Interstage casing for a pump made of sheet metal and method of manufacturing the same.

摘要

An interstage casing made of sheet metal includes a cylindrical receptacle-like body having a bottom wall (24) on an end thereof and an open end opposite to the end. The open end has an axial end surface (22) and a radially inner surface (23) which serve as a member of a spigot joint to be joined to a next interstage casing. The cylindrical receptacle-like body also includes a cylindrical side wall (21), a cylindrical portion (25) joined between the bottom wall (24) and the cylindrical side wall (21) and having an outside diameter slightly smaller than an inside diameter of the open end, and a flat portion (27) joined to the recessed portion (26) and serving as an end surface of the bottom wall (24). The flat portion (27) is adapted to be engageable with the end surface of the open end of an adjacent interstage casing. The flat portion (27) has an outside diameter slightly larger than an outside diameter of the open end. The interstage casing further includes a recessed portion (26) joined to the cylindrical portion (25) and smaller in diameter than the cylindrical portion. The recessed portion provides a space for installing an O ring (31) therein.