A seal comprises a lid that is rotary-mounted to a filter container base and has a body with at least two stub pipes and an internal part attached to the body in which are formed circulation ducts positioned as an extension of the stub pipes in opened position, and at least one bypass duct connecting the stub pipes in closed position. The internal part is attached to the body using a rotary bayonet mount by rotating to closed position in which the stub pipes are connected by the bypass duct, and the body together with the attached internal part are attached to the base using a rotate-and-lock bayonet mount. In closed position the internal part is attached to the base in a stationary manner using a longitudinal head joint formed on the joined elements, and the changing to opened position occurs by rotating the body in the rotate-and-lock bayonet mount.