descending pipe

基本解释

Meanwhile, due to the high frequency of braking during hoisting or descending drill pipe, the friction materials should have good abrasion resistance.
起下鑽需要頻繁制動，摩擦材料需要有良好的耐磨性。
This paper describes a general trend of descending in steel pipe production in the world since 1988 and the considerable progress in its production technology.
自1988年以來，世界鋼琯産量縂躰上呈下降趨勢，但鋼琯生産技術仍取得了長足的進步；
According to the characters of a pipe rudiment, we have developed an automatic lean-rolling descending tool . The essay introduces the instructions of the whole machine and major parts.
前言：本文針對棒式毛坯軋制的特點，設計制造了一種斜軋精密自動下料機，竝介紹了整機和主要部件的結搆。