INSPECTION FOR CRACKING OF COMPOSITE TUBES IN BLACK LIQUOR RECOVERY BOILERS

• This Technical Information Paper (TIP) provides guidelines and procedures that may be used to identify cracks that form in composite tubes of black liquor recovery boilers during service.
• The document addresses inspection frequency, boiler preparation and tube cleaning for inspection, critical inspection locations or features, nondestructive testing (NDT) methods, and inspection personnel qualifications.
• Composite tubes are commonly specified as corrosion-resistant replacements for carbon steel tubes in recovery boiler floors, walls and occasionally in super heaters. The most commonly used tubes are co-extruded with a 304L ( UNS30403 ) stainless steel outer layer over an SA-210 carbon steel inner core.

It Provides information on:

• Scope.
• Safety Precautions.
• Inspection frequency.
• Boiler preparation.
• Inspection techniques.

Who will benefit:

• Quality Manager.
• Engineers.
• Maintenance Manager.
• Safety Manager.
• Supervisor.