scope:

This Technical Information Paper (TIP) provides guidelines and procedures that may be used to detect and characterize cracks in composite tubes of black liquor recovery boilers. The document addresses inspection frequency, boiler preparation and tube cleaning for inspection, critical inspection locations or features, nondestructive testing (NDT) methods and inspector qualifications. It does not cover interpretation of inspection results, nor consider inspection and quality assurance requirements for new tubes. These guidelines do not supersede or replace jurisdictional and regulatory requirements.