A computer-implemented method for operating a shut-off device for a fluid includes: using a mathematical model to calculate a current static fluid pressure at a location of interest within a shut-off device as a function of at least one measured state variable of the fluid; determining a vapor pressure of the fluid; comparing a current static fluid pressure with a cavitation limit value which is dependent on a vapor pressure of the fluid; and in the event of the calculated current static fluid pressure falling below the cavitation limit value dependent on the vapor pressure of the fluid, signaling the presence or expected presence of cavitation at the location of interest of the shut-off device. A related shut-off device is also disclosed.

A fluid distribution manifold may receive a first required flow rate for a first flow of fluid that flows to a fluid handling device or a reservoir. A first operation state may be determined for a first valve assembly that regulates the first flow, the manifold may operate the first valve assembly based on the first operation state, and a first position tracker may be incremented based on the first operation. Based on a value of a cycle tracker, the manifold may identify a second valve assembly in an operation cycle and access a second control input that includes a second required flow rate for a second flow of fluid regulated by the second valve assembly. The manifold may cause the second valve assembly to operate based on at least one of a second operation state and a change in the second actual flow rate resulting from the first operation.

A pressure transducer assembly is disclosed for directly monitoring pressure in a fluid which flows through the assembly. The pressure transducer can include a housing comprising a flow restrictor, an inlet port, and an outlet port. A poppet can be coupled with the housing. The flow restrictor can be defined by a valve seat of the housing between the inlet port and the outlet port.

A solenoid valve having a solenoid body with a solenoid receiving cavity and a flow receiving passage. A solenoid assembly is provided in the solenoid receiving cavity. A valve is provided in the flow receiving passage. An armature extends from the solenoid to the valve. The solenoid valve also includes a control circuitry, a power connection and a bidirectional communications connection. At least one sensor is provided in the flow receiving passage. The at least one sensor is in communication with the control circuitry. When in operation, power is continuously supplied through the power connection and the actuation of the solenoid valve is initiated by the bidirectional communications connection.

A metering valve comprising a solenoid having: a coil mounted on a core; and an armature moveable axially with respect to the core and against a return bias in response to a current in the coil; a variable capacitor having a first plate mounted for movement with the armature and a second plate fixed with respect to the core. The metering valve comprises an electronic feedback loop which is used to adjust the current in the coil based on a feedback signal derived from of the capacitance of the variable capacitor. A reference capacitor may be provided having opposing third and fourth plates at a set separation. A valve body may house the solenoid, the variable capacitor and the reference capacitor.

A mass flow control apparatus and methods for calibrating and tuning the mass flow apparatus are provided. The mass flow apparatus can be calibrated by receiving a calibration input signal that provides one or more properties of a gas that is flowing through a main fluid flow path and performing one or more measurements, using one or more sensors, on the gas. The calibration includes determining a calibration parameter based on the results of the one or more measurements and the calibration input signal and adjusting a proportional valve, based on the calibration parameter, to adjust a flow rate, of the gas through the apparatus, to match a setpoint flow rate.

In accordance with at least one aspect of this disclosure, a system can include, a moveable component configured to move between one or more positions, a biasing member operatively connected on a first side to bias the moveable component to a respective one of the one or more positions, and a preload member operatively connected to provide a force to a second side of the biasing member. An actuator can be operatively connected to move the preload member in response to a signal from a controller.

A fluid pressure proportional valve includes a valve body, a first core shaft, a second core shaft, and a driving motor. The valve body has a first orifice, a second orifice, a third orifice, and a receiving space having a valve port. The first and second core shafts are located in the receiving space. The first core shaft has a sealing portion, an abutting portion, and a flow channel. Under normal status, the sealing portion seals the valve port, and the second orifice communicates with the third orifice via the flow channel When the driving motor drives the second core shaft to move along an axial direction, the second core shaft could seal the flow channel to block the communication between the second orifice and the third orifice and push the abutting portion of the first core shaft to depart from the valve port and the sealing portion, thereby communicating the first and the second orifices.

A fluid control device includes a fluid resistance element provided to a channel, an upstream pressure sensor configured to detect an upstream pressure of the fluid resistance element, a downstream pressure sensor configured to detect a downstream pressure of the fluid resistance element, a flow rate calculating unit configured to calculate a flow rate flowing through the channel based on the upstream and downstream pressures, a valve provided upstream of the upstream pressure sensor or downstream of the downstream pressure sensor, and a valve control unit configured to control the valve based on the calculated flow rate. When the valve is fully closed, the flow rate calculating unit is configured to calculate the flow rate by switching a first flow rate calculation formula that is used when the valve is open, to a second flow rate calculation formula that is different from the first flow rate calculation formula.

A motor-driven axial-flow control valve is disclosed that has a valve body with an inlet and an opposite outlet and a passage located between having a substantially axial alignment relative to the inlet and outlet, and a flow control path arranged in the passage with an operative connection to a motor drive in a switch housing resting on the valve body. The flow control valve is formed by two radially arranged discs lying on one another and each having at least one passage opening where one disc is a stator disc permanently arranged in the valve body, and the other disc lies axially rotatably on the stator disk, and the rotatable disc is in engagement with an axially rotatable sleeve that is arranged axially in the passage and through which flow can pass in the cavity of the rotatable disc.