<VV> Re: Leakdown Test - Yes, but some words of wisdom

[VairMech@aol.com]

In a message dated 4/6/2004 3:39:00 PM Eastern Standard Time, 
burkhard@rochester.rr.com writes:
The "% leakdown" number they give is a just a ratio of pressure drops with 
respect to a PURELY ARBITRARY reference orifice in the tester. There is no 
standard for this orifice's effective flow area, so different brands of testers 
will give completely different leakdown numbers on the same cylinder!  Thus, you 
CANNOT just pull an absolute number out of the air and say "less than 5, 10, 
or X% leakage is OK". It all depends on the tester itself. 
>>>>>>>>>>>>>>>
    If I recall corectly the oriface size for aircraft testers is .060" and 
you use 75% @ 80 psi. as the number where something needs to be corrected. So 
there is a standard, it just isn't used in the auto industry.
    Ken Hand