Provided are a control method, a control system and an electric valve. The control method includes steps described below. An actually measured setting parameter curve is acquired. A required setting parameter curve is acquired. Both the actually measured setting parameter curve and the required setting parameter curve represent a corresponding relationship between a position of the electric valve and a setting parameter. The actually measured setting parameter curve and the required setting parameter curve are fitted to acquire a position mapping curve. A setting required position is obtained according to a required setting parameter and the required setting parameter curve, and a setting actual position is acquired according to the setting required position and the position mapping curve. The electric valve is controlled to run toward the setting actual position of the electric valve.

Provided are a control method, a control system and an electric valve. The control method includes steps described below. An actually measured setting parameter curve is acquired. A required setting parameter curve is acquired. Both the actually measured setting parameter curve and the required setting parameter curve represent a corresponding relationship between a position of the electric valve and a setting parameter. The actually measured setting parameter curve and the required setting parameter curve are fitted to acquire a position mapping curve. A setting required position is obtained according to a required setting parameter and the required setting parameter curve, and a setting actual position is acquired according to the setting required position and the position mapping curve. The electric valve is controlled to run toward the setting actual position of the electric valve.

The invention relates to a pressure maintaining gas cylinder valve. It consists of a pressure retaining device: The axis of the pressure retaining device and that of the valve element are in the same vertical plane; the pressure retaining device has a mounting base, a spring and a valve are located in the mounting base: the valve is in the valve element near the air outlet; the front section of the valve is near the air outlet, while the rear section of the valve is in the mounting base; the spring is between the valve and the mounting base. Because the invention has no eccentricity, the gas channel is smoother and the volume of the cylinder valve is greatly reduced. The mounting seat of the pressure retaining device not only provides support for the valve and spring, but also ensures that the stroke of the valve element is not interfered.

A flow rate adjustment valve includes: a flow path portion which has one end at which an opening is formed, and in which a fluid flows; a lifting valve which is configured to close the opening by covering an entire region of the opening, open the opening by being separated from the opening in an opening direction of the opening, and change a distance from the opening in the opening direction to change a flow area with respect to the opening; and a servo actuator as a driver which moves the lifting valve in the opening direction based on a predetermined detection value.

A valve for applying an emergency brake of a rail vehicle includes a valve housing, an actuation member to be activated by a user, an actuation rod connecting the actuation member with a valve head, wherein the valve head is adapted to abut on a valve seat, a guidance for guiding the actuation rod being provided within the valve housing, and a first spring adapted to push the valve head against the valve seat, wherein the actuation rod includes a first groove and a second groove, and wherein a first following member is provided between the actuation rod and the guidance, being adapted to stably rest in the first groove or the second groove.

An apparatus, system and method for regulating fluid flow are disclosed. The apparatus includes a flow rate sensor and a valve. The flow rate sensor uses images to estimate flow through a drip chamber and then controls the valve based on the estimated flow rate. The valve comprises a rigid housing disposed around the tube in which fluid flow is being controlled. Increasing the pressure in the housing controls the size of the lumen within the tube by deforming the tube, therefore controlling flow through the tube.

An apparatus, system and method for regulating fluid flow are disclosed. The apparatus includes a flow rate sensor and a valve. The flow rate sensor uses images to estimate flow through a drip chamber and then controls the valve based on the estimated flow rate. The valve comprises a rigid housing disposed around the tube in which fluid flow is being controlled. Increasing the pressure in the housing controls the size of the lumen within the tube by deforming the tube, therefore controlling flow through the tube.

In order to provide a piezo valve in which it is possible to accurately predict the remaining lifespan of a piezo actuator, there are provided a valve seat, a valve body that is able to move between a fully closed position in contact with the valve seat and a fully open position, a piezo actuator that drives the valve body, a drive circuit that receives an input signal, and outputs to the piezo actuator a corresponding drive voltage, and a leakage current detector that, when the drive circuit outputs a voltage equal to or greater than a maximum rated voltage that drives the valve body to the fully closed/open position, detects leakage current from the piezo actuator. When the leakage current is detected or in a state immediately prior to detection, a fluid is flowing between the valve seat and the valve body.

A fluid micro-injection device comprises an execution system (100) and a flow channel assembly (200) connected with the execution system (100). The execution system (100) includes a base body (110), a movable member (120), an executor, an adjusting member (130) and a plurality of clearance sheets. The flow channel assembly (200) have a fluid seat (210), a nozzle (220) and a fluid supply joint (230).