Abstract: Self-supporting structure comprising a monobloc for installing cylindrical filtration cartridges therein. In one embodiment a structure provides two side panels on each side of the monobloc used for sealing the numerous passageways, at the same time, provided within the monobloc. Such a structure aims to sharply reduce the number of components required to install cylindrical filtration cartridges in a filtration plant, while keeping the same number of cartridges. Thus the invention contributes to highly reduce the investment and the maintenance costs of a filtration plant, and offers also the opportunity to reduce the operational cost of such a plant.