Industrial boilers are very important equipment in a wide range of industries. They are responsible for generating and accumulating steam under high pressure and temperature. However, depending on their usability and lack of maintenance, they may present some defects.

These defects can cause anything from a drop in the productivity of industrial boilers to the complete shutdown of the equipment. They can also cause fatal accidents, resulting in the total collapse of the equipment .

So, learn about the 7 main causes of defects in industrial boilers that you need to always be aware of.

Thermal shock

The first of the defects in industrial boilers is thermal shock. This problem usually occurs due to the frequent stopping and restarting of the boiler's combustion chamber, which is responsible for heating the water. The boilers exposed to thermal shock are normally operated manually, on/off.

To illustrate this defect, it is worth mentioning the discontinuous supply of cold water to the boiler.

By doing this, the temperatures of the industrial boiler tubes will vary very constantly. As a result, the boiler tubes will contract and expand more constantly, causing thermal shock and reducing the safety of the equipment.

Corrosion in boiler parts

In some industrial boiler components, corrosion is a natural problem, regardless of type and usability. The corrosive process is represented by the reduction in the thickness of the boiler surfaces subjected to higher pressures.

In industrial boilers, corrosion can occur in several ways, with internal corrosion, generalized oxidation of iron, galvanic corrosion, corrosion by differential aeration and saline corrosion being the most important.

Corrosion can be a serious problem in boilers, mainly due to the possibility of cracks forming and reducing the thickness of the boiler walls. Therefore, it is necessary to keep boiler maintenance up to date.

Defects in welded joints of industrial boilers

During construction, the boiler undergoes welding processes in several parts. Therefore, to ensure the safety of the equipment, the welds need to be very well done, especially on the tubes, mirrors, pipes, reinforcements, stays, and other parts of the boiler.

Any failure in welded joints represents an increase in risk, as these are the areas with the lowest metal resistance. Therefore, during the manufacturing process, it is mandatory to follow the ASME IX Standard, related to the qualification of welders and welding operators.

Water and steam leaks from inside the boiler

In industrial boilers, water or steam leaks are one of the main defects. Therefore, it is important to be aware that there may be several causes of leaks, such as:

• Valve seats that have been damaged or are stuck;
• Poorly placed cover or flange gasket;
• Boiler pipe that is punctured or cracked;
• Overheating followed by rapid cooling, causing the tubes to come loose from the mirrors.

Water entrainment within the steam generating system

This is another of the defects that occur in industrial boilers. As the name suggests, carryover is a phenomenon characterized by the passage of water from the boiler to the steam line, causing several undesirable problems.

Among these drawbacks, some of the most important can be mentioned:

• Formation of deposits in superheaters, turbines, valves and accessories of the post-boiler section;
• Drop in the performance of equipment that uses steam for heating;
• Formation of water hammers in the lines.

Defects related to reaming

As with welded joints, defects in mandrels are causes of defects in industrial boilers. Mandrels are understood as the operation of expanding the tubes along the holes in the boiler plates.

Through this operation, the pipes are anchored with the appropriate watertightness, that is, free of holes, cracks or porosities. However, if foreign bodies appear on the external surface of the pipe ends or in the walls, this watertightness may be compromised and cause problems that, in some cases, can become quite serious.

Lack of maintenance of industrial boilers

As we have seen so far, the main causes of defects in industrial boilers are directly related to negligence in the construction and maintenance of the equipment, that is, the pressure valve is defective, the water levels are low and/or the construction did not follow the standards.

To avoid this type of problem, regular maintenance of industrial boilers is essential . Maintenance should always be carried out in accordance with the manufacturer's recommendations and regulatory standards, which allow for greater safety in the operation of pressure vessels, boilers and pipelines.

To learn more about industrial boilers and their devices, we invite you to continue following the MBX blog .