A device for filtration with a set of least one filter cassette comprising: - a manifold providing fluid connection and mechanical connection comprising at least one flow inlet for a fluid to treat, at least one flow outlet for a treated fluid and a network for conveying said fluid to treat and said treated fluid, said manifold having two bearing surfaces (222, 223) each for a said filter cassette and arranged on respective opposite first side and second side of said manifold through which bearing surface (222, 223) emerge cassette feed ports and cassette return ports communicating with said conveying network, which cassette feed ports and cassette return ports are configured to communicate with conduits formed in a said filter cassette bearing against said bearing surface (222, 223); - two clamping plates (204, 234) each facing a respective bearing surface (222, 223); and - means for driving and guiding said clamping plates (204, 234) parallel to and facing said bearing surfaces (222, 223), that are formed by rods (106; 206, 266) which extend between said manifold and said clamping plates (204, 234) and by at least one actuator, which is provided with a body and a member moveable relative to said body, which moveable member has an extended position and a retracted position in which said moveable member has been moved through a predetermined travel relative to its extended position, by virtue of which both clamping plates (204, 234) have a starting position in which said plates (204, 234) are away from said set of at least one filter cassette and a clamped position in which said plates (204, 234) are approached and compresses said set of at least one filter cassette against said manifold; characterized in that said body of said actuator is movably mounted in a sleeve fixed to said manifold; said moveable member carries said rods (206, 266); and said at least one actuator, said rods (206, 266) and said clamping plates (204, 234) are configured such that said at least one actuator drives both clamping plates (204, 234) via said rods (206, 266) to the clamped position in which said moveable member (53; 253) is in an intermediate retracted position in which said moveable member (53; 253) has moved through a shorter travel than said predetermined travel relative to its extended position. - a manifold providing fluid connection and mechanical connection comprising at least one flow inlet for a fluid to treat, at least one flow outlet for a treated fluid and a network for conveying said fluid to treat and said treated fluid, said manifold having two bearing surfaces (222, 223) each for a said filter cassette and arranged on respective opposite first side and second side of said manifold through which bearing surface (222, 223) emerge cassette feed ports and cassette return ports communicating with said conveying network, which cassette feed ports and cassette return ports are configured to communicate with conduits formed in a said filter cassette bearing against said bearing surface (222, 223); - two clamping plates (204, 234) each facing a respective bearing surface (222, 223); and - means for driving and guiding said clamping plates (204, 234) parallel to and facing said bearing surfaces (222, 223), that are formed by rods (106; 206, 266) which extend between said manifold and said clamping plates (204, 234) and by at least one actuator, which is provided with a body and a member moveable relative to said body, which moveable member has an extended position and a retracted position in which said moveable member has been moved through a predetermined travel relative to its extended position, by virtue of which both clamping plates (204, 234) have a starting position in which said plates (204, 234) are away from said set of at least one filter cassette and a clamped position in which said plates (204, 234) are approached and compresses said set of at least one filter cassette against said manifold;