The Value of a Baseline Inspection on New Fired Heater Tubes

Overview

A common practice employed in new construction and tube replacement projects is a baseline inspection of the fired heater coils. With the advent of smart pig technology, these baseline inspections have the ability to detect manufacturing defects that otherwise may go undetected. According to inspection findings, almost 85% of new fired heater tube inspections contain one or more defects exceeding the manufacturer’s design tolerance for minimum wall thickness (see Figure 1).

Owner-operators should not overlook this first step in coil integrity management. Besides the obvious reduction in a tube’s life expectancy, defects may lead to premature and unexpected failures causing harm to personnel, equipment damage, unscheduled shutdowns, and lost production.

As two case histories illustrate, knowing the condition of fired heater tubes before they are commissioned, either as part of a new expansion project or when replacements are made in existing heaters, may save a lot of headache in the future. The technology employed for these baseline inspections was FTIS (Furnace Tube Inspection System), which is a high resolution in-line ultrasonic smart pigging tool.