As light tight oil continues to increase in availability, refiners are challenged with how best to process this unique type of crude oil. With a much higher amount of naphtha and lighter materials in tight oil, the pre-flash step takes on increasing significance in the crude unit. This presentation will compare two types of pre-flash – a simple drum with vapor further refined in the crude tower, and a full pre-flash fractionator, where on-spec light naphtha products can be made and bypass the unit’s crude tower. The choice for an individual refinery is dependent on many factors. Advantages and disadvantages of each will be explored, and factors to consider in making a selection will be presented. Burns & McDonnell has significant experience with pre-flash designs in crude units and specific examples will be given to provide a clear understanding.