Ultrasonic testing (UT) for tube thickness measurement in black liquor recovery boilers: Part I - Guidelines for accurate tube thickness testing; Part 2 - Default layouts for tube thickness surveys in various boiler zones

Following a review of general considerations related to UT thickness testing of boiler tubes, Part I of this TIP provides guidelines and procedures for acquiring accurate ultrasonic thickness readings on boiler tubes, where the tube material and condition are conducive to such non-destructive thickness testing. Part II describes how tube thickness surveys are commonly laid out for different zones of a typical recovery boiler. It also stresses that a customized survey is essential for each boiler.