The line pipe is called "insulation electrician casing for building". Popularly speaking is a white hard PVC hose, anti-corrosion, anti leakage, pipe for wire wear. It is divided into plastic line pipe, stainless steel thread pipe and carbon steel tube.
It is used for indoor normal environment and places with high temperature, dust, vibration and fire hazard. It can also be used in wet places. It shall not be used in places especially humid, with acid, alkali, salt corrosion and explosive hazards.