Abstract: A closed type compressor having a closed casing, a compressor unit, and a motor enclosed in the casing together with the compressor unit. A copper pipe is mounted to the casing through a steel pipe joint for inducing or discharging a coolant to or from the compressor. The casing is comprised of a steel cylindrical wall which has an elliptical aperture in its wall, a top end wall, and a bottom end wall respectively closing the top and the bottom end openings of the cylindrical side wall. The pipe joint has a conical outer surface capable of meeting with the ellliptical aperture wall defining the elliptical aperture in the cylindrical side wall without leaving any gap between them. The pipe joint is coupled to the elliptical aperture wall of the cylindrical side wall by resistance welding.