Gas/liquid separation system

摘要

A gas/liquid separation system includes a cyclone case, a gas outflow pipe including a flange, and a housing that accommodates a valve and is welded to a peripheral edge portion of an upper opening of the cyclone case. An upper opening of a cylindrical portion of the cyclone case is blocked off by the flange of the gas outflow pipe. An annular projection is formed at the flange and at the housing. The annular projections fit together with an annular recess formed in the upper opening edge portion of the cyclone case. The gas outflow pipe and the housing are welded at the upper opening edge portion of the cyclone case. A sealing property can be secured without using seal members, and welding portions are few.