I can find out their name but do not have it to hand.

Good luck.