RTO
They're highlighted below with the New tag. Regenerate the card to fold them in.
The 16 steps Luthier walks every technician through for this equipment type. Severity signals show what to flag.
baseline v2- Step 01 · Overall Unit
Capture overall RTO view and back view
Overall and back-side views document general condition and provide context for any localized findings.
Focus: Photograph the full unit and rear; note any external damage, leaks, hotspots, or housekeeping issues.Severity signals (4)
- no external issues → NONE
- context shot referencing internal findings → LOW
- visible external damage or rust/corrosion → HIGH
- external hot spot - glowing metal or burned/missing paint → CRITICAL (do not touch; contact Durr)
- Step 02 · Internal Insulation / Refractory
Inspect internal insulation and refractory (chamber & tunnel)
Section 5.3 directs that internal conditions be documented with photographs. Cracked, loose, or separated ceramic-fiber insulation and hot spots indicate refractory degradation that can lead to shell hot spots and heat loss.
Focus: Through the access doors (cooled unit only), photograph combustion chamber and tunnel walls. Look for cracks, loose or separated insulation, sapping / hot-spot discoloration, and loose hardware.Severity signals (4)
- intact insulation, no cracks → NONE
- minor surface cracking → LOW
- loose/separated insulation or loose hardware → MEDIUM
- hot-spot/sapping or exposed shell → HIGH (contact Durr)
- Step 03 · Heat Exchange Media
Inspect ceramic media bed hot face (top of bed)
The ceramic heat-exchange media is the heart of the RTO. Durr recommends photographing the media bed hot face on a regular basis (maximum 6-month interval) to trend its condition. Breakage or plugging raises pressure drop and degrades VOC destruction.
Focus: Photograph the top surface of each media bed. Look for cracked or collapsed ceramic blocks/saddles, loose surface dust, plugging by inorganic/alkali material, and an uneven bed surface. Compare the A and B beds.Severity signals (4)
- clean, intact, level bed → NONE
- loose surface dust / light plugging → LOW
- localized breakage or organic buildup → MEDIUM
- excessive breakage or inorganic/alkali plugging → HIGH (contact Durr)
- Step 04 · Cold Face Screens
Inspect cold face / B-side screens (and post-cleaning condition)
Screens at the cold face must remain clean and intact for proper flow and heat recovery.
Focus: Verify screens are free of obstructing buildup, tears, or deformation; document cleaned condition after maintenance. Also inspect the cold-face media support surface for corrosion and organic/inorganic particulate or chemical attack.Severity signals (4)
- clean and intact → NONE
- partial fouling → LOW
- heavy fouling or tears → MEDIUM
- corrosion or chemical attack on cold-face support → HIGH (contact Durr)
- Step 05 · Media Support
Inspect baffle plates at media support
Baffle plates support the media bed and distribute flow; damage or fouling can compromise media retention.
Focus: Check baffle plate condition for deformation, missing sections, or residual buildup, especially after screen cleaning.Severity signals (2)
- intact and clean → NONE
- deformation or missing plates → HIGH
- Step 06 · Manifold
Inspect manifold interior for process buildup
Material buildup inside the manifold is the most recurrent defect on this fleet and can foul switch valves, the valve lift pancake cylinder, and valve spindle bearings.
Focus: Look at manifold interior walls and the zone around the switch valve, valve lift pancake cylinder, and valve spindle bearing for deposits, scaling, or accumulated process material.Severity signals (3)
- any visible deposits in manifold → MEDIUM
- buildup contacting or restricting valve/cylinder motion → HIGH
- clean walls → NONE
- Step 07 · Switch Valve
Inspect inlet baffle, valve face, and main valve seal ring
Valve face and main seal ring integrity determine switching seal quality; the inlet baffle directs flow.
Focus: Check the valve face and main valve seal ring for wear, scoring, distortion, or deposits; verify the inlet baffle is in place and undamaged. Seal rings are lubricated with molybdenum-disulfide and are inspected/repacked with the bottom taper-roller bearing at the 5-year interval - note any wear that warrants replacement.Severity signals (4)
- clean undamaged surfaces → NONE
- deposits or wear on seal ring → MEDIUM
- deformation or breach of seal ring → HIGH
- worn seal rings at 5-yr service → replace
- Step 08 · B-Side Valve
Inspect B-side valve assembly
Each side valve must seal and switch reliably; document B-side condition separately from A-side.
Focus: Photograph and inspect the B-side valve for surface wear, buildup, and proper seating.Severity signals (2)
- no abnormality → NONE
- deposits or surface damage → MEDIUM
- Step 09 · Switch Valve Drive
Inspect switch valve drive (AC drive, spur gears, lift cylinder, sensors)
The electric switch-valve drive - AC drive, gearbox, spur gears, pneumatic lift (pancake) cylinder, and stop/crawl proximity sensors - alternates the beds about every 3 minutes. Faults here halt RTO operation.
