Backflow is caused by cross-connections in the pipeline when pressures or flow rates fluctuate, resulting in the flow direction being reversed. Without a backflow preventer, this fluctuation in flow has the potential to allow contaminants to flow back into the original storage. With a backflow preventer (or foot valve) installed in the pipeline, when the fluid flows backwards, the pressure causes the valve to shut, preventing potential contamination. Foot valves can only be installed where the flow is intended be reversed, as the valve will close when the flow is reversed. In certain circumstances, foot valves can be installed vertically, although it depends on the size of the pipe, flow rates and the operating pressure. Contact our team for more information!