Search results
Results From The WOW.Com Content Network
The ASME B16 Standardization of Valves Flanges, Fittings and Gaskets Committee, which operates under ASME’s Board on Pressure Technology Codes and Standards is responsible for standards covering valves, flanges, pipe fittings, gaskets and valve actuators for use in pressure services.
And like a diode, too much reverse bias can damage or destroy the valve assembly. A transistor is a valve in which a diaphragm, controlled by a low-current signal (either constant current for a BJT or constant pressure for a FET), moves a plunger which affects the current through another section of pipe. CMOS is a combination of two MOSFET ...
The basic principle behind partial stroke testing is that the valve is moved to a predetermined position in order to determine the performance of the shut down valve. This led to the adaptation of pneumatic positioners used on flow control valve for use in partial stroke testing.
A rotary valve (also called rotary-motion valve) is a type of valve in which the rotation of a passage or passages in a transverse plug regulates the flow of liquid or gas through the attached pipes. [1] The common stopcock is the simplest form of rotary valve. Rotary valves have been applied in numerous applications, including:
A control valve is a valve used to control fluid flow by varying the size of the flow passage as directed by a signal from a controller. [1] This enables the direct control of flow rate and the consequential control of process quantities such as pressure, temperature, and liquid level.
The blue valve body is visible in-line with the pipe. The valve actuator opens or closes the butterfly disc of the valve based on electrical signals sent to the actuator. Another valve actuator is visible in the background, with windows to indicate the valve position. A valve actuator is the mechanism for opening and closing a valve. Manually ...
If the fluid is a liquid, a different type of limiting condition (also known as choked flow) occurs when the venturi effect acting on the liquid flow through the restriction causes a decrease of the liquid pressure beyond the restriction to below that of the liquid's vapor pressure at the prevailing liquid temperature.
This design results in significant increases in servo valve flow capability, stability, and force output. Similarly, three-stage servo valves may use an intermediate stage spool valve to position a larger third stage spool valve. Three-stage servo valves are limited to very high power applications, where significant flows are required.