The invention concerns a filtration device comprising a manifold providing fluid connection and mechanical connection comprising a clamping plate movably mounted relative to the manifold and adapted to compress at least one cassette against the manifold, means for driving and guiding the clamping plate comprising a rod extending between the manifold and the plate, an actuator provided with a body and a member moveable relative to the body, which member is adapted to move through a predetermined travel between an extended position and a retracted position, the body being carried by the manifold, and the member carrying the rod and driving the plate via the rod to a clamped position in which the member is in an intermediate retracted position in which it has moved through a shorter travel than the predetermined travel relative to its extended position.