Maintenance and cleaning methods of boiler tubes

The maintenance and cleaning methods of boiler tubes mainly include the following aspects:

1. Regular inspection
Appearance inspection: Regularly check whether the boiler tubes have corrosion, cracks, wear or other signs of damage.
Pressure test: Perform a water pressure test or air pressure test to check whether there are leaks in the boiler tubes.

Internal inspection: Check whether there are deposits or scaling inside the boiler tubes, and clean them if necessary.

2. Cleaning and descaling
Chemical cleaning: Use appropriate chemical agents to remove scale and other deposits. Note that the choice of agents should be suitable for the material of the boiler tubes.
Physical cleaning: Use high-pressure water jets or mechanical methods to remove difficult-to-dissolve deposits.
Regular drainage: Regularly drain the water in the boiler to reduce the formation of scale.

3. Anti-corrosion treatment
Anti-corrosion coating: Apply anti-corrosion coating to the surface of the boiler tube to prevent oxidation and corrosion.
Inner lining protection: For areas susceptible to corrosion, consider using corrosion-resistant materials for lining.
Adding corrosion inhibitors: Add an appropriate amount of corrosion inhibitors to the feed water to slow down the rate of metal corrosion.

4. Water quality management
Soften water quality: Use a water softener to reduce the hardness of the feed water and reduce the formation of scale.
Monitor pH value: Keep the pH value of the feed water within the appropriate range to avoid corrosion caused by excessive acidity or alkalinity.
Regularly test water quality: Regularly test the ion content (such as calcium and magnesium ions) in the feed water to ensure that it meets the standards.

5. Seal inspection
Replace seals: Regularly check and replace seals, gaskets and other wearing parts to ensure good sealing performance.

6. Safety valve and instrument maintenance
Safety valve calibration: Regularly calibrate the safety valve to ensure that its opening pressure is accurate.
Instrument calibration: Regularly calibrate pressure gauges, thermometers and other instruments to ensure accurate readings.

7. Record and document management
Maintenance records: Establish detailed maintenance records, including inspection dates, problems found and solutions.
Technical documents: Keep the technical data and instructions of the boiler for easy reference.

8. Professional training
Operator training: Ensure that all operators have received professional training and understand the correct operating methods and emergency response measures.

9. Comply with regulations
Follow regulations: Ensure that all maintenance activities comply with local laws, regulations and industry standards.

‌Maintenance methods during boiler shutdown:

‌1. Pressure maintenance: Applicable to shutdowns of no more than one week, keep the residual pressure in the boiler at 0.05~0.1MPa, and maintain the boiler water temperature slightly above 100℃.
‌2. Dry maintenance: Applicable to boilers that have been out of service for a long time, drain the water in the boiler, remove the dirt, rust and soot on the heating surface, place desiccants such as anhydrous calcium chloride, quicklime or silica gel, and keep the metal surface dry.
‌3. Wet maintenance: Drain the water in the boiler, remove scale and dirt, inject alkaline solutions such as sodium hydroxide or trisodium phosphate, and keep the boiler sealed.
‌4. Nitrogen filling method: Fill nitrogen into the boiler water system to maintain a certain positive pressure, prevent air from entering, and prevent corrosion.
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Precautions for boiler tube maintenance‌:

‌1. Keep the metal surface dry or isolated from the air‌: During the shutdown period, as long as the metal surface is kept dry or isolated from the air, it can effectively prevent corrosion‌.
‌2. Regular inspection and cleaning‌: Regularly inspect the various components of the boiler pipeline, clean the carbon deposits inside the burner and the burner nozzle, and check whether the valves, pressure gauges, thermometers and other equipment are working properly‌.
‌3. Anti-corrosion treatment‌: Drain the hot water pipe network, test the water quality, replace softened water, etc., take wet maintenance for the entire hot water pipe network and close all valves after filling with softened water‌.

The above methods can effectively extend the service life of the boiler tube and ensure the normal operation of the boiler system.

Read more: What are seamless boiler tubes and how are they made? or Boiler tube materials and standards