A new efficient separator design has been developed with a string-type demister. The demister is made up of packets consisting of series of vertical fibers that are positioned parallel to each other. These demisters have been tested in semicommercial and commercial equipment in treating natural and associated gases. The test results showed that the capacity of the string-type demister, for a given separation, is five times that of demisters made of knit screen and approximately twice that of vane-type separators. These data were used in the reconstruction of more than 20 currently operating oil-gas separators by replacing knit screen demisters by string-type demisters.