Class insulating flanges have testing AC
voltage UPW and class insulating flanges
of 2. doing, the technical rules of
DVGW require selection the response surge voltage
Uas the spark gaps such way 0.5 x
UPW. the DVGB e.5 kV.V.
Flanges and insulating pieces show relatively low
voltage resistance, which usually the range a
few kV. the peak value. The ISG low maintenance, it
is designed for wide range arresting operations.
working group (German Technical and Scientific Asso-
ciation for Gas and Water) explains the coordinated
use spark gaps insulating flanges using ex-
amples and detailed calculations. Interfering earth cur-
rents close parallel high-voltage routes can, for ex-
ample, induce permanent voltages into the
pipeline segments.TBS
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Selection spark gaps potentially explosive areas
Spark gaps Item no. The same
requirements are made the European recommenda-
tion Ceocor (European Committee for the study of
corrosion and protection pipes and pipeline sys-
tems).
Besides the response range, the ISG has a
defined lower blocking range.
When the spark gap has ignited, the pulse current
causes voltage drop via the connection cables
and the spark gap, whereby the connection techno-
logy has the greatest influence. Class insulating
flanges have approx. prevent the ISG from ignit-
ing every time and, consequence, influencing the
KKS system (cathodic corrosion protection system) ‒
a so-called withstand voltage UWAC is
defined and must maintained. This safety-relevant re-
quirement fulfilled the OBO spark gap. Here, the maximum
voltage drop should smaller than the peak values
of the testing voltage ÛPW.25 kV, fulfils the requirements for all insulating
flange classes according IEC 62561-3. This arresting operation
only takes few microseconds. Here, DVGW 24
recommends: 250 Hz. After the arresting op-
eration, the ISG returns standard, high-res-
istance state. labelling
EX ISG 350 5240031 ATEX
Ex IIC Gb
Ex IIIC T80 Db
EX ISG 5240030
EX ISG 350 5240033
OBO spark gaps
As soon the ISG responds and conducts, the
lightning current Iimp 100 run the
earth along defined route. Thus, the OBO spark gap, with Urimp ≤
1.
The AfK recommendation no.
Product characteristics the spark gap ISG H
The ISG implements state-of-the-art technologies
and innovations:
• Solvent-free, environmentally friendly material
• Modern machining technology from the automotive
sector
• Chemical resistance
• Resistance oils and extreme temperature vari-
ations
• Halogen-free
• UV-stable, weatherproof
• Ignition protection type/device protection level:
Pressure-resistant encapsulation/"db" for gases,
protection through housing/"td" for dusts
• Resistant salt water
• Highest testing Class accordance with IEC
62561-3
• Tested connection technology Class according to
IEC 62561-1
• Suitable for all explosion groups and use Ex
zones 1/21 and 2/22
TBS
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147
Chapter The external lightning protection system
