ABB EL3000 Series - Important Notes for Flammable Gas Versions

120 EL3000 CONTINUOUS GAS ANALYZERS | CI/EL3000-EN REV. B
Important note for the gas analyzer version for measurement of
flammable gases
Measures taken after opening the gas paths inside the gas analyzer
 If the sample gas feed path inside the gas analyzer has been opened, the
seal integrity should be tested with helium at a leak rate of
< 2  10
−4
hPa l/s.
 The pressure drop method (see page 119) can be used as an alternative
to the helium test. To accomplish this, increase the test pressure to a p
e
of approx. 400 hPa (= 400 mbar) and increase the test period to
15 minutes. The maximum excess pressure p
e
= 500 hPa (= 500 mbar).
 Any time the gas path is opened it must then be purged prior to con-
necting the power supply. This should remove any explosive gas/air
mixture in the gas path.
 Purge gas: Inert gas
 Purge gas quantity: 5 times the volume of the gas paths
 Purge gas flow: Approx. 30 liters/hour
 Purge duration: At least 3 minutes
The purge gas should not contain any sample gas components.