A water valve, in which a water film is formed when the water valve connected to a water tank provided at a refrigerator door is opened and then closed and thus water film sealing is established downstream of an opening/closing surface of the water valve, thereby preventing dripping of water remaining in the water valve, enabling a clean use, and a refrigerator using the water valve. A valve body structure, in which a tube for guiding a flow of water toward a portion where a water film is to be formed between a nozzle and a valve is provided at the valve and an opening for releasing a water pressure even when the flow of water excessively concentrates, and thus, the water flowing through the opening may join a mainstream of the water discharged through a water passing hole.

A drippage prevention system including: a first automatic control valve (ACV), an input of the first ACV fluidically connected to a source of fluid to be dispensed, the first ACV having a position ranging from fully closed to fully open; a second ACV, an input of the second ACV being fluidically connected to the output of the first ACV, and an output of the second ACV being fluidically connected to a nozzle, the second ACV having positions ranging from fully closed to fully open; a proxy sensor configured to generate a proxy signal representing an indirect measure of a position of the first ACV; and a controller electrically connected to the first and second ACVs and the proxy sensor, the controller being configured to cause the second ACV to close based on the proxy signal and thereby stop flow of the liquid to the nozzle.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A first electrode coolant path is configured to cool a first welding electrode by liquid coolant flowing from a supply path through the first electrode coolant path to a return path. A second electrode coolant path is configured to cool a second welding electrode by liquid coolant flowing from the supply path through the second electrode coolant path to the return path. Three or more valves are configured to stop or reduce liquid coolant flow through the first or second electrode coolant path and configured to stop or reduce liquid coolant backflow from the return path when the first or second welding electrode is at least partially detached. At least one valve is coupled in the first or second electrode coolant path. A drawback apparatus generates a suction force to draw liquid coolant away from a gap formed when the first or second welding electrode is at least partially detached.

A suck-back valve includes a valve main body formed with a suck-back chamber, and a suck-back mechanism unit. The suck-back mechanism unit includes a suck-back piston accommodated in a suck-back cylinder chamber and being slidable between two dead center positions, and a biasing member biasing the suck-back piston in a direction to increase the volume of the suck-back chamber. The suck-back cylinder chamber is divided by the suck-back piston into a first fluid chamber and a second fluid chamber. The biasing member is arranged in the first fluid chamber, and a standby position at which the suck-back piston is positioned when the pressure of a drive fluid in the second fluid chamber becomes the maximum is set to be away from the dead center position on the side closer to the suck-back chamber.

A suck-back valve includes a valve main body formed with a suck-back chamber, and a suck-back mechanism unit. The suck-back mechanism unit includes a suck-back piston accommodated in a suck-back cylinder chamber and being slidable between two dead center positions, and a biasing member biasing the suck-back piston in a direction to increase the volume of the suck-back chamber. The suck-back cylinder chamber is divided by the suck-back piston into a first fluid chamber and a second fluid chamber. The biasing member is arranged in the first fluid chamber, and a standby position at which the suck-back piston is positioned when the pressure of a drive fluid in the second fluid chamber becomes the maximum is set to be away from the dead center position on the side closer to the suck-back chamber.

A method of preventing drippage in a liquid dispensing system includes generating at least a first proxy signal representing at least a first indirect measure of a position of a first automatic control valve (ACV), wherein the first ACV has positions ranging from fully closed to fully open. The method further includes recognizing, based on at least the first proxy signal, whether a failure state exists in which the first ACV has failed to close. The method further includes causing a second ACV to close when the failure state exists, wherein the second ACV is fluidically connected to the first ACV, and the second ACV has positions ranging from fully closed to fully open.

A method of preventing drippage in a liquid dispensing system includes generating at least a first proxy signal representing at least a first indirect measure of a position of a first automatic control valve (ACV), wherein the first ACV has positions ranging from fully closed to fully open. The method further includes recognizing, based on at least the first proxy signal, whether a failure state exists in which the first ACV has failed to close. The method further includes causing a second ACV to close when the failure state exists, wherein the second ACV is fluidically connected to the first ACV, and the second ACV has positions ranging from fully closed to fully open.