Biogas Safety first!

Specific requirements
The location of gas lines laid below ground must be
identified by gas pipeline warning tape. The suitability
of flexible gas-carrying connecting pieces belonging
to the CHP unit and the component parts of the
charge-air cooling system must be certified by the
manufacturer of the CHP unit.
Connection points in gas lines for non-stationary
facilities, such as mobile gas flares, must be fitted
with isolation valves. The shut-off valve must
be installed upstream of the non-stationary facility,
viewed in the direction of gas flow. It must be possible
to operate it safely.
Classification of Ex zones
Gas-carrying pipes
Pipes carrying biogas (technically leak-tight);
periodic inspection of plant parts for leaks.
Same zone as connected plant parts.
Pipes carrying biogas (technically leak-tight);
periodic inspection of plant parts for leaks, but
a potentially explosive atmosphere may occur
in connected plant parts. The penetration of
potentially explosive atmospheres into the pipes
is prevented by automatic isolation from the connected
gas system.
Same zone as connected plant parts.
10. Requirements for condensate traps
Technical protective measures
It must be possible to inspect and maintain condensate
traps easily and safely, without having to climb
into shafts or pits. Permanently attached climbing
irons are not permissible unless the shaft of the
condensate trap has forced-air ventilation. Furthermore,
access to these shafts is only permissible after
clearance measurement.
The design of the trap and maintenance measures
must ensure that the escape of gas is prevented in all
operating states. Condensate discharge pipes must
be designed to be frost-proof and operational at all
times.
Pressurised seal systems must be designed such
that the sealing liquid is unable to escape when the
system is triggered but instead flows back automatically.
The filling level of the liquid seal corresponds
at least to a pressure of 15 hPa (150 mm water
column or 15 mbar) above the maximum response
pressure of safety devices and is monitored using
measuring instrumentation.
In inside spaces
Classification of Ex zones
Gas escape is prevented by the use of closed
drainage systems, e.g. locks with interlocked
double-shut-off valves; spaces with natural
ventilation.
No zone necessary.
If drain cocks are present, or open water seals,
it must be expected that a hazardous explosive
atmosphere will be formed as a consequence of
the water seals being punctured or drying out, or
because of an operating error. Discharge to enclosed
spaces; space with technical ventilation.
Zone 2: entire space
If drain cocks are present, or open water seals,
it must be expected that a hazardous explosive
atmosphere will be formed as a consequence of
the water seals being punctured or drying out,
or because of an operating error. Discharge to
enclosed spaces; space with natural ventilation.
Zone 1: entire space
Zone 2: 1 m around openings in closed space
Organisational protective measures
Requirements applicable to lone working must be
taken into consideration (see section on protective
measures).
Outdoors
Drain cocks outdoors, or pipes from condensate
separators installed indoors ending outdoors.
Zone 1: 1 m around the outlet nozzle
Zone 2: a further 2 m around the outlet nozzle
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