Focus: Confirm the AC drive housing, mounting, and wiring are sound with no fault indicators. Inspect the valve-drive spur gears for tooth wear, the pneumatic lift (pancake) cylinder for piston-seal/air leaks, and the stop/crawl proximity sensors for the correct ~4 mm gap and intact targets.Severity signals (3)
- drive, gears, cylinder, and sensors all nominal → NONE
- loose mount/wiring or minor gear wear → MEDIUM
- excessive spur-gear wear, lift-cylinder seal leak, or non-functional drive → HIGH (Durr technician only)
- Step 10 · Pressure Cabinet
Inspect pressure cabinet interior
Pressure cabinet houses pneumatic and electrical components that drive valve lift and switching; integrity is essential.
Focus: Open and document cabinet interior; check for leaks, loose fittings, damaged wiring, and overall cleanliness.Severity signals (3)
- clean, no leaks, orderly → NONE
- minor leak or loose component → LOW
- active pneumatic leak or electrical fault → HIGH
- Step 11 · Burner
Inspect burner stone, nozzle, gas train, transmitter, mount, and combustion air damper
Burner inspection covers all combustion-side components that must be intact for stable, safe firing.
Focus: Verify burner stone integrity, nozzle condition, gas train tightness/leaks, gas transmitter function, burner mount, and combustion air damper position. Observe the burner flame through the sight port for stability and shape (weekly check); see the spark-ignitor step for ignition components.Severity signals (4)
- all components nominal → NONE
- minor wear or soot → LOW
- unstable, lifting, or sooty flame → MEDIUM
- cracked stone, deteriorated nozzle, or gas train leak → HIGH
- Step 12 · Spark Ignitor
Inspect spark ignitor
The spark ignitor is a wear consumable replaced semiannually, or sooner if frequent flameouts occur. A cracked, fouled, or burned ignitor causes ignition failures.
Focus: Remove and photograph the spark ignitor tip. Check for cracked porcelain, a bent or burned electrode, and a coated/fouled probe. A coated but undamaged ignitor can be wire-brushed and reused; cracked/bent/burned must be replaced.Severity signals (3)
- clean, intact tip → NONE
- light coating (cleanable) → LOW
- cracked porcelain, bent or burned electrode → HIGH (replace)
- Step 13 · Gas Train
Verify inlet gas pressure gauge reading and stability
Unstable or low inlet gas pressure causes burner faults at high demand and is a HIGH-severity reliability concern.
Focus: Read inlet gas pressure gauge at high burner demand; watch for drops below 50" w.c., recurrent low-gas-pressure faults, and whether the plant regulator is already at its maximum.Severity signals (3)
- stable, well above 50" → NONE
- marginal fluctuation → MEDIUM
- drops below 50" with faults / regulator maxed → HIGH
- Step 14 · Exhaust Fan
Inspect main exhaust fan (wheel, housing, bolts, drive)
The VFD-controlled main exhaust fan draws solvent-laden air through the RTO. Wheel/housing wear or corrosion and loose mounting are reliability and safety concerns.
Focus: Photograph the fan wheel, inlet cone, and housing for wear, erosion, corrosion, or material buildup. Check foundation/wheel bolts and set screws, and (if belt-driven) belt alignment/tension and coupling alignment.Severity signals (3)
- clean, no wear or corrosion → NONE
- light dust / surface rust → LOW
- wheel, inlet-cone, or housing wear or corrosion → HIGH (contact Durr)
- Step 15 · Dampers & Actuators
Inspect isolation, fresh-air, and bypass dampers & actuators
The pneumatic isolation and fresh-air dampers fail closed on loss of power or compressed air and are key fire-safety devices; leakage can cause condensate buildup and a fire hazard (NOTE in Section 5.5).
Focus: Photograph each damper actuator, linkage, and shaft seal. Check for air leaks at cylinder shaft seals, loose or worn linkages, and correct open/closed position markings. Confirm dampers move freely and are not seized.Severity signals (4)
- actuators/linkages intact, no leaks → NONE
- minor linkage play → LOW
- shaft-seal air leak or worn linkage → MEDIUM
- damper seized or failing to seal (condensate/fire path) → HIGH
- Step 16 · Compressed Air System
Check compressed-air filter/regulator and supply pressure
Compressed air operates the switch valve and pneumatic dampers. Below 65 psi the unit faults and shuts down; the working setpoint is 80 psi (5.5 bar).
Focus: Photograph the compressed-air filter bowl and regulator gauge. Check for water/debris in the bowl, drain the sump, and verify the gauge reads about 80 psi (well above the 65 psi shutdown threshold).Severity signals (4)
- ~80 psi, clean dry bowl → NONE
- moisture/debris in bowl → LOW
- pressure drifting toward 65 psi → MEDIUM
- below 65 psi (shutdown threshold) → HIGH