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. It does not discuss the interpretation of inspection data, nor does it consider inspection and quality assurance requirements for new or replacement construction. These guidelines are not intended to supersede or replace jurisdictional and regulatory requirements.