Abstract: Due to differences in properties and fluctuations in tile hydraulic performances of crude oil and refined products in hatching operations,studies should be made of the complex process of the operational performances in the pump stations before making the pipeline design.The guiding principles of technological designs involving reasonable methods of transportation and regulation etc.are then determined.The concept of "cycle working range" is used in this article in the analysis of hydraulic performances.The amount of interface produced in batching products line presents some statistical features.Mastery of these features can guide the distribution and treatment of the mixture.By utilizing the formulas commonly employed very accurate results may be obtained in the calculation of the amount of interface,but the effects caused by batching operations are not considered in those formulas.Some examples cited in this paper explain the cases in details.