Clean and dredge all underground drainage pipe, floor traps & sewerage pits.
酒店内建筑及所有场地的地下管道、地漏和阴井的清理、疏通。
2
Brief: The pipe line is needed to dredge when it was blocked. It is very dirty and dangerous and lower efficiency or can not operate by manpower when the pipe line is waste or poisonous.