Leak Testing: Useful leak specification guidelines

Product/Component Test Pressure Leak Test Method
WATER LEAKS/COOLING SYSTEMS 1 to 2 bar 4 to 7 cc/min Air pressure decay
OIL LEAKAGE (various) 0.1 to 7 bar 6 to 15cc/min Air pressure decay/flow
FUEL/DIESEL 1 to 10 bar 0.1 to 15cc/min Air pressure decay
FUEL/PETROL 1 to 5 bar 3.0 to 15cc/min AirPressure decay
REFRIGERATION/AIR CONDITIONING 2 to 20 bar 5 to 15 gm/yr Tracer gas
ELECTRICAL HOUSING/CONNECTORS 0.1 to 1 bar 0.01 to 1cc/min Pressure decay/Tracer

Bubbles to leak conversion

cc/sec (ml/sec) mm3/sec cc/min (ml/min) 1 cc (1 ml) 2mm bubble
0.1 100 6 10 sec 24 bubbles per sec
0.01 10 0.6 100 sec 2 bubbles per sec
0.001 1 0.06 16.7 min 4.2 secs
1x10-4 0.1 0.006 2.8 hours 41.9 secs
1x10-5 0.01 6x10-4 27.8 hours 7.0 min
1x10-6 0.001 6x10-5 11.6 days 69.8 min
1x10-7 1x10-4 6x10-6 16.5 weeks 11.6 hours
1x10-8 1x10-5 6x10-7 3.2 years 4.8 days
1x10-9 1x10-6 6x10-8 31.8 years 6.9 weeks
1x10-10 1x10-7 6x10-9 318 years 1.33 years

Pressure conversion chart

To convert from to (multiply by) bar psi kPa kg/cm2 mbar Pa inH20 mmHg
bar 1 14.5 100 1.02 1000 100000 401 750
psi 0.069 1 6.9 0.07 68.97 6896.55 27.66 51.72
kPa 0.01 0.145 1 0.01 10 1000 4 7.5
kg/cm2 0.981 14.23 98.14 1 981.35 98135 393.52 736
mbar 0.001 0.015 0.1 0.001 1 100 0.4 0.75
Pa 1E-05 1.4E-04 0.001 1.02E-05 0.01 1 0.004 0.0075
in H2O 0.0025 0.036 0.249 0.0025 2.49 249.38 1 1.87
mm Hg 0.0013 0.019 0.133 0.0014 1.33 133.33 0.535 1

Leakage flow rates conversion chart

To convert from ….to (multiply by) atmcc/sec m bar.l/sec atm

mm3/sec

atmcc/min atmLitre/min atm

m3/min

atmcu ft/yr torr.l/sec
atm cc/sec 1 1.013 1000 60 0.06 6E-05 1116 0.759
mbar.l/sec 0.987 1 987 59.23 0.059 5.9E-05 1101 0.75
atm mm3/sec 0.001 0.001 1 0.06 6E-05 6E-08 1.116 0.0007
atm cc/min 0.0167 0.017 16.67 1 0.001 1E-06 18.6 0.012
litre/min 16.67 16.88 16667 1000 1 0.001 18601 12.67
atm m3/min 16667 16883 16666667 1000000 1000 1 18601190 12664
cu ft/yr 0.0009 0.0009 0.896 0.054 5.37E-05 5.37E-08 1 0.0007
torr.l/sec 1.316 1.33 1316 78.96 0.0789 7.89E-05 1468 1

To find out more about how we can help you with your leak testing requirements:

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Get in touch with us to discuss your requirements and we will be happy to offer our professional advice and visit you at your site.

TQC Ltd, Hooton Street, Carlton Road, Nottingham, NG3 2NJ, United Kingdom
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