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.
起下钻需要频繁制动，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年以来，世界钢管产量总体上呈下降趋势，但钢管生产技术仍取得了长足的进步；
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：本文针对棒式毛坯轧制的特点，设计制造了一种斜轧精密自动下料机，并介绍了整机和主要部件的结构。