Fuel additive metering system

A valve device for controlling the rate of flow increase of a fluid media comprising:

• a) a valve body having an inlet, an outlet and an opening adopted to accept a flow restricting member positioned between said inlet member and said outlet member, said inlet and said outlet defining a flow path for said fluid media;
• b) a spring biased flow restricting member positioned within said opening and movable relative to said flow path between open and closed positions in response to changes in pressure of said fluid media, said flow restricting member being biased into a closed position, said flow restricting member having closure means for closing said opening and preventing flow from said inlet to said outlet, said flow restricting member being further comprised of fluid control means projecting into said opening on the inlet side for controlling fluid flow, said fluid control means including variable rate flow channel means to vary the flow of fluid past said opening depending on the degree of opening of said fluid restricting member, and
• c) a hydraulic dash pot assembly comprising a compression chamber and a piston with dual one-way check valves facilitating instantaneous closure of said flow restricting member housed therein, said assembly operatively associated with said flow restricting member and including means for selectively adjusting said hydraulic dashpot assembly consisting of a throttle valve adjustable manually by a control knob for selective variation of the flow of hydraulic fluid from said chamber to control the rate of opening of said flow restricting member with respect to said flow path.