tubing elevator造句

• Abstract : discuss a technique of oil tube elevator , introduce the constrution , principle , and safety of the new oil tube elevator latcher , and analyse the economic benefit and the apply prospect of the oil tube elevator with the exchangeable erescent elevator recess
  文摘:介绍了新型吊卡销的结构和原理与安全性，剖析了可更换小月牙式油管吊卡的经济效益和推广应用前景。