Old sewage systems discharging sewage from domestic water devices often become clogged along the sections running in the walls, e.g.. different kinds of lap. Access to them is difficult. To remove the blockage, you need to use the so-called. hydraulic spring. It is inserted into the installation through the nearest hole and the blockage is removed by turning the spring handle, at the end of which a brush or drill is attached. The spring will remove the biggest blockage.