The director of finance shall have the responsibility of making the budget transfers in the budget and maintaining the necessary individual records to assure each contributing fund the availability of funds for the replacement of or the acquisition of new municipal equipment which is needed once it has been depreciated or written off. Expenditures for the purchase or replacement of equipment shall be expended only to the degree of that particular department’s capital interest in the fund. (1957 code § 1.36.180.)