In the issuance of any bonds hereunder the state finance committee shall have due regard to the cost of operation and maintenance of the steam electric utility as acquired, constructed or added to, and to any proportion or amount of the revenue previously pledged as a fund for the payment of revenue bonds. It shall not require to be set aside into the fund a greater amount or proportion of the revenue than in its judgment and as agreed to by the director will be available over and above the cost of maintenance and operation and any amount or proportion of the revenue so previously pledged. Revenue bonds and interest thereon issued against such fund shall be a valid claim of the holder thereof only as against the fund and the proportion or amount of the revenue pledged thereto, but shall constitute a prior charge over all other charges or claims whatsoever against the fund and the proportion or amount of the revenues pledged thereto. Each revenue bond shall state on its face that it is payable from a special fund, naming the fund and the resolution creating it.