Presently, industry places heavy reliance on the use of chlorinated solvents to achieve acceptable levels of cleanliness for systems in oxygen service. The Montreal Protocol and other restrictions will prohibit the use of these types of solvents because of potential damage to the environment. This paper discusses some of the issues involved in assessing aqueous based cleaning agents. A gravimetric test procedure has been developed to have a standard method of comparing the ability of a cleaning agent to remove oil and grease contaminants from prepared metal coupons. Data is presented to demonstrate the results of the test procedure. The testing addresses the use of a soak method and ultrasonics. The effects of time and temperature are directly addressed. Other variables are discussed in general terms such as disposal and cost considerations.
Three contaminants were selected for evaluation: hydrocarbon oil, lithium grease, and Halocarbon grease. Some of these contaminants present potential hazards in oxygen systems. The test method allows a common method for evaluation of cleaning agents and verification of contaminant levels for oxygen systems. The test procedures can also be applied to general degreasing of metal components throughout industry.