The present invention relates generally to systems for preventing the loss of fluid from a fluid circuit when a filter element located at a low end of the circuit is removed and more particularly relates to an automatic filter element shutoff valve.
In the past, when a filter element was removed from a low point in the fluid circuit, two manual valves, one on the inlet passage and one on the outlet passage, had to be closed in order to prevent fluid from being drained or siphoned out of the fluid circuit. When only one valve was closed, fluid would drain or siphon from the other passage resulting in a loss of fliud from at least a portion of the fluid circuit.
Further, when the new filter was put into place, it was necessary to remember to manually open both valves to avoid causing a catastrophic failure in other portions of the fluid circuit.