Ecology fuel return systems

Abstract

A shut-off valve includes a float and a negative G control component. The float is configured to occlude a tank outlet at a first fluid level and 1 G and unocclude the tank outlet at a second fluid level and 1 G. The negative G control component is operatively connected to the float to limit fluid, e.g. liquid or gas, communication between a tank outlet and an ejector pump during negative G events. An ecology fuel return system includes a tank, an ejector pump, a float, and a negative G control component, as described above. The tank has an inlet and an outlet. The inlet is configured to be in fluid communication with components of an engine. The ejector pump is in fluid communication with the tank outlet and is configured to pump fuel from the tank to a fuel pump inlet of an engine.

What is claimed is: 
     
         1 . A shut-off valve comprising:
 a float configured to occlude a tank outlet at a first fluid level and 1 G and unocclude the tank outlet at a second fluid level and 1 G; and   a negative G control component operatively connected to the float to limit fluid communication between a tank outlet and an ejector pump during negative G events.   
     
     
         2 . A shut-off valve as recited in  claim 1 , wherein the negative G control component includes a slosh plate disposed proximate to the float surrounding at least a portion of the float, wherein the slosh plate is configured to concentrate fluid between the slosh plate and the float during a negative G event to damp a displacement of the float against a negative G event force. 
     
     
         3 . A shut-off valve as recited in  claim 2 , wherein a surface area of the slosh plate between a top of the float and the slosh plate is smaller than a collection area of the slosh plate. 
     
     
         4 . An ecology fuel return system, comprising:
 a tank having an inlet and an outlet, wherein the inlet is configured to be in fluid communication with components of an engine for recovery of fuel;   an ejector pump in fluid communication with the outlet of the tank, wherein the ejector pump is configured to pump fuel from the tank to a fuel pump inlet of an engine;   a float configured to occlude a tank outlet at a first fluid level and 1 G and unocclude the tank outlet at a second fluid level and 1 G; and   a negative G control component operatively connected to the float to limit fluid communication between the tank inlet and the ejector pump during negative G events.   
     
     
         5 . An ecology fuel return system as recited in  claim 4 , wherein the negative G control component includes a slosh plate operatively connected to the tank between the inlet and the float, wherein the slosh plate is configured to concentrate fluid between the slosh plate and the float during a negative G event to damp a displacement of the float against a negative G event force. 
     
     
         6 . An ecology fuel return system as recited in  claim 5 , wherein a surface area of the slosh plate between a top of the float and the slosh plate is smaller than a collection area of the slosh plate at a bottom of the tank.