gland design and oring selection for high pressure and high temp
gland design and oring selection for high pressure and high temp
(OP)
Hi fellow engineers,
I'm designing a tool that will be in an environment of 15000 - 20000 psi and a temp of 450F. So far I've looked at some examples and done some research about the size and shape of the gland, clearance and materials for the o-rings, but I still have a few questions:
Right now I'm debating whether to use AS568-2XX or AS568-3XX o-rings.
If I use 2xx o-rings, they will be 3 consecutive and if I use 3xx, I'll use only 2 due to space restrictions.
Can anyone tell me the difference between using o-rings with a smaller or larger cross section?
I assume bigger o-rings will be more resistant and will provide a better sealing in extreme environments, but I'm still curious.
Thank you.
I'm designing a tool that will be in an environment of 15000 - 20000 psi and a temp of 450F. So far I've looked at some examples and done some research about the size and shape of the gland, clearance and materials for the o-rings, but I still have a few questions:
Right now I'm debating whether to use AS568-2XX or AS568-3XX o-rings.
If I use 2xx o-rings, they will be 3 consecutive and if I use 3xx, I'll use only 2 due to space restrictions.
Can anyone tell me the difference between using o-rings with a smaller or larger cross section?
I assume bigger o-rings will be more resistant and will provide a better sealing in extreme environments, but I'm still curious.
Thank you.





RE: gland design and oring selection for high pressure and high temp
O-ring catalogs usually do not give information for pressures so high, how did you researched about size and shape of glands?
RE: gland design and oring selection for high pressure and high temp
The round ring will become almost square causing wear to the gland and the o-ring when going from 0 to 20,000 psi. Few elastomeric materials will handle 20,000 psi at 450°F. Size is relative and since you did not provide any details about the application no suggestions can be made.
Ed Danzer
www.danzcoinc.com
www.dehyds.com
RE: gland design and oring selection for high pressure and high temp
The application will be static and the type of sealing is radial. The material for the housing is steel and its finish is smooth.
The idea is to prevent leakage (it is a logging tool, so no mud/sand/dirt and water must come in).
I,ve seen other logging tools and also found information about gland design; that was for more normal pressures, but the dimensions were very close to those found in other tools.
I'm planning to use backup rings as well.
RE: gland design and oring selection for high pressure and high temp
RE: gland design and oring selection for high pressure and high temp
The "best" O-ring materials for petroleums don't really take that temperature well, and if any gases are present, you can have trouble with explosive decompression when the tool is pulled back up (gas dissolves into the rubber at pressure, esp. CO2, then comes back in a hurry when the pressure is relieved, rupturing the seal material).
RE: gland design and oring selection for high pressure and high temp
Does it have to be an O ring or an elastomer type seal ?
Have you considered spiral wound gaskets ?
The conditions you specified are pretty extreme for any O ring type seal
RE: gland design and oring selection for high pressure and high temp
With radial spring energized PTFE for rotary you have to select a spring with a very flat spring constant or you will have seal failure rather promptly.
Recommend something like this or equivalent: http://bit.ly/4qypIB
RE: gland design and oring selection for high pressure and high temp
You are going to require a high filled PTFE Variseal PTFE spring energized seal c/w PEEK back-ups or equivalent. Moveover request to have seal contact surface come complete with point loads so that force is acting on points for contact and not across entire seal footprint.
RE: gland design and oring selection for high pressure and high temp
Scott N.
Ex-Verto Engineering
www.ex-verto.com
RE: gland design and oring selection for high pressure and high temp
RE: gland design and oring selection for high pressure and high temp
When you give this temperature and pressure, how much safety has already been added to this? I find that stories quickly change when people find out how much it costs to have a wide safety margin. (Recommendations usually have a margin built-in anyway.)