Titanium seamless tube is a highly preferred material for heat exchangers and condensers due to its perfect physical and chemical properties. GB 3625-83 provides the specification of titanium seamless tubes used in heat exchangers and condensers.
Titanium is a metal material that is widely used in the industry today due to its remarkable advantages; it has outstanding strength, superior corrosion resistance, and superior heat transfer performance. From this perspective, titanium is the optimal choice for heat exchangers and condensers used in the industry. Because the core of the heat exchanger is the seamless titanium tube, it is particularly important to have the correct specification of the titanium tube. According to GB 3625-83, the requirements for titanium seamless tubes used in heat exchangers are as follows:
1. The material is grade 1 titanium, whose chemical composition is determined according to GB/T 3621-2007.
2. Dimensional range of seamless titanium tubes for heat exchangers and condensers: outer diameter 6.0mm to 114.3mm, and wall thickness 0.5mm to 10.0mm;
3. The outer surface of the titanium seamless tube must be free of oil, grease, and other organic matter on the surface. It should be heated to 220-240℃ and descaled one by one within 60s ~ 90s, and cooled down to ≤70℃;
4. The straightness of titanium seamless tubes for heat exchangers should not be greater than 0.5mm/m;
5. No nitrate or weld defect is allowed on the inside or outside surface of the titanium seamless tube, and there should be no significant defects or obvious disorderly phenomena;
6. The surface roughness of the titanium seamless tube should be Ra ≤ 0.8M, and the tubes should be polished, pickled and passivated.
In summary, titanium seamless tubes for heat exchangers, as stipulated in GB 3625-83, must have a specific material grade, dimensional range, cleanliness and straightness, as well as free from weld faults and nitrate. The surface roughness of titanium seamless tube should also be Ra ≤ 0.8M.
