Patent Number: 054266793
Section: abstract

A strainer device for filtering water to an emergency cooling system in a nuclear power plant containment area having a lower part which forms a pool in which the strainer device is mounted. The device includes a strainer housing with separate strainer walls between which a flexible strainer means operates. The unit is arranged to be kept in a first position when water is drawn through one of the strainer walls, in which position it interrupts the connection between the other strainer wall and a suction conduit. By inherent flexibility, a shield means is automatically switched over to a second position which opens the connection between the second strainer wall and the suction conduit, as soon as the first strainer wall is clogged by impurities to such an extent that a low-pressure arises in the space between the first strainer wall and the shield means unit, which low-pressure brings about the switching-over by its suction effect.