Method and apparatus for automatically stopping the process of filling of a tank with a liquid under gas or vapor pressure

An apparatus for filling a tank with a liquid, said apparatus comprising:

• i) a tank with an inlet;
• ii) a liquid supply capable of providing liquid at a pressure adequate to ensure flow of said liquid into said tank;
• iii) a fluid conduit connectable between said supply and said tank to allow fluid communication therebetween;
• iv) a tube permanently installed within said tank, said tube originating at said inlet and ending at a point in an imaginary plane coincident with the liquid surface which would exist in said tank if said tank were filled with said liquid to the maximum allowable extent;
• v) a mechanical device within said tank to partially obstruct the liquid flow in said conduit when said liquid reaches said imaginary plane so that further flow of said liquid through said tube is at a lower rate for the same pressure driving force, or requires a higher pressure driving force for the same flow rate;
• vi) at least one sensor located in said fluid conduit upstream of said inlet to generate a control signal when the pressure and liquid flow rate in said conduit correspond to the pressure and liquid flow rate created by said mechanical device when the liquid level in said tank reaches said imaginary plane;
• and
• vii) a fluid dispensing control means connected to said sensor, for stopping liquid flow through said conduit in response to said control signal.