Section 17
SEC. 17. The determinations of the said Board shall be expressed in written orders, and proof thereof may be made by a copy of the same duly certified under the seal of the Board, by the secretary of the Board, or by any member of the Board designated for this purpose by the Board; and whenever any matter or preceding has certified as herein provided, shall be received in the courts and by every officer thereof in civil cases as prima facie evidence that such determination was legally made and was just right, proper and reasonable. All orders of the Board shall take effect within such reasonable time, not less than thirty days, and shall continue in force such period of time , not exceeding two years, as shall be prescribed in the order of the Board, unless the same shall be suspended or modified or set aside by the Board, or be suspended or set aside by a court of competent jurisdiction.