The objective of the paper was to assess the impact of technical efficiency of two types of anti-drop valves on the intensity size of the liquid outflow from slotted atomizers. The paper presents research on two types of valves of a varied structure. Used, single filter-valves with anti-drop valves and an atomizer body equipped with membrane valves constituting their integral part were investigated. The research was carried out on a stand that serves for measuring the liquid outflow intensity from agricultural atomizers. The value of valves opening pressure, closing pressure and the liquid outflow intensity were investigated in four variants: A – orifice of 6 mm diameter, B – atomizer of 02 size, C – atomizer of 03 size and D – atomizer of 04 size. It was also determined that valves of individual filter-valves proved variable values of pressures during their opening and closing and a variable size of the liquid outflow. Membrane valves were characterized with high stability of the opening and closing pressure and the intensity of the liquid outflow.