To provide a drainage pit capable of reducing a construction cost, preventing the bad smell from a sewer by having a seal water trap function with high reliability for a long period of time in the case it is usually used, completely discharging stagnant waste-water containing impurities from the drainage pit in the case of cleaning and facilitating the cleaning of a detachable trap pipe with such a structure that unwanted bacteria cannot easily grow.
In the drainage pit consisting of a tank body, a basket placed in the tank body, a seal water trap placed in the tank body and connecting pipe for connecting the tank body to the sewer, the axis of a pipe axis of the connecting pipe has an angle of 30° to 70° to the vertical direction, and the end of the trap pipe having the outer circumferential surface contracted to a conical-shape is abutted on the connecting pipe having the inner circumferential surface contracted to the conical-shape in a detachable manner.
TABUCHI HIROSHI
HARA KEIJI
ITANI TAKAAKI
SHIMODA ECOTECH CO LTD