The food industry, for having powdery products as raw material, faces several obstacles in the design of silos to store these products. For this reason, the adequate sizing of the storage silo for pulverulent products becomes indispensable for this sector specifically. With this in mind, the present work designs the discharge orifice for rice and corn starch and potato and cassava starches based on the flow properties obtained by the Jenike Shear Cell and the Powder Flow Tester so that the design is as mechanically and economically efficient as possible. The flow properties found in the two shear tests were compared with the Australian (AS, 1996) and European (Eurocode 1 - BS, 2006) international standards, and it was found that, the shear test performed in the Powder Flow Tester presented mainly the values of effective friction angle and friction angle with the wall within the standardized value for wheat flour. The calculation of the discharge orifice was only possible for cassava and potato starch in the Powder Flow Tester, however, presenting values that would lead to undersizing.