Q: What is the weight calculation formula for seamless steel pipes (taking 20# steel as an example)?
A: The weight per meter (kg/m) = 0.02466 × (outer diameter - wall thickness) × wall thickness. For example, a 20# seamless pipe with outer diameter 108 mm and wall thickness 4 mm: 0.02466 × (108 - 4) × 4 ≈ 10.26 kg/m.
Q: What is the difference between ASTM A312 TP304 and TP316L seamless steel pipes?
A: Both are austenitic stainless steel. TP316L adds molybdenum (Mo) on the basis of TP304, which has better corrosion resistance to chloride ions and dilute acids. TP316L is more suitable for corrosive environments such as marine and chemical industries.
Q: What is the maximum service pressure of GB/T 8163 20# seamless steel pipes with outer diameter 159 mm and wall thickness 6 mm?
A: According to the formula P = 2σS/D (σ is the allowable stress of 20# steel, S is wall thickness, D is outer diameter), the maximum service pressure is about 10 MPa (under normal temperature conditions), which can be adjusted according to the actual service temperature.
Q: What grade of seamless steel pipe is used for the main pipeline of thermal power plants?
A: ASTM A335 P91, P22 or GB/T 5310 12Cr1MoVG seamless steel pipes are used. They have excellent high-temperature resistance and pressure resistance, which can adapt to the high-temperature and high-pressure working conditions of thermal power plant boilers and steam pipelines.
Q: Can seamless steel pipes of API 5L X52 be used in buried pipelines?
A: Yes. After anti-corrosion treatment (such as 3PE anti-corrosion layer) and cathodic protection, API 5L X52 seamless steel pipes can be used in buried oil and gas pipelines, which can effectively prevent soil corrosion and extend the service life.
