Tubular Heat Exchangers – Nondestructive Testing in Heat Exchangers and Its Role in Industry

Heat exchangers are widely available in many industries and help move heat quickly from one environment to another. They are used in a wide variety of fields such as space heating, cooling, air conditioning, chemical plants, power plants, petrochemicals and petroleum. Heat exchangers are often used in industry to siphon waste heat from one part of a process to another rather than introducing a new external heat source. This practice increases efficiency and saves many industries a great deal of money and also helps protect the environment.

Because industries involving the use of heat exchangers almost by definition involve high temperatures, pressures and large quantities of potentially harmful liquids, it is important to ensure that the equipment involved is serviced to a high standard. Not only for safety implications, but also to keep precisely calibrated processes in place and maintain cost efficiency. Contamination of fluids or temperature drops can cause PH changes in fluids or inefficiencies in processes that result in lost productivity and ultimately lost revenue. Along with pollution and minor defects, major defects can cause unplanned downtime and failures that result in large amounts of lost revenue.

So what is the answer? NDT, or NDT as it is more commonly known, is the answer. Its role is to analyze materials and parts using techniques that do not harm the materials involved. Using techniques such as ultrasound, radio, and magnetism, parts can be examined without the need for disassembly or damage.

In the case of heat exchangers, NDT offers many different methods for their inspection. Different techniques are used for different applications, depending on needs such as time, cost and precision. Some of the main technologies involved are: Far Field Electromagnetic Technique (RFET), IRIS (Internal Rotary Control System), Eddy Current Test (ECT), MagWave and Remote Visual Control (RVI).

RFET is one of the main inspection methods and is used to test carbon steel pipes. A probe is placed at one end and pushed upwards through the tube, then the probe is slowly withdrawn and withdrawn at a constant rate giving the data to be analyzed. Typical defects and defects found include general erosion/corrosion, pitting and split shear (backing plate wear).

The RFET is capable of testing 300-500 tubes/shift and tolerates low fill factors. It can detect ID (Inner Diameter) and OD (Outer Diameter) defects and supports a wide range of probe sizes from 0.250″ (up to 6.35 mm), although custom probes can be produced for almost any situation. can be provided.

NDT is recommended in the UK as part of a WSE (Written Exam Schedule) as required by the HSE. For the relatively low cost of NDT, its frequent use can help prevent accidents, fatalities and unexpected downtime and thus huge loss of revenue, making it essential for a knowledgeable and efficient plant.

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