The mechanism (14) supports the short length refractory outlet tube (16) and the long length refractory flow protectiontube (18) side by side.
该机构（14）并排支撑短尺寸耐火出口管（16） 和长尺寸耐火流动保护管（18）。
2
Vacuum distillation using the dropper with the exhaust port and the access protectiontube to prevent leakage of liquid directly into the vacuum pump.
减压蒸馏使用带抽气口和防护滴管的接液管，可以防止液体直接泄露到真空泵中。
3
This paper introduces successful construction method and control measure currently used for holedrill, borehole deviation, protectiontube, and embedment and installation of bimetal mark.