Why are boiler pipes so important?
Imagine: In the dead of winter, the wind is biting. If a factory production line is forced to stop due to a boiler pipe leak, it will result in tens of thousands of losses per hour. In the home, the heating system has no heating due to pipe corrosion, and people are shivering. The culprit in these scenes is a boiler pipe that is particularly easy to be ignored.
Boiler pipes are the carriers of heat energy transfer. Every link, including design, material, installation and maintenance, is crucial. This article will deeply analyze the relevant knowledge such as the type selection of boiler pipes to help you avoid risks and extend the life of equipment.
What is a boiler pipe?
Boiler pipes are the core of the boiler system, used to transport high-temperature water, steam or hot oil. In order to ensure the normal use of boiler pipes, they must have the following characteristics:
High pressure resistance: This is the most basic requirement. Because the internal pressure of the boiler pipe exceeds 1 MPa, it must be resistant to high pressure to ensure normal operation to prevent breakage and leakage.
Corrosion resistance: The water inside the boiler pipe and the smoke after combustion contain a variety of chemicals, which will corrode the pipe, so it is necessary to ensure that the pipe has a certain degree of corrosion resistance.
Efficient heat conduction: This is one of the core special effects of the boiler pipe. The function of the boiler pipe is to transfer heat to meet the heating needs. Therefore, optimizing the heat exchange efficiency can not only improve the overall performance of the system, but also effectively reduce energy consumption.
Boiler Tubing Types and Selection Guide
Seamless pipe vs welded pipe
|
type |
Advantages |
limitation |
Applicable scenarios |
|
Seamless steel pipe |
High strength, no weld weaknesses |
High cost and long production cycle |
High-pressure boilers (such as power station boilers) |
|
Welded steel pipe |
Low cost and flexible specifications |
Welds are prone to corrosion and cracking |
Low pressure heating system |
Material classification: Which one is more suitable for your needs?
Carbon steel boiler tube: low cost, suitable for low temperature and low pressure environment below 400℃.
Alloy steel pipe (such as 15CrMoG): has very strong thermal strength and heat resistance (can withstand temperatures up to 550℃), while maintaining good mechanical properties and corrosion resistance. More suitable for industrial boilers.
Stainless steel pipe (such as 304/316L): strong corrosion resistance, suitable for chemical, shipbuilding and other environments that require corrosion protection.
Industry standard reference: When purchasing, please note that carbon steel must comply with ASME SA-192 standards and alloy steel must comply with SA-213 standards to ensure safety.
Common problems and solutions for boiler pipes
Corrosion and leakage
Causes: Water quality is too acidic (pH < 7), chloride ion corrosion, oxygen penetration.
Solutions:
1. Install a water treatment system to control the pH value of water quality to be between 8.5-9.5.
2. Apply epoxy resin coating or galvanized coating on the surface of steel pipes to extend the service life.
3. Regularly perform eddy current testing (ECT) on boiler tubes. Even if potential problems are found, the problem will eventually develop into a leak.
Scale and sediment
1. Chemical cleaning: Use chemical agents such as citric acid or EDTA to dissolve calcium carbonate scale.
2. Mechanical cleaning: For some difficult-to-clean sediments, a high-pressure water gun with a pressure of ≥3000psi can be used for cleaning.
Boiler Pipeline Professional Maintenance Checklist
Preventive maintenance can effectively extend the service life of boiler tubes. The following is a detailed professional maintenance checklist. It is recommended to follow the following steps regularly to ensure the efficient operation and safety of the boiler system.
1. Monthly inspection
Check whether the outer wall of the pipeline is rusted and bulged
Test whether the pressure relief function of the safety valve is normal
2. Quarterly maintenance
Water quality test (hardness, dissolved oxygen, pH value)
Clean the filter to prevent impurities from clogging the pipeline.
3. Annual overhaul
Use ultrasonic thickness gauge to detect the thickness of the pipe wall. Replace if the loss is ≥20%;
Full chemical cleaning, refer to the “Boiler Chemical Cleaning Rules” (TSG G5003).
FAQs：
1.How often do boiler pipes need to be replaced?
It depends on the use environment. Usually carbon steel pipes need to be replaced after 5-8 years of use at high temperatures, and alloy steel pipes can be extended to 10-15 years.
2.Can minor pipeline leaks be repaired by yourself?
High-temperature sealants can be used temporarily, but professional welders must be contacted for repair within 72 hours to avoid safety hazards!
