Optics Housing Side Purging; Process Side Purging - Siemens LDS 6 Compact Operating Instructions

5.2

Optics housing side purging

NOTICE
Failure of purging gas supply
When the process purging is connected to the optics housing purging, it may be necessary to
use non-return valves to ensure that no process gas can enter the purging gas line in the event
of failure of the purging gas supply. This applies especially in the case of cascaded optics
housing and process purging where there is otherwise the danger that, for example, corrosive
process gases could enter the optics housing.
5.3

Process side purging

With this option a needle valve is supplied with the analyzer which must be mounted on the
process interface.
Damage due to overpressure
Observe that the use of this needle valve opens up into the process. The process must be
permanently monitored if it is under pressure. If any danger for personnel or equipment can
arise from the over pressurized process we recommend to mount a check valve on the process
interface to prevent flow out from the process.
Make sure that under no circumstances the process gas will intrude into the purging system.
This applies particularly to a cascaded optics housing and process purging which otherwise
may lead to ingress of corrosive process gases.
NOTICE
Damage to the optics
Always install the purging system before you install the optics housings to avoid damage to the
optics during the rest of the installation process. For optimal results use optics housings
equipped for the specific purging type, supplied by Siemens AG.
Ex zone entrainment
It is in the responsibility of the customer to implement a safety concept that ensures that Ex
zone entrainment cannot occur when using process purging. A possible solution may be the
use of non-return valves in the process purging gas flow to ensure that no gas can leave the
process through the purging gas connection.
LDS 6 & Optics housing CD 6 Compact Operating Instructions
Compact Operating Instructions, 12/2022, A5E03314905-AB
WARNING
WARNING
Commissioning
5.3 Process side purging
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