The Department may provide by resolution for the issuance of revenue refunding bonds of the State for the purpose of refunding any revenue bonds issued under this chapter or any prior law and then outstanding. The issuance of such revenue refunding bonds, the maturities and other details thereof, the rights of the holders thereof and the duties of the State and of the Department in respect to the same shall be governed by the foregoing provisions of this chapter insofar as the same may be applicable. No revenue refunding bonds shall be issued unless issued to refund revenue bonds which have matured or will mature within 3 months, or unless issued to refund revenue bonds which are redeemable within 3 months, and the interest rate of the revenue refunding bonds shall be at least one fourth of 1 percent less than the interest rate borne by the revenue bonds so refunded. If the revenue refunding bonds do not mature prior to the earliest date of maturity of the revenue bonds refunded and the principal amount of such revenue refunding bonds maturing in any year does not exceed the principal amount of revenue bonds so refunded which would have matured in such year, such revenue refunding bonds shall rank on a parity with the revenue bonds then outstanding, shall be deemed to be of the same issue and shall be entitled to payment from the same fund without preference or priority of the outstanding revenue bonds.