Understanding Acoustic Pulse Reflectometry (APR) for Heat Exchanger Tube Inspection

Understanding Acoustic Pulse Reflectometry (APR) for Heat Exchanger Tube Inspection

Are you looking for an accurate and non-destructive way to inspect your heat exchanger tubes? Acoustic Pulse Reflectometry (APR) is a technique that can help you do just that. Here are some points to help you understand APR better:

How does APR work?

Acoustic pulse is injected into a straight walled tube and propagates down without generating any reflections. A microphone with its front surface flush with the internal tube wall is used to measure the pulse. When the pulse encounters a discontinuity in cross-section, it creates a reflection, the amplitude, and form of which are determined by the characteristics of the discontinuity.

How does APR detect defects in heat exchanger tubes?

Any discontinuities in the tube wall, such as a constriction or dilation, will create a reflection. The time of arrival of the reflection can be used to calculate the precise location of the discontinuity, and the shape of the reflection can infer the exact nature of the discontinuity. APR can detect defects such as blockage, hole, pitting, cracking, erosion, and corrosion.

How is APRIS different from other inspection techniques?

APRIS is a small, handheld device that can be easily carried along into tight workspaces. In addition to its portability, APRIS has several advantages over other heat exchanger tube inspection techniques. Unlike visual inspection or eddy current testing, APRIS does not require direct access to the tube's interior or any physical contact with the tube. This non-invasive nature of APRIS means that there is no need to cut the tube or insert probes or cameras into it, which can be time-consuming and expensive.

What are the advantages of APR?

APR is a non-destructive testing technique, meaning it does not damage the tubes during inspection. It is also a fast and accurate technique that can detect defects that other techniques may miss. APR can also be used to inspect tubes with complex geometries and bends.

Applications in industries

APR has been successfully used in various industries, including oil and gas, petrochemicals, and power generation. In one case study, APR detected a defective tube in a refinery, preventing an unplanned shutdown, and saving the company thousands of dollars in lost production.


In conclusion, APR is a reliable and non-destructive technique for heat exchanger tube inspection. Its accuracy, speed, and ability to detect defects that other techniques may miss make it an attractive option for many industries. If you're interested in learning more about APR or need heat exchanger tube inspection services, please contact us at info@talcyon.com.

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