is a pipe made of high density polyethylene body which is hose shaped and its inner color is usually yellow and polished. The main use of these pipes is to collect and transfer water or sewage. This double-walled corrugated pipe, which is also known as polyethylene sewer pipe, is produced from polyethylene raw materials with grade EX3 - HDPE80 or HDPE100, from size 110 mm to 3500 mm.Carogit pipes have two outer walls with the appearance of grooved or concave grooves to strengthen the pipe against overhead soils and to bear dead and live loads from the ground. The inner wall is mostly yellow in color, which has a perfectly smooth and polished surface. It is used to transport sewage, acidic, alkaline and industrial effluents, and even to transport seawater and rivers by gravity.The size of corrugated pipe is in millimeters and in some cases it is inches and it is as follows. Exactly the same size can be produced in the drain pipe. Because in order to produce double-walled polyethylene drainage pipe, first the pipe is produced and then drilling is done by CNC machine.