Abstract: The invention described in the patent is an automatic control system which provides monitoring, supervision, and control of the process of filling of a tank or container with a liquid. The invention is applicable to cases where the liquid is handled in contact with its own vapor only, or where the liquid must be maintained at all times under a specified gas pressure. The invention provides an improved method of carrying out the process of filling of tanks or containers with liquids such as ammonia, chlorine, propane, liquefied petroleum gas, or with liquids such as carbonated beverages. The main advantage provided by the apparatus and method of the present invention is that an improved means is included for automatically stopping the filling process at the correct point, so as to avoid a possibly hazardous overfilled condition.

Abstract: The invention described in the patent is an automatic control system which provides monitoring, supervision, and control of the process of filling of a tank or container with a liquid, where at the temperature of operation the vapor pressure of the liquid is at or above atmospheric pressure. The invention provides an improved method of carrying out the process of filling of tanks with liquids such as ammonia, chlorine, propane, liquefied petroleum gas or any other liquid with high vapor pressure at the temperature of operation. The main advantage provided by the apparatus and method of the present invention is that an improved means is included for automatically stopping the filling process at the correct point, so as to avoid a possibly hazardous overfilled condition. One of the methods currently in use requires a mechanical valve which senses liquid level in the tank and is supposed to close so as to stop flow to the tank when the liquid has reached the maximum allowable level.

Abstract: The invention described in the patent comprises a method and an apparatus for automatically stopping the process of filling of a tank or container with a liquid, where the liquid must always be maintained under a gas or vapor pressure higher than atmospheric pressure. In the situations to which the invention is addressed, the tank is not to be filled completely with liquid. If the tank is correctly filled, there is at the end of the filling process a certain fraction of the total internal tank volume which is still occupied by gas or vapor. The invention provides for automatically stopping the fill at the correct point, through installation of one of several different devices within the tank, and through the operation of a microprocessor which receives signals from sensors located in the liquid supply system, upstream of the filling hose.