double tube

例句：

1. 1.The engineer designed a double-walled pipe to prevent leaks.
   工程师设计了一根双层管道以防止泄漏。
2. 2. The double-walled pipe was made from high-quality steel and had a long lifespan.
   这种双层管道是由优质钢材制成的，具有很长的使用寿命。
3. 3. The double-walled pipe is commonly used in oil and gas pipelines to reduce the risk of corrosion.
   双层管道在石油和天然气管道中被广泛使用，以减少腐蚀的风险。