Abstract: The after-expanding purging device failed to completely clear the large-sized SSAW pipe of the remaining oil and emulsion on its inner/outer surfaces as from the expanding process,and thus failed to meet the ex-works quality criteria of the pipe.Addressing the problem,the company has taken relevant technical measures to get the hard nut crushed,mainly including technical modification of the key components of the device,i.e., the purging head and the spray nozzles so as to get the purging quality of the pipes and the operation efficiency of the equipment enhanced.