The spray foam machine, or proportioner, does exactly that: proportions the chemical components to begin the process of manufacturing spray foam. The machine evenly proportions the chemical components by keeping them in an optimal 1:1 ratio by volume (called being “on-ratio”). It also heats the components to their required temperature range, which can be somewhere in the neighborhood of 120 degrees F, and transports them through hoses to the spray gun. The chemical components are kept separate through this entire process. The proportioner is comprised of a number of components, such as electric motors, metering pumps, pre-heaters, electric consoles, pressure switches and gauges.