Introduction

Flanged immersion heaters are crucial components in various industrial processes, providing efficient heat transfer in tanks and vessels. To ensure their optimal performance and longevity, implementing effective maintenance strategies is essential. In this blog, we will explore the key aspects of maintaining flanged immersion heaters. Understanding their functionality, common issues and failures, preventive maintenance strategies, corrective maintenance techniques, and advanced tips to extend their lifespan.

Flanged industrial immersion heaters are among the most popular heaters owing to their wide customization, easier installation, and operations in a stringent environment.

Made by brazing or welding flange with several hairpin elements or bulge tubular elements, designed for heating chemical, petroleum, and water-based applications, especially heat transfer fluids, medium and lightweight oils, and water in tanks and pressure vessels.

Understanding Flanged Immersion Heaters

For any production or processing facility, when a large volume of fluid is heated before pumping out to process applications, Immersion heaters are always the best-recommended solutions.

A single bundle or multiple smaller units can be installed in the tank for uniform heat transfer and steady heating of the fluid. All safety precautions inbuilt within the heater and control system.

Encase flanged immersion heaters in a flange that welds or bolts to the side of a tank or vessel. Design these heater to heat liquids, gasses, or solids by directly immersing the heating element into the substance. Understanding the basic components and operation of flanged immersion heaters is crucial for effective maintenance.

Below is the construction of the immersion heater for a better understanding of how to maintain it:

1. Terminal Enclosure

Marathon flameproof heaters are certified to install in hazardous areas Zone 1 and 2, Gas Group IIC, IP66. The terminal enclosure is designed to protect the terminals of the individual elements from external impacts, such as dust, moisture, etc., and to facilitate the connection of the incoming power supply to the heater bundle.

2. Heater Bundle

Consists of a number of U Pin heating elements adequately supported by a set of Baffles and Tie rods, designed to deliver the specified temperature at the outlet by maintaining the element temperature and pressure drop within safe limits. Heating elements can be fixed to the heater flange by means of standoff sleeve pipes with brazing or direct welding or by means of threaded couplings. The heat duty of a bundle can be divided into many subgroups (banks) based on process conditions. This will help in better control and flexibility in the operation.

3. Temperature Sensors

The heater bundle will have an element skin temperature sensor for monitoring and regulating the element skin temperature within the limits. The unit may also need additional sensors such as tube sheet temperature sensor, terminal box sensor, vessel Body temperature sensor, and process fluid Temperature sensors based on case-to-case. 

The sensors used for the system will be certified in accordance with the area of installation. The temperature sensors are typically RTD or Thermocouple. A simple heater bundle can also be controlled using thermostat protection for skin and process temperature. If the operation pressure is high, it is recommended to have a PSV (Pressure Safety Valve) installed within the heater vessel as an additional safety measure.

Common Issues and Failures

Like any equipment, flanged immersion heaters can encounter various issues and failures over time. Some common problems include corrosion, scaling, electrical failures, thermostat malfunctions, and leaks. By identifying these issues early on, you can prevent costly repairs and extend the lifespan of your immersion heaters.

The common problems that flanged immersion heaters may encounter are corrosion and the impact of different fluids on the heating elements. Scaling issues caused by the deposition of minerals or sediments.

Preventive Maintenance Strategies

Implementing preventive maintenance strategies is crucial for avoiding unexpected breakdowns and ensuring the long-term functionality of flanged immersion heaters. Regular inspections, cleaning, and testing of electrical components, monitoring of fluid conditions, and maintaining proper seal integrity are some of the key preventive measures to undertake.

Regular inspections

Conducting routine inspections is an essential part of preventive maintenance for flanged immersion heaters. This involves visually examining the heater unit, electrical connections, and surrounding components to identify any signs of wear, damage, or potential issues. By regularly inspecting the heaters, detect problems early on, allowing for timely repairs or replacements to prevent unexpected breakdowns.

Cleaning

Keeping the flanged immersion heaters clean is another important preventive maintenance strategy. Over time, dust, debris, and other contaminants can accumulate on the heating elements, reducing their efficiency and potentially causing malfunctions. Regular cleaning helps to maintain optimal heat transfer and prevents the buildup of deposits that could lead to corrosion or electrical problems.

Testing of electrical components

Flanged immersion heaters rely on electrical components to function properly. As part of preventive maintenance, testing these components is crucial to ensure their reliability and performance. This typically involves checking the electrical connections, wiring, controls, and safety devices to verify their integrity and functionality. By identifying and addressing any electrical issues early on, reducing the risk of unexpected breakdowns or safety hazards.

Monitoring fluid conditions

Flanged immersion heaters often heat fluids, such as water or oil. Monitoring the condition of the fluid is an important preventive maintenance strategy. This can involve checking the temperature, pressure, and flow rate of the fluid, as well as monitoring its chemical composition or any contaminants present. Regularly monitor the fluid conditions to detect any abnormalities or changes, allowing you to make necessary adjustments or maintenance actions before they lead to equipment failures or performance issues.

Maintaining proper seal integrity

Flanged immersion heater typically installed with seals or gaskets to prevent leaks and ensure the integrity of the system. As part of preventive maintenance, it is important to inspect and maintain these seals regularly. This may involve checking for signs of wear, replacing damaged seals, or applying lubrication to ensure proper sealing. By maintaining seal integrity, minimize the risk of fluid leaks, which can damage the equipment and cause operational issues. 

Corrective Maintenance Techniques

Despite your best preventive efforts, issues can still arise with flanged immersion heaters. In such cases, having effective corrective maintenance techniques in place is vital. Promptly addressing electrical faults, replacing faulty components, descaling, and repairing leaks are some of the corrective actions that can help restore the optimal performance of the immersion heaters.

Advanced Maintenance Tips

For those seeking to go beyond the basics, advanced maintenance tips can significantly enhance the longevity of flanged immersion heaters. These include implementing corrosion-resistant coatings, using sacrificial anodes, installing protective covers or insulation, employing advanced monitoring systems, and considering periodic equipment upgrades.

Conclusion

Maintaining flanged immersion heaters is crucial for ensuring their long-lasting performance and avoiding unexpected downtime. By understanding their operation, identifying common issues, implementing preventive maintenance strategies, you can optimize the efficiency and extend the lifespan of your flanged immersion heaters. Remember, a well-maintained heater not only saves costs but also contributes to the smooth functioning of your industrial processes.

Explore more about Industrial Heaters at Marathon Heater and experience the innovation driving heating and sensing technologies forward.

Contact us at enquiry@marathonheat.com for your requirements.