A vacuum valve for driving a valve body arranged facing a valve opening up and down relative to the valve opening to perform valve opening/closing operation, comprises: a first up-down driver configured to drive the valve body up and down with a first minimum drivable amount; and a second up-down driver configured to drive the valve body up and down with a second minimum drivable amount smaller than the first minimum drivable amount.

Methods for managing a hazardous fluid within a pipeline and within a storage facility, and in particular for managing a potential or actual leak of the hazardous fluid. Such methods include the detection of such an event by one or more sensors, and the containment and the mitigation of the event.

An electronic flowmeter includes a body defining an interior, an inlet port in communication with the interior, an outlet port in communication with the interior, and a valve selectively adjustable between open and closed positions for communication between the outlet port and the interior. A flow sensor is associated with the valve and sensing a flowrate therethrough, and a digital indicator displays the flowrate sensed by the flow sensor.

Systems and methods is described herein for detecting a water leak. In an example, a method for detecting a water leak can include receiving at a water monitoring system (WMS) one or more radio-frequency (RF) signals, converting the one or more RF signals to a direct-current (DC) voltage, storing the DC voltage at a storage element, configuring the WMS to monitor a water source for water, generating a control valve signal in response to detecting the water, and providing the control valve signal to a shutoff valve to cause the shutoff valve to cut-off the flow of the water to the water source.

A non-invasive thermal dispersion flow meter with chronometric monitor for fluid leak detection includes a heater, an ambient temperature sensor and a flow rate sensor which are configured to sense the temperature of a fluid in a conduit, and then monitor the flow of that fluid through the conduit. The fluid flow sensor is incorporated into a

Wheatstone bridge circuit which is used to provide increased sensitivity to the outputs of the sensors. Based upon the ambient temperature sensor readings, the flow rate sensor and heater may be adjusted to optimize the operation of the system to detect leaks. An alternative embodiment utilizes a single sensor and separate heater which work together to determine heat propagation times which in turn is used to calculate flow rate.

Wet fire protection systems and methods for the protection of a stored commodity are provided. The system includes a supply portion coupled to a water supply and a demand portion including a plurality of sprinklers disposed above the commodity with each sprinkler having an operating pressure range. The plurality of sprinklers are interconnected by a network of pipes filled with water to provide each sprinkler with an initial pressure of water. A pressure control assembly is disposed between the supply portion and the demand portion to withhold fluid pressure from the supply portion from pressurizing the demand portion for a predetermined withholding period following actuation of at least one sprinkler in response to a fire.

The flow controller according to the present invention includes: a control valve; a first flow passage provided on the downstream side of the control valve; a second flow passage; and an expansion chamber provided between the first flow passage and the second flow passage. The second flow passage is provided in a position that is not on the extension of the first flow passage.

An electromagnetic valve as a fluid device is provided with a valve seat and a valve body midway of a flow path where a liquid flows, and closes the valve with the valve body pressed onto the valve seat and opens the valve by causing a gap between the valve seat and the valve body. The electromagnetic valve includes, as electrodes for measuring a degree of electrical conductivity between a liquid on an upstream side and a liquid on a downstream side of the valve seat and the valve body in the flow path, a first electrode electrically conductive to the liquid on the upstream side and a second electrode electrically conductive to the liquid on the downstream side. By using the first and second electrodes, detection of liquid leakage can be easily performed.

Provided are: a shut-off valve control device which is capable of reducing the difference between a set opening amount and the actual opening amount, when executing a partial valve stroke test; a shut-off valve control system; a method for calculating a shut-off valve control coefficient; and a method for controlling a shut-off valve. This shut-off valve control device is provided with a microcomputer for controlling the opening and closing of a solenoid valve which supplies air from an air supply source, to a cylinder of an air cylinder for controlling a valve shaft of a shut-off valve, and discharges said air. The microcomputer acquires a set opening amount of the shut-off valve. Furthermore, the microcomputer controls the solenoid valve to a value obtained by dividing the acquired set opening amount by a predetermined coefficient C.

A drive circuit is provided for controlling a solenoid valve having a solenoid coil. The drive circuit includes a first semiconductor device, a flyback circuit, and a processor. The first semiconductor is coupled in series with the coil and is controlled by a gate signal to energize the coil. The flyback circuit is in parallel with the coil and includes a series-coupled second semiconductor device and a diode. The second semiconductor is controlled by a flyback control signal to enable the flyback circuit when the first semiconductor is controlled by the gate signal to hold the valve open. The diode has a low forward voltage to slow decay of a current conducted through the coil. The processor generates the gate signal to control the first semiconductor and to reduce a duty cycle of the gate signal when the flyback circuit is enabled to reduce power consumption by the coil.