Api Rp 571 Pdf Now

She re-read the classic line: "High temperature naphthenic acid corrosion (NAP) is characterized by sharp, knife-edged pits or grooves with a scalloped appearance, often in high-velocity areas."

She knelt by the heater’s transfer line. There it was—barely visible under a layer of coke, a series of small, sharp-edged grooves. Not the wide, smooth wash of sulfide corrosion. These were scalloped , just like the photo in API RP 571.

She frowned. The unit processed a heavier, more acidic crude slate than last year. She grabbed the tattered, coffee-stained copy of from her shelf—the "bible" of damage mechanisms. It fell open to Section 5.1.10: Naphthenic Acid Corrosion . api rp 571 pdf

She taped a note above her desk: "The damage mechanism doesn't care about your schedule." Would you like a version focused on a different damage mechanism from API RP 571, such as High-Temperature Hydrogen Attack (HTHA) or Chloride Stress Corrosion Cracking (CSCC) ?

Marta opened the attached spreadsheet. It listed the usual suspects: thickness readings, hardness tests, and a few spot checks for creep in the heater tubes. She scrolled past the rows of standard checks, then paused. Her eyes landed on a small header: High-Temperature Naphthenic Acid Corrosion (NAP) — marked "Not Required." She re-read the classic line: "High temperature naphthenic

She pulled up the crude assay for the next two years. TAN: 1.2. Temperature at the heater outlet: 620°F.

Silence on the line.

"Final NDE scope for the Crude Unit heater," he wrote. "Sign off by Friday."