Combination fuel filter and water separator

Claim 1

A filter and water separator for lighter-than-water fluid, comprising: a frame; a fluid inlet connected to the frame; a circular lower chamber communicating directly with and positioned below the inlet, the inlet being disposed tangentially to the lower chamber such as to induce a swirling, arcuate flow to the fluid to separate out water and particulate material from the fluid centrifugally so that they settle at the bottom of the lower chamber, and further including a ramp-like conduit extending generally helically into the lower chamber from the inlet, on a downward angle, for imparting a helical flow path and downward component to the motion of the incoming fluid, to aid in settling of material in the lower chamber; an upper chamber above the lower chamber; a divider between the lower and upper chambers with a check valve therein, downstream of the lower chamber and upstream of the upper chamber and oriented to pass fluid only from the lower to the upper chamber, after such fluid has had said water and particulate material settled out in the lower chamber; a generally circular open-bottomed flow shield collar extending downwardly from the frame part way into the lower chamber, just inside the helical flow path of the incoming fluid and surrounding the check valve, so that the helically moving incoming fluid is isolated from the check valve initially, then flows up into the space defined by the collar and through the check valve; a fluid outlet connected at a downstream end of the upper chamber; a filter element in the upper chamber, positioned between the check valve and the fluid outlet in the path of fluid flow; and access means for opening the upper chamber to service the filter element; whereby particulate material and water may be separated out of the fluid while it swirls at relatively low velocity in the lower chamber, before the fluid flows through the check valve, which would otherwise be subject to fouling by the particulate material, and the check valve prevents outflow of fluid from the chamber by gravity when the access means is opened.