GASKET LEAKAGE
GASKET LEAKAGE
(OP)
IF A GASKET IN NEVER PERFECTLY TIGHT, HOW COME WE HAVE NO LIQUID LEAKAGE OR TOXIC GAS LEAKAGE?
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RE: GASKET LEAKAGE
Anyway a possible solution is to use double gaskets, venting the space between the gaskets to a suitable treatment plant.
prex
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RE: GASKET LEAKAGE
Leaks occur or do not occur for a huge variety of reasons. If your gasket/seal ring/rtj etc. is not perfect and you have no leak it may just be that the potential leak path is too small to allow a leak (smaller than the particle size of your content).
If leakage or potential leakage is a problem there are various methods of leak detection prior to service.
RE: GASKET LEAKAGE
Please lose the all caps key, it is the equivalent of shouting.
Crashj
RE: GASKET LEAKAGE
RE: GASKET LEAKAGE
1. Laboratory - Specs we all use M and Y factors etc,API etc
2. Field experience, having just finished a flange
monitoring program, flange leakage is uncommon
especially if you measure against EPA standards ie PPM
So a "leak" or tightness depends on your point of view
Mike
RE: GASKET LEAKAGE
Nowhere in that definition (which is what is used for automotive powertrain) is the implication of infinite gasket stress; rather the implication is non-zero gasket stress.
If you don't agree with my assessment; please clarify your statement. I know that this is the way that it is done, but I am not completely attuned to some of your terms. For that reason, I may be misinterpreting what you are stating.
Regards,
Brad
RE: GASKET LEAKAGE
http://www.meca.polymtl.ca/TTRL/tests/tests_list.html
Since the tightness parameter is meaured using a helium mass spectrometer to measure leakage of helium at eigher 400 or 800 PSIG, this is why there is no such thing as a "leak proof" gasket. Helium is notoriously difficult to seal, and the mass spectrometer can measure leakage as small as 10^-9 cm^3/s.
RE: GASKET LEAKAGE
After reading it, I am not clear what specific gasket applications they are testing for.
My more educated response to the original question would be that these tests are certainly worst-case--many gaskets operate in much lower differential-pressure environments. Also, they are required to hold materials which have significantly larger molecular size than helium.
Other than hydrogen, I would expect that no molecule would elicit greater 'porosity' across a gasket than helium. Since this test is essentially worst-case, wouldn't it be logical that a 'fail' under these conditions may still be effectively leak-proof for many applications?
Therefore, a seal which is not 'perfectly tight' by this standard may be in fact leak-proof for in-service conditions.
My two cents.
Brad
RE: GASKET LEAKAGE
Can some one suggest a book for studying leak science which gives various parameters for seal technology.
RE: GASKET LEAKAGE
Brad