METHOD FOR MAKING DOUBLE WALL GAS BELLOWS FOR INJECTING GAS FUEL OF SHIP

摘要

The present invention relates to a method for manufacturing a double pipe gas bellows for a fuel injection pipe of a ship minimizing changes in the outer diameter and inner diameter of a bending potion. To this end, the method comprises: a step of welding a first flange to an end part of one side of a first double pipe having a first inner pipe and a first outer pipe (a); a step of bending the first double pipe (b); a step of welding a second inner pipe to an end part of one side of an inner bellows, welding a third inner pipe to an end part of the other side of the inner bellows, and welding an end part of one side of a third outer pipe and an end part of one side of the third inner pipe with a second flange (c); a step of welding a second outer pipe to an end part of one side of an outer bellows and welding an end part of one side of the second inner pipe to an end part of one side of the first inner pipe (d); a step of welding an end part of one side of the first outer pipe and an end part of one side of the second outer pipe (e); and a step of welding an end part of the other side of the outer bellows to a third outer pipe.