Porous valve assembly

A valve assembly for controlling the flow of a predetermined fluid, comprising:

• a tube having an open end forming an outlet port of the valve assembly, and wherein the tube is made of a material that is porous with respect to the predetermined fluid;
• an outer wall forming a fluid chamber coaxially surrounding the porous tube and including an inlet port of the valve assembly;
• a valve member made of non-porous material with respect to the predetermined fluid and received for sliding movement within the porous tube, wherein sliding movement of the valve member within the tube and towards the open end of the tube reduces flow of the predetermined fluid from the fluid chamber, through the porous tube and through the outlet of the valve assembly, while sliding movement of the valve member within the tube and away from the open end of the tube increases flow of the predetermined fluid from the fluid chamber, through the porous tube and through the outlet of the valve assembly;
• and
• an actuator connected to the valve member for causing sliding movement of the valve member within the porous tube.