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The specifications and material selection for heat exchange tubes must be determined based on comprehensive factors such as operating pressure, temperature, corrosivity of the medium, and heat exchange efficiency. The following is a summary of the key information: 1. Material Selection 1. Common metal materials Stainless steel: It has strong corrosion resistance (especially suitable for acidic/basic media), can withstand high temperatures (e.g., 321 stainless steel can reach 900°C), and possesses high strength. Common grades include 304 (for general corrosive media), 316 (for acidic/saline media), and 321 (for highly corrosive high-temperature environments). Copper and copper-nickel alloys: They have good thermal conductivity but poor corrosion resistance, making them suitable for use with clean fluids or in applications with high hygiene requirements. Carbon steel/low-alloy steel: low cost and high strength, but requires regular anti-corrosion maintenance; suitable for low-pressure, non-corrosive media. Titanium/aluminum alloy: Titanium is resistant to severe corrosion, while aluminum is lightweight and has good thermal conductivity, but it requires protective measures. 2. Non-metallic materials: graphite, ceramics, polytetrafluoroethylene, etc., suitable for extreme corrosive or high-temperature environments. II. Specifications 1. Size range: Outer diameter and wall thickness: Common outer diameters range from Φ12mm to Φ114mm, with wall thicknesses of 0.5–8mm; specific standards include JIS G3461, which specifies outer diameters of 15.88–76.3mm and wall thicknesses of 1.2–8mm. ASTM A179: Outer diameter 19.05–76.2 mm, wall thickness 1.2–8 mm. Tube length: Customizable, usually within 6m. 2. Selection criteria: Pipe diameter selection – Smaller diameters (such as Φ19mm×2mm) are suitable for clean fluids to enhance heat exchange, while larger diameters (such as Φ38mm×2.5mm) are used for viscous or scale-prone media. Nominal parameters: the inner diameter of the shell (DN400–DN800) and nominal pressure (1.0–2.5 MPa) must meet the requirements of the operating conditions. III. Additional suggestions: Balance between corrosion resistance and efficiency: Stainless steel is less affected by the oxidation layer over time, while copper pipes require attention to avoid efficiency losses caused by oxidation. Standard compliance: It is necessary to refer to standards such as JIS, ASTM, and DIN regarding the requirements for dimensional tolerances and material properties. For complete specifications or detailed model parameters, please refer to the relevant standard documents or manufacturer materials.