Trap for catch basins and process of making same

A trap for mounting in a catch basin having a side wall with a cylindrical opening provided through the side wall, the trap comprising:

• a front plate member with an outlet opening located in an upper portion thereof and having a flange portion for engaging an outer surface of the side wall;
• a rear plate member with an inlet opening located in a lower portion thereof;
• and
• a connecting member extending between and connecting said front plate member and said rear plate member such that said plate members are spaced apart from each other and the lowest point of said outlet opening is higher than the highest point of said inlet opening,
• said rear plate member being circular and having an outer diameter close to, but not exceeding, the diameter of the cylindrical opening, said rear plate member and said connecting member being arranged such that said rear plate member and said connecting member can be inserted into the cylindrical opening from an outside of said catch basin in order to mount the trap in the side wall, wherein when said trap is mounted in the side wall, liquid leaving said catch basin through the cylindrical opening must pass through said inlet opening and then through said outlet opening and said flange portion engages the outer surface of the side wall.