Liquid level control system

A liquid level control system for use with a liquid reservoir having an inlet and having an outlet located at a predetermined liquid maintenance level in said reservoir, comprising:

• fluid amplifier means positioned relative to said reservoir for sensing an interface between liquid and gas, said fluid amplifier means developing a fluid pressure signal when said interface falls below said predetermined level;
• means in communication with said fluid amplifier means for circulating liquid between said outlet and said inlet, said circulation means including a circulation conduit for carrying said liquid from said outlet to said inlet, and means operatively associated with said circulation conduit for circulating said liquid;
• means for restricting flow of said liquid in said circulation conduit at said inlet, said flow restriction means including a restrictive orifice through which said liquid passes from said circulation conduit into said reservoir;
• a first tube connected to said fluid amplifier means communicates with said liquid in said circulation conduit adjacent said flow restriction means;
• fluid valve means responsive to said fluid pressure signal developed by said fluid amplifier means, said fluid valve means being normally closed in an inoperative position in the absence of said fluid pressure signal and opening in the presence of said fluid pressure signal;
• a second tube connected to said fluid amplifier means through which said fluid pressure signal is transmitted from said fluid amplifier means to said fluid valve means;
• and
• liquid supply means for adding liquid to said reservoir from an external liquid supply, said liquid supply means including a supply conduit for carrying said liquid to be added from said external liquid supply to said reservoir, said fluid valve means being disposed within said supply conduit.

A liquid level control kit for use with a liquid reservoir having an inlet and an outlet including a pipe for circulating liquid between said outlet and said inlet, comprising:

• a fluid amplifier positioned relative to said reservoir for developing a fluid pressure signal when an interface between liquid and gas falls below a predetermined level;
• a fluid valve responsive to said fluid pressure signal developed by said fluid amplifier for opening in the presence of said signal and closing in the absence of said signal;
• a cap capable of being secured to said pipe at said inlet, said cap having a restrictive orifice extending therethrough and also including first and second taps extending therethrough;
• a first tube capable of joining said fluid amplifier to said first tap in said cap for communication of said fluid amplifier with said circulating liquid in said pipe to develop said fluid pressure signal;
• and
• a second tube capable of joining said fluid amplifier to said fluid valve by passing through said second tap and said pipe for transmitting said fluid pressure signal to said fluid valve;
• whereby said fluid valve may be disposed within a supply line leading from an external liquid supply to said reservoir and said supply line may thereafter be automatically controlled by said fluid valve to maintain a predetermined liquid level within said reservoir.