Endress+Hauser SpectraSensors SS2100i-1, Обзорное руководство

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Sample Conditioning System
SCS Overview Manual 3
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11
4. Close the bypass supply shut-off valve. Refer to the analyzer system
drawings.
To isolate the SCS for short‐term shutdown
The SCS can be isolated from the process sample tap for short-term shutdown
or maintenance of the SCS without requiring the shutdown of the field pressure
reducing station.
1. Isolate the analyzer from the bypass following the procedure under
“To isolate the measurement sample cell for short-term
shutdown” on page 3-10.
2. Close the sample supply shut-off valve to the SCS.
3. Allow the sample bypass to flow until all residual gas has dissipated
from the sample transport lines as indicated by no flow on the
sample bypass flow meter.
4. Close the low pressure flare or atmospheric vent header shut-off
valve for the effluent from the sample bypass.
5. Turn off power to the analyzer.
If the system will not be out of service for an extended period, it
is advised that power remain applied to the sample transport line
electric tracer, if applicable, and the sample system enclosure
heater.
Process samples may contain hazardous material in potentially
flammable and/or toxic concentrations. Personnel should have a
thorough knowledge and understanding of the physical properties
and safety precautions for the sample contents before operating
the SCS.
Although the pressure reducing regulator at the process sample
tap is designed for “bubble-tight” shut off, this condition may not
occur after the system has been in operation for an extended
period. Isolation of the SCS from the field pressure regulator will
discontinue sample flow and may cause the pressure at the outlet
of the field pressure regulator to slowly increase if “bubble-tight”
shut off of the pressure regulator does not occur. The slow
pressure increase will continue until the pressure setpoint of the
relief valve is reached and the excess pressure is vented by the
relief valve. To prevent this, isolate the sample at the probe or
vent the sample to a safe location.
If the system will not be out of service for an extended period, it
is advised that power remain applied to the sample transport line
electric tracer, if applicable, and the sample system enclosure
heater.