Reactors Internal Inspection
1. Inspection Ports
Obtain measurements at corrosion reference points on reactor shell. Inspect for corrosion or scale at these locations. Loose scale on the bottom head is probably a combination of scale and catalyst. This scale can cause corrosion and must be removed.
2. Basket Tray
Inspect for basket screen deterioration and plugging. Report percentages of plugging. Plugged screens can be cleaned by hydroblasting. Thin or corroded screens should be replaced.
3. Quench Flex Hoses
Look for broken bonding or severely distorted hoses. If hoses are distorted and bonding is bunched up, replacement will probably be required. Hoses may require hydrotesting to determine soundness. Hydrotest up to 250 psig.
4. Catalyst Support Screens
Inspect for corroded or holed-through areas often caused by hot spots, where the catalyst can migrate through the screen. Do not overlook internal manway cover screen. Inspect screens for plugging, and report the percentage of plug-ging. In most cases plugged screens can be cleaned by hydroblasting. Inspect space cloth where screens have corroded through; any thinning might necessitate replacement. Loss of aluminized coating on screens will reduce screen life to approximately 1 year, and screens so affected should be replaced. Obtain a screen sample for a bend and brittleness check.
5. Tray Support Beams
Visually inspect for any distortion or cracked welds. Inspect to determine if each tray (bed) is properly supported. Slight bowing upward was noted on one reactor which was caused from reverse flow through the reactor.
6. Tray Sections
Inspect for cleanliness and condition.
7. Thermowell Bundles
Inspect for external iron sulfide scaling and corrosion. Obtain O.D. measurements. Several thermowells have required replacement because of severe external loss.
Pressure test with helium or nitrogen. If pressure drops, leaks can be located with a Delcon ultrasonic translator (noise detector).
8. Quench Lines
Note if they are in position; failure can be expected at threaded connections below support tiers. This has occurred at Richmond.
9. Catalyst Dump Pipe (in sections)
Inspection to be made after removal from the reactor. Look for corrosion, wear, and distortion. Any leak can cause bypassing around catalyst beds, and may require unloading the reactor to repair.
10. Inner Bottle
Inspect wall for scale, pitting and cracks. Any corrosion or excessive scaling should be reported.
11. Ladders
Inspect for condition.
Categories: In-Service Inspection | Tags: Basket Tray, hydroblasting, Hydrotest, Thermowell, Tray | Leave a comment