Revenue bonds issued under the provisions of this chapter shall not constitute a debt of the Commonwealth or a pledge of the faith and credit of the Commonwealth, but such bonds shall be payable solely from the funds provided from fees and charges. The bonds shall state on their face that the Commonwealth is not obligated to pay the bonds or the interest on them except from the special fund provided from fees and charges under this chapter, and that the faith and credit of the Commonwealth are not pledged to the payment of the principal or interest of the bonds. The issuance of revenue bonds under the provisions of this chapter shall not obligate the Commonwealth to levy or to pledge any form of taxation for the bonds or to make any appropriation for their payment, other than to appropriate available funds derived as revenue from fees and charges collected under this chapter.