Abstract: A drain valve used on an at least partially dielectric container has a valve housing made of electrically nonconductive plastic, fixed to the container, and forming a passage opening into the container so that fluent contents of the container can flow out of the container through the passage. A valve body formed at least partially of an electrically conductive material is movable in the passage between a closed position blocking flow through the passage and an open position permitting flow through the passage. An actuating element outside the housing is connected to the body for shifting same between its positions.