DESCRIPTION SHELL SIDE TUBE SIDE
SERVICE CATACARB SOLUTION EFFLUENT GAS-H2, NH3, etc
TEMPERATURE 120C
MATERIAL A285 Gr C clad with ss 304 ASTM A213 TP 304L
We have a semi-lean generator which regenerates catacarb soluton in ammonia plant, the specs of which are given above.
During TA 2015, failure of weld joint of tube-tubesheet weld was observed, also tubes were leaking from near the expanded joint.
When repair welding is done. More cracks are generated in the tubesheet which propagate to other weld joints of nearby tubes.
Tubesheet material is A240 TP304.
Any idea what might be the reason.
Chloride ppm in catacarb solution is 50 ppm at 120 degree C.
Also how to repair the two types of leakage as welding is not effective and plugging may not rectify the leakage from the rolled joint space between tube & tubesheet.
refer to the drawing.
the tubesheet is double and the weep holes have been plugged o get rid of leakages
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