VOC1015
Executive summary
Two WARNING-level conditions were identified inside VOC Abatement Unit B: protective coating delamination on the inlet baffle exposing bare substrate, and wear streaks with debris on the rotary valve sealing face at the exhaust manifold. Media support screens on both sides clean up well with only cosmetic residual staining, and the main valve seal ring, valve face, and perforated screens are intact. External stack and gas train hardware are sound aside from minor weld-seam oxidation. Schedule coating repair on the inlet baffle and a rotary valve seal face inspection at the next planned outage before fouling and bypass leakage progress.
Prioritized actions
- 1 WARNINGStrip and recoat inlet baffle; address exposed substrate before corrosion undercuts adjacent coating.
- 2 WARNINGInspect rotary valve sealing face, measure wear, and clear debris from sealing land.
- 3 INFOVerify baffle-to-vessel wall seam integrity and reseal if gaps are confirmed.
- 4 INFORe-clean upper chamber walls to remove residual reddish-brown and pink staining for baseline.
- 5 INFOWire-brush and touch-up stack weld seams showing rust streaking to halt oxidation.
- 6 GOODDocument cleaned screen condition as baseline for differential pressure trending.
Findings
Findings
123Media support screen perforations are fully open after cleaning and edge fasteners remain seated. Reddish-brown residue persists on the upper refractory wall above the screen, indicating the wash did not fully reach that surface. No structural concerns on the screen itself.
Re-clean the upper wall during the next entry to remove residual deposit and establish a clean baseline.
123Welded panel seam and perforation pattern are intact and unobstructed. Pink staining remains across the screen face — cosmetic, consistent with process residue not removed by the wash. No blinding observed.
No action required; note staining as baseline and monitor for any increase in coverage at the next inspection.
123Main valve seal ring is continuous along the valve face edge and the perforated valve face is clean with no fouling. Inlet baffle shows minor surface discoloration only, no metal loss visible from this angle.
No action required; confirm baffle coating condition against Photo 4 close-up before closing the inspection.
123Close-up of the inlet baffle shows protective coating peeling away in sheets, exposing the underlying substrate to the inlet gas stream. The perforated plate itself is intact and unobstructed, but bare substrate will corrode rapidly under VOC-laden inlet conditions. The baffle-to-wall seam should be confirmed sealed while access is open.
Strip loose coating, prep the substrate, and recoat the baffle during the next planned outage. Verify and reseal the baffle-to-wall joint in the same work order.
1234Reference view confirms uniform perforation pattern on the valve face and intact seal rings on both opposing surfaces. Inlet baffle leading edge is visible above the valve face with no displacement. Use this image as the orientation reference for the findings in Photos 3 and 4.
No action; retain as reference image for next walkdown comparison.
123B-side media support screens show uniform perforation with no blinding, intact lower seam, and clean frame-to-screen interface. No debris accumulation observed.
No action required; continue routine DP monitoring.
123Cleaned media support screen with clear perforations, properly seated panel seam, and tight screen-to-wall edge. Condition is consistent with the B-side screens and represents a good post-clean baseline.
No action required; photo serves as cleaned-condition baseline.
123Exhaust manifold tube bundle is intact with no visible deformation and the bolted central hub flange is seated with only light surface deposits. The rotary valve sealing face, however, shows wear streaks and entrained debris — a precursor to bypass leakage and reduced VOC destruction efficiency.
At the next planned outage, pull the rotary valve, measure sealing face wear, clean the sealing land, and replace the seal if wear exceeds OEM limits.
123External walkdown of the exhaust fan, bearings, gas train, and fresh air/purge damper shows components in serviceable condition. Bolted flange ring shows no gasket weep, but rust staining is visible along the lower stack weld seam and minor oxidation on the upper vertical seam. Cosmetic at this stage, but worth tracking.
Wire-brush affected weld seams and apply touch-up coating at the next quarterly inspection to arrest oxidation.