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Ethylene furnace tube outage record

2026-06-10 · Pyrolysis cracking furnaces, quench exchangers & transfer-line valves (API 530 / API 579)

Measured outcomeRadiant-coil replacement scope optimized per pass using trended OD growth, bow, and carburization NDE data.

In an ethylene steam cracker, the pyrolysis furnace radiant coils and transfer-line exchangers (TLEs) operate at extreme temperatures where carburization, creep, thermal shock during decoking, and tube bowing govern run length. Replacing a radiant tube harp too early wastes capital; running it one decoke cycle too long causes a tube rupture and an unplanned furnace outage.

Current state before intelliSPEC

  • Coil measurements scattered by furnace and pass: Magnetic permeability (carburization) scans, ultrasonic wall readings, tube OD growth measurements, and visual bow assessments were stored in separate Excel sheets per furnace cell.
  • No link between decoke history and coil damage: Thermal excursions and decoke counts lived in the process historian while physical NDE lived in contractor folders, preventing coil-by-coil API 530 / API 579 Part 10 creep life tracking.
  • Rush decisions during short decoke stops: During a 48-hour maintenance outage on a single furnace, engineers had to decide which outlet fittings or crossover tubes to weld-repair before the box was closed.

Configured path

The complex implemented intelliVISION, intelliEDGE, intelliINSPECT, intelliNDT, intelliINTEGRITY, and intelliPROJECTS.

  1. Pass-and-elevation coil register: Every furnace cell, radiant pass, tube elevation, spring hanger, and TLE tube sheet was modeled in .
  2. Offline furnace-box capture: As soon as the firebox cooled and LOTO cleared, inspectors entered with to log carburization profiles, OD caliper readings, hanger positions, and TLE tubesheet PT/UT calls.
  3. Coil remaining-life and turnaround staging: and trended carburization and wall loss across decoke cycles, feeding harp-replacement orders into and staging spare coils in .

Measured outcome

  • Coil replacements driven by pass-level data: Planners replace only the radiant passes or outlet cones that have reached carburization or diametral-growth limits.
  • Faster furnace-box closeout: All NDE, weld repairs, and spring-hanger cold/hot settings are signed on the tablet before refractory doors close.
  • Auditable furnace mechanical integrity: Complete coil genealogy, heat numbers, and inspection histories stay linked per furnace cell.