Flood level sensor for fluid filling systems

In a flood preventer mechanism for controlling the level of fluid in a receptacle with an enclosed rim, the flood preventer mechanism including a vacuum line through which a partial vacuum is relieved to prevent actuation of a valve lockout device, an improvement comprising:

• an upstanding tube extending outside and above the receptacle, the tube having an upper end and the tube having a lower end that communicates with the enclosed rim of the receptacle;
• means at the upper end of the tube for locating a lower end of the vacuum line within the tube at a height related to a limit on the level of fluid in the receptacle;
• wherein an orifice is formed at the lower end of the vacuum line;
• and
• wherein the upstanding tube forms a vent to the atmosphere above the orifice, the vent being in communication with the orifice outside the vacuum line and inside the tube to maintain atmospheric pressure in a gap between the orifice and fluid entering the tube from the receptacle.

In a flood preventer mechanism for controlling the level of fluid in a receptacle having an enclosed rim, wherein the flood preventer mechanism includes a vacuum line to permit or inhibit relief of a partial vacuum drawn therethrough, an improvement comprising:

• an upstanding tube positioned outside the receptacle and coupled for fluid communication with the enclosed rim of the receptacle;
• means in the upper portion of the tube for locating a lower end of the vacuum line within the tube above the normal level of fluid in the receptacle and at a height related to a limit on the level of fluid in the receptacle;
• an orifice at the lower end of the vacuum line;
• and
• wherein the tube is vented to the atmosphere above the orifice to maintain atmospheric pressure on fluid entering the tube as the partial vacuum is drawn through the vacuum line.