A210C internally threaded seamless steel pipe for high-pressure boilers is a key material widely used in power station boilers and high-pressure industrial equipment. Its key points for use need to be comprehensively controlled from aspects such as material properties, installation requirements, operation and maintenance, and safety specifications to ensure the safe and efficient operation of the equipment. The following are specific key points for use:

First, material properties and scope of application
1. Material Standard: A210C steel grade complies with the ASME SA-210 standard and belongs to medium-carbon manganese steel. The chemical composition is strictly controlled (such as C≤0.35%, Mn 0.29~1.06%), with high strength, high toughness, and good thermal conductivity. The internal thread design improves heat transfer efficiency by increasing fluid disturbance and is suitable for high-pressure boiler water-cooled walls, economizers, and other heating surfaces.
2. Performance parameters: tensile strength ≥485MPa, yield strength ≥275MPa, elongation ≥30%, hardness ≤89HRB, ensuring stability under high temperature and high pressure environments. The recommended operating temperature range is 400~500℃, which is suitable for components such as reheaters and economizers with operating temperatures less than 500℃.

Second, key points for installation and welding
1. Inspection before installation
(1) Appearance inspection: Ensure that the steel pipe has no defects such as cracks and sand holes, and the size meets the design requirements.
(2) Material verification: Check the material certificate to ensure that it meets the A210C standard.
2. Welding process: Use argon arc welding (GTAW) or argon arc welding primer + manual arc welding (GTAW+SMAW) capping process, and select matching welding materials (such as H08Mn2SiA, H05MnSiAITiZrA). The welding groove angle is 35°±1° to ensure the quality of the weld and avoid cracks or breaks.
3. Flaw detection: Perform 100% non-destructive testing (such as ultrasonic flaw detection and magnetic particle flaw detection) after welding to ensure that the weld is defect-free.

Third, operation and maintenance specifications
1. Operation parameter control:
(1) The working pressure and temperature shall not exceed the design value to prevent deformation or rupture caused by overpressure and overtemperature.
(2) Avoid long-term operation in the blue-brittle temperature range of about 250℃ to prevent brittle fracture.
2. Daily maintenance
(1) Regularly inspect the pipeline surface to promptly detect and deal with corrosion, wear, and other problems.
(2) Keep the environment around the pipeline clean to avoid damage by debris.
3. Heat treatment and pipe bending
(1) When bending the pipe, the ratio of the bending radius R to the outer diameter D should be ≥2 (cold bending) or ≥1.25 (hot bending), otherwise heat treatment is required.
(2) The heat treatment system must meet the standards (such as 900~930℃ normalizing + tempering) to ensure stable performance.

Fourth, safety specifications and precautions
1. Storage and transportation
(1) Store in a dry and ventilated place to avoid moisture and corrosion.
(2) Avoid contact with sharp objects during transportation to avoid scratches.
2. Corrosion protection
(1) Select appropriate anti-corrosion measures (such as coating, and cathodic protection) according to the characteristics of the medium.
(2) Regularly treat water quality to prevent scaling and corrosion.
3. Emergency treatment
(1) Develop emergency plans for leakage, overpressure, etc. to ensure rapid response.
(2) Conduct safety drills regularly to improve the emergency response capabilities of operators.

Fifth, quality inspection and acceptance
1. Factory inspection
(1) Conduct mechanical properties (tensile, impact), metallographic structure, non-destructive testing, and other inspections according to standards.
(2) Internal thread size, surface roughness, etc. must meet design requirements.
2. On-site acceptance
(1) Check whether the appearance, size, and marking of the pipe meet the requirements.
(2) Check the quality certificate to ensure that the material is traceable.

Sixth, advantages
1. The internal thread design increases the heat transfer efficiency by more than 30% and reduces energy consumption.
2. High strength and toughness adapt to high pressure and high temperature environments and extend the life of the equipment.

Seventh, Summary of Precautions
Installation stage: strictly control the welding process to ensure weld quality.
Operation stage: regularly monitor pressure and temperature to avoid over-limit operation.
Maintenance stage: timely handle corrosion, wear, and other problems to prevent accidents from expanding.