UNIT OF FILTRATION (VERSIONS), UNDERGROUND STRUCTURE FORMED WITH UNITS OF FILTRATION, AND METHOD FOR MANUFACTURING OF UNDETACHABLE UNIT OF FILTRATION Russian patent published in 2009 - IPC E03F1/00 

FIELD: construction.

SUBSTANCE: invention is related to the field of sanitary engineering. Unit of filtration made of plastic, comprises body in the form of substantially rectangular parallelepiped having pairs of opposite first, second and third external surfaces, passing through unit of filtration at least one inspection channel with holes arranged at opposite third external surfaces of filtration unit. At the same time area of each hole in inspection channel makes at least 10% of third external surface area, in which it is provided. Method for manufacturing of undetachable element of filtration unit, in which form is used, comprising one or more rods, which create at least one section of inspection channel of filtration unit element, multiple rods, creating mentioned channels, passing parallel to channels, passing between each first external surface and one or several inspection channels of filtration unit element, and between each second external surface and one or several inspection channels of filtration unit element.

EFFECT: invention provides for device simplicity and reliability.

22 cl, 11 dwg