Methods To Inspect Heat Exchanger Tubes

Methods to inspect Heat Exchanger Tubes

To thoroughly inspect your Heat Exchanger, you must first understand its inner structure and its working. However to learn more about heat exchanger tubes you need to ask yourself these questions – ‘What exactly are heat exchanger tubes?’ and ‘What is their purpose?’. Only then you will be able to properly inspect any kind of Heat Exchanger.     

What Are Heat Exchanger Tubes?


A Heat Exchanger is composed of numerous tubes, which are mounted inside a cylindrical shell. This complex but uniform network of tubes holds two kinds of liquid or fluids which help in the exchange of heat. Each fluid serves a different purpose, one of them flows through the outermost part of the shell while the second fluid flows through the central part of the shell.

You can generally see a parallel or cross-sectional arrangement of tubes in a heat exchanger. Now that we possess a general knowledge about the structure of Heat Exchanger Tubes, we also need to figure out the motive behind the installation of such sophisticated machinery.


What Purpose Do They Serve?

One of the main functions of heat exchanger tubes is to maintain or regulate the temperature. Just like many of us are thankful for an air conditioner that cools us down during summer, similarly, the goal behind installing Heat Exchanger is sometimes to simply cool down a large facility. Its mechanism allows it to act as a large-scale air conditioning system. The heat exchanger possesses numerous tubes which are full of fluids so it can easily regulate the temperature of any large-scale production facility.


Why You Should Periodically Inspect Your Heat Exchanger Tubes?

Heat exchangers are commonly used to heat or cool down large-scale facilities like – power plants, sewage treatment plants, chemical plants, and refineries. The tubes inside a heat exchanger should be inspected at regular periods because it will make you aware of any wall loss or other types of corrosion that may have occurred in the exchanger. These faults can take up a lot of resources to get fixed. Although a heat exchanger is quite a convenient thing to have its maintenance can cost you quite a bit. However, If we leave it unattended for a while it will potentially lose its durability and function.


How To Inspect Heat Exchanger Tubes?

As you are already aware a multi-tube heat exchanger is composed of a bundle of tubes but this network of tubes is very thorough and it contains hundreds of tubes in it. Depending on the method, all these tubes can be inspected thoroughly or partially and the defective tubes are either replaced or sealed off. Because of its structure, the inspection can take a lot of time and effort but employing proper methods can save a lot of your resources. S

Following are 3 methods you can use to properly inspect your Heat Exchanger Tubes:-



Method 1: Eddy Current Testing


  • The first one on the list is Eddy Current Testing (ECT). This method requires no human contact but by using it you can detect any type of metal discontinuities pretty easily.
  • These metal discontinuities can be corrosion, erosion, wear, pitting, baffle cuts, wall loss, and cracks in the inner walls of tubes.
  • This method only works when the tubes in the heat exchanger are made up of certain metals. The potential defects are detected by any disruption in the flow of eddy current.

Method 2: Internal Rotary Inspection System (IRIS)

  • The second method on the list is the internal rotary inspection system (IRIS). Unlike the Eddy Current Testing, it’s a contact method in which ultrasonic waves are often used in petrochemical and balance-of-plant (BOP) tube inspections.
  • IRIS utilizes pulse-echo mode where ultrasonic pulses are transmitted throughout the tubes to the probe.
  • Through this method, you can measure and determine the wall thickness, material loss, and defect orientation.
  • The range in which it detects any disorientation is usually up to 0.5 inches to 3 inches.

Method 3: Visual Inspection Using a Videoscope


  • This method is ideal for inspecting difficult-to-access areas.
  • Through visual inspection, you can be more sure of any abnormalities and videoscope helps in this assessment.
  • It has a small sensor chip located near the tip which enables it to capture videos and still images. Through this method, you can remotely inspect your heat exchanger tubes from time to time.                                                                                                                                                                                                        Subzero Solution is a  tube expander manufacturer in India. We provide quality tools and services to the  Heat exchanger, Boiler manufacturing, and Re-tubing industry.