Ad
related to: modulating control valve operation manual free printable pdf
Search results
Results From The WOW.Com Content Network
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.
Modulating control valves each with 4-20mA I to P converter linked to pneumatic a valve positioner controlling a diaphragm actuator. An air-operated valve, also