Correctly selecting and using 15CrMoG boiler steel tubes requires attention to several key stages: selection, installation, operation, and maintenance.
First, what should be considered during the selection stage of 15CrMoG boiler steel tubes?
(a) Based on operating parameters: Accurately consider parameters such as boiler operating temperature, pressure, and medium composition. If the operating temperature is consistently between 500-550℃, the pressure is in the medium-high pressure range, and the medium is not highly corrosive, 15CrMoG boiler steel tubes are an ideal choice. This is because their alloy composition ensures creep resistance and oxidation resistance within this temperature range, maintaining pipe strength and stability, and resisting steam pressure. If the operating temperature exceeds 550℃, higher-grade heat-resistant alloy tubes must be evaluated.
(b) Matching Pipe Diameter and Wall Thickness: Determine the appropriate pipe diameter based on steam flow requirements. Use the flow calculation formula to calculate the ideal pipe diameter to meet the conveying capacity. Then, according to the pressure value to be withstood, refer to the corresponding standards for pipe pressure wall thickness to select an appropriate wall thickness to ensure the pipeline can withstand internal pressure and prevent the risk of bursting.
(c) Quality Control: Prioritize products from reputable large steel mills. Check whether the products come with complete quality certification documents, such as material analysis reports, mechanical property test reports, and non-destructive testing results, to ensure that the initial quality of the pipes meets standards.
Second, what are the details of the installation stage of 15CrMoG boiler steel pipes?
(a) Pipeline Pre-treatment: Before installation, conduct a comprehensive inspection of the 15CrMoG boiler steel pipes, checking for defects such as cracks, sand holes, and heavy scale on the surface; clean the inside of the pipes of debris, rust, and oil stains to maintain cleanliness; perform necessary straightening of the pipes to ensure that the straightness meets the installation requirements and reduce the risk of subsequent stress concentration.
(b) Welding Key Points: Due to its alloying elements, preheating within the range of 150-200℃ is required before welding to slow down the cooling rate and avoid the formation of hardened structures. Use matching heat-resistant steel welding rods, such as R307 welding rods. Strictly control the current, voltage, and welding speed during the welding process. Immediately after welding, perform tempering treatment at 680-720℃ to eliminate welding stress and optimize the performance of the weld and heat-affected zone.
(c) Rationality of Installation Layout: The pipeline routing design should be scientific, avoiding sharp bends and frequent changes in direction to reduce unnecessary stress. Based on the principle of thermal expansion and contraction, reasonably reserve space for pipeline expansion and contraction, and add components such as expansion joints and bend compensators to prevent thermal stress damage to the pipeline.
Third, what details need to be maintained during the operation and maintenance phase of 15CrMoG boiler steel pipes?
(a) Start-up and Shutdown Procedures: When starting the boiler, the temperature and pressure should be increased slowly to allow the pipeline buffer time to adapt to temperature and pressure changes, for example, controlling the heating rate at 12℃/min; when shutting down, the temperature and pressure should be decreased slowly to avoid thermal shock.
(b) Regular Inspections: During operation, regularly inspect the pipeline appearance for deformation, leakage, and corrosion; monitor pipeline wall thickness using equipment such as ultrasonic thickness gauges to compare with the initial wall thickness and predict the degree of corrosion and wear; regularly perform flaw detection on welds in critical areas to identify potential welding defects.
(c) Water Quality Control: Given that boiler steel pipes are in long-term contact with steam and water, it is essential to ensure excellent feedwater quality. Remove impurities, dissolved oxygen, and hardness ions from the water to reduce the risk of scaling and corrosion, and extend the service life of the 15CrMoG boiler steel pipes.
Post time: Feb-03-2026