I always miss the good arguments.... FYI I am a flange gasket expert, I've seen and tested every conceivable way to apply load to a gasket..
Franky r6155 is right, but so is XL83NA etc... hence why the PCC-1 allows for torque control of flanged joints. In a perfect world all the joints would be...
No crushing the gasket is a big concern here (especially soft materials), because now your now setting gasket stress to 100% of what it was at the install torque but your gasket material is now at 400F... and that is not the same as if it was at room temperature. As you say bolts lose some force...
Leakage has two components, permeability through the material and surface leakage through the interface.
When both at full density i.e. well-compressed the permeability through the materials (PTFE vs ePTFE) is basically the same.
However, when creating the seal the ePTFE is more conformable so...
So this is the plan, I'll add an sized blow out disc that blows out at say 2x more than the valve (Bout). (if i can find one that is ok for vacuum and pressure ??)
V1 should 90% of the time not fail, and if it does it'll likely be a whimper and not a boom 90+% of the time. But as littleinch...
Hi all I am looking at building a testing device. See simple image.
To measure leakage of helium from a test device with internal volume (V1) upto 200 bar with helium. (no explodey gases)
I want to use use our Helium Mass Spectrometer (HeMS) in full vacuum mode so I'd like a vacuum chamber...
Now accurate do you need this? Also what pressures/dT ... will everything remain gaseous ?
Atmospheric air ?? Where and when did you sample it ? Any water content of the air ? Pollutants ? Pollen ?
Heat absorption/dissipation with the larger areas on the big volume....
Adsorption rate of the...
a volumetric, pressure change per unit time vs a a gravimetric, weight change per unit time.
With the gravimetric you can get an actual amount of product/material being lost directly from the leak.
With the volumetric you cannot unless you know the actual volume of the pressurized system to a...
By hot torquring do you mean torquing the bolts when they are above 400F ?
or do you mean re-torquing the bolts again while at room temperature but after they have seen 400F+ (retorque after a heat cycle)
Be very careful if its while at heat, as over crushing the gasket is easily done here and...
If you are asking, can I make this very important repair to basically the weakest part of a pressure vessel without having to do the proper checks afterwards... then I think you already know the answer.
ePTFE is porous when uncompressed, apply several tonnes of force in a flange and it is no longer porous so gets to the same density as virgin PTFE, yet has more strength from the now much more structured material. The compression of ePTFE is no way linear, they compress very easily and become...
@r6155
As with my first reply to the user of this custom flange they should contact somebody to evaluate it correctly and not estimate anything. A flange this size with these pressures is no joke. However, I can tell you for sure that I wouldn't start shouting about RTJ gaskets without knowing...
You can also get lower stress to seal spiral wound gaskets. Lemons, Flexitallic Garlock etc all supply these.
Manway gaskets have many options... I fail to understand why the Steel-Trap (TM) [available only from Chesterton] is the only option available....I'd perhaps ask a more independent...
Do not reuse an RTJ even if somebody says you can, seriously man gaskets cost nothing buy a new one every year.
Also I am camp Kammprofile, RTJ's need to go.
FYI - You can also get kamm'ed and faced RTJ's or Flexitallics Change gasket is also great.
Also the API hasn't known what it is doing...
I wish I read your thread here before replying to your other one and told you what you knew already... I regret nothing!
The metal core here really only aids blow out from over pressures and 100 psi is frankly nothing.. so a blow out is really only going to occur with loss of load so creep...
Generally, they are frankly a bit of an oversell, a decent sheet PTFE is 99 times out of 100 more than adequate for blow out resistance. However if creep resistance and blow out resistance are your bugbear then perhaps check out expanded PTFE sheets like Gore GR, Teadits 24SH or even Durlons own...
m and y values... *Shakes head and laughs in European*
Firstly, do you know how to calculate and install a gasket correctly as per ASME PCC-1 or EN-1591, if not call a consultant because at 178bar you are basically making a bomb.
I assume this is a steel vessel of some sort and not something...
If your doing it purely via pressure drop of the system.. gases are harder to seal than liquids so your drop in pressure will be quicker with a gas vs a liquid. However there isn't any rule of thumb for how much quicker as it depends on a lot of things.
I should also add here, liquid pressure...
Also while you are looking at that, check out Flexitallics Change gasket, its sort of a best of both worlds. Basically a spiral wound gasket with extra thick windings that don't buckle as easily and impart more resilience. They are really good... but I am slightly biased because I did a large...
