180 Degree Elbow

180-degree bend use in the ammonia refrigeration system, an evaporator of many, such as cold storage evaporator calandria frozen between heavy use. Mainly to reduce the weld, reducing the normative leaks and standard installation. The two parallel tubes, not in the axis coincides, the 180-degree bend  seam one less than  two - welded - 90-degree elbows !