Yokogawa In-Situ Gas Analyzer TDLS200 - Manual (Page 131)

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IM 11Y01B01-01E-A 6th Edition :Feb 13, 2013-00
<9. TROUBLE SHOOTING>
lf possible to isolate the process flow through the measurement section of the process pipe/stack then
proceed to shut it off accordingly to facilitate full, safe unrestricted access.
c. If the process gas cannot be isolated (as is typically the case), then “Process Inspection Port” must be
used (see below/next page). These essentially replace the analyzer units (launch and/or detect) while
maintaining the process window purge integrity to allow for visual inspection of the active process
conditions. Note: The rating is the same as for the standard analyzer, max 5.5 Barg (80psig) and for gas
temperatures above 50˚C (120˚F) window purge gas must be flowing.
d. To inspect the launch unit nozzle, first the process isolation valve has to be closed carefully while
coordinating the shut-off of window purge gas flow. If the process is operating at negative pressure and
the ingress of ambient oxygen is not desirable then the nitrogen purge gas must be maintained as the
process valve is closed off. Once closed, the nitrogen purge gas can be shut-off and then carefully
relieved from the section between valve and window (typically loosen a tube fitting).
e. Once the process valve is closed and window purge gas shut-off (and pressure relieved), then the launch
unit can be removed from the alignment flange. Remove the Allen screw from the lower right position and
loosen the remaining three, rotate counter clockwise then remove and place carefully on solid location
(typically the floor/decking).
CAUTION – the process isolation valve may leak so observe any
local safety procedures associated with the particular process unit/area.
f. Mount the “Process Inspection Port”, install the lower right Allen screw and securely fasten all four
screws. Connect the purge gas tubing and start the purge gas flow while opening the process isolation
valve. Using a flash light, the process nozzle can now be viewed through the window.
g. Use the reverse procedure to remove and re-install launch unit.
Figure 66- Insertion tubes, with insulation - materials, dimensions, etc. are specified to suit each different application