Abstract: System, method, and apparatus for controlling circulation of fluid to, and evacuation of the fluid from, an external fluid circuit for heat transfer. A single control valve selectively stops the circulation of fluid from a supply passageway to an external fluid circuit and diverts fluid to a bypass passageway which creates a suction force at a venturi valve region therein. The venturi valve region includes a fluid jacket that encases at least a portion of the venturi valve region. A suction passageway couples the suction force of bypass passageway to either return passageway or supply passageway, for evacuating fluid from external fluid circuit. No more than a single suction passageway is required to be coupled to either supply passageway and/or return passageway. A return check valve disposed in return passageway prevents backflow of fluid through return passageway.

Abstract: System, method, and apparatus for controlling circulation of fluid to, and evacuation of the fluid from, an external fluid circuit for heat transfer. A single control valve selectively stops the circulation of fluid from a supply passageway to an external fluid circuit, and diverts fluid to a bypass passageway which creates a suction force at a fluid restriction therein. A suction passageway couples the suction force of bypass passageway to either return passageway or supply passageway, for evacuating fluid from external fluid circuit. No other valve is disposed or required in the supply passageway or the bypass passageway apart from the single control valve. No more than a single actuator is required to operate the apparatus. No more than a single suction passageway is required to be coupled to either supply passageway and/or return passageway. A return check valve disposed in return passageway prevents backflow of fluid through return passageway.

Abstract: System, method, and apparatus for controlling circulation of fluid to, and evacuation of the fluid from, an external fluid circuit for heat transfer. A single control valve selectively stops the circulation of fluid from a supply passageway to an external fluid circuit, and diverts fluid to a bypass passageway which creates a suction force at a fluid restriction therein. A suction passageway couples the suction force of bypass passageway to either return passageway or supply passageway, for evacuating fluid from external fluid circuit. No other valve is disposed or required in the supply passageway or the bypass passageway apart from the single control valve. No more than a single actuator is required to operate the apparatus. No more than a single suction passageway is required to be coupled to either supply passageway and/or return passageway. A return check valve disposed in return passageway prevents backflow of fluid through return passageway.

Abstract: A distributed digital control system includes a plurality of control modules which are interconnected by a communication link. Each module includes a processor unit for running a control program, and a plurality of system databases which correspond to nodes in the system. Each module further includes a selector such as a Dual Inline Package (DIP) switch for inputting a node number. The program automatically selects the database corresponding to the input node number when the module is powered up. The system preferably utilizes the industry standard LonTalk® protocol, with each database including Standard Network Variable Types (SNVTs) and Standard Configuration Parameter Types (SCPTs) for the respective node. A default database is also stored in each module, which is automatically used by the program if the system databases are not found.

Abstract: An apparatus detects an opening in a fluid flow passageway such as occurs when a resistance welding cap which is cooled by the fluid flow becomes accidently detached from a welding machine. Upon detection of an opening, an air-actuated pinch lever is activated to quickly pinch shut flexible fluid inlet and outlet hoses and thereby shut off the fluid flow. Inlet and outlet flow rate sensors provide periodic outputs to a digital computer which determines directions of inlet and outlet flow acceleration. If either the inlet or outlet acceleration changes direction, a baseline inlet or outlet flow rate is set equal to the corresponding current flow rate value to prevent erroneous opening detection due to normal flow fluctuations. If the inlet and outlet accelerations are in the same direction, the baseline values are similarly updated. If the inlet acceleration is positive and the outlet acceleration is negative, it indicates a probable opening.

Abstract: An apparatus detects an opening in a fluid flow passageway such as occurs when a resistance welding cap which is cooled by the fluid flow becomes accidently detached from a welding machine. Upon detection of an opening, an air-actuated pinch lever is activated to quickly pinch shut flexible fluid inlet and outlet hoses and thereby shut off the fluid flow. Inlet and outlet flow rate sensors provide periodic outputs to a digital computer which determines directions of inlet and outlet flow acceleration. If either the inlet or outlet acceleration changes direction, a baseline inlet or outlet flow rate is set equal to the corresponding current flow rate value to prevent erroneous opening detection due to normal flow fluctuations. If the inlet and outlet accelerations are in the same direction, the baseline values are similarly updated. If the inlet acceleration is positive and the outlet acceleration is negative, it indicates a probable opening.