Leakage Formulas

LEAK RATES

std cc/sec approx. = approx. bubble equivalent

10-1 = 1 cc/10 sec
10-2 = 1 cc/100 sec
10-3 = 1 cc/hour
10-4 = 1 cc/3 hours
10-5 = 1 cc in 24 hours
10-6 = 1 cc/2 weeks
10-7 = 3 cc/year
10-8 = 1 cc/3 years
10-9 = 1 cc/30 years
10-11 = 1 cc/3000 years

*Note : Experimental data indicate that no visable water will leak when dry air, at the same pressure, will leak at a rate as great as 1 x 10-4 cc/sec. To be on the safe side, it is believed that enclosures which are to contain liquids, such as water or oil, should have no leaks at rated pressure which are larger than 1 x 10-5 standard cc of air per sec. Helium leakage in volume is about the same as air and refrigerant- 12 for leaks of approximately 1 x 10-6 standard cc/sec. For leaks smaller than 1 x 10-6, the volume of helium leakage will be somewhat greater than air through the same physical leak at the same pressure difference.

LEAK CONVERSION TABLE

Horizontal Lines Represent Equal Leake Rate Values

*For air in water, bubble diameter approximately 1mm

LEAK RATE CONVERSION CHART