Uzbekistan is implementing comprehensive measures to produce a wide range of high-quality and inexpensive textile and light industry products based on the production and deep processing of cotton fiber, which is the main textile raw material, to prevent waste and increase its competitiveness. This article, to a certain extent, serves to implement the tasks specified in the Decree of the Cabinet of Ministers dated November 25, 2018 No. 53 “On additional measures to organize the activities of cotton and textile industries and clusters” and other regulatory and legal documents related to this activity. The science of cotton transport by pneumatic transport has a long history, and with an air flow speed of more than 28 m/s, cotton is distributed more evenly over the pipe section. In it, the transportation process is carried out mainly in the suspended state of the material. With a decrease in the air flow velocity from 25.0 m/s, an analysis of the literature on the uneven distribution of material over the pipe section was carried out. It has been practically proven that an increase in the expansion angle in expanding or contracting pipes depends on air resistance, and the expansion or contraction angle depends on the speed of air movement at the point of expansion or contraction of the pipe. Therefore, the optimal value of the angle of expansion or contraction of expanding or contracting pipes was determined.