LUBRICANT SPECIFICATIONS: PART SEVEN (a) TEMPORARY PROTECTIVES AND RUST INHIBITORS Available to Purchase

LUBRICATING OILS HAVE SECONDARY functions ; they are coolants, for example, while in certain types of crankcase oils the composition is such that solid carbon particles are held in suspension and the lubricant is a “detergent”. In many delicate mechanisms the lubricant is expected to protect bright metal surfaces from atmospheric attack ; this is an important aspect of a lubricant's duties and serves to introduce a subject of wide interest. It is tacitly assumed that lubricating oils and greases—in their original, unchanged condition—provide a natural protection for the metal surfaces of the machines that they service and when usage conditions are such as to interfere with the protective action the lubricants are modified so as to restore it. The intrusion of water into steam turbine oils and the inhibitors added to these lubricants illustrate this typo of situation.