Liquid and solid particulate contaminants in a compressor inlet gas stream can severely damage the compressor. Similarly, oil and other liquids that enter a compressor outlet stream can damage downstream process equipment and can also result in pipe corrosion. Although various separation technologies are currently available that will remove liquids and solids from a gas-dominated flow with some degree of efficiency, it is not clear which technologies best address different circumstances. Perhaps, in some instances, more than one type of filtration device is required. It is proposed here that in most of the filtration systems based on purely mechanical means of separating liquids and solids from a gas-dominated flow, the design process can be reduced to considering the following five basic processes or devices: gravity, vanes, wire mesh pads, cyclones, and fiber filter media. The Gas Machinery Research Council (GMRC) initiated a project with the intent to develop a comprehensive set of guidelines for the selection of filtration equipment to protect gas compression equipment from ingesting dangerous quantities of liquids and solid particulates. This report covers the first phase of the overall project in which the current industry needs and the state of industry guidelines are investigated.