PURPOSE: To get the cleaning equipment of a feed oil pipe which is low-priced because it does not need any expensive sensors and the like and, in addition, reduces laborious manual operations as much as possible.

CONSTITUTION: A supply pipe 4, a pump 2, a feed oil pipe 3, a tank 1 and a delivery pipe 5 are communicated with one another respectively. A purge pipe 11 branches from the supply pipe 4. A sight glass 13 and a trap 12 are attached to the end of the purge pipe 11 via a valve 10. The trap 12 can discharge liquid, but can not discharge gas for its mechanism and, in addition, has a forced opening means of the trap, which is able to open the trap forcibly from the outside.