We herein apply a mathematical method for detection of the outliers in experimental phase equilibrium data of ethylene/triethylene glycol (EG/TEG) solubility in a gaseous system. Four Chrastil-type correlations including the original Chrastil, Adachi and Lu, del Valle and Aguilera, and Mèndez-Santiago and Teja are used to represent/predict the phase equilibria of the EG/TEG + carbon dioxide/methane systems. It is found that the employed correlations are statistically valid, one experimental solubility datum from the solubility data of the carbon dioxide + EG system might be doubtful, two data points may be referred to be the outliers evaluated by the Mèndez-Santiago and Teja correlation and one data point from the same dataset is found to be out of applicability domain of the Adachi and Lu and the Mèndez-Santiago and Teja correlations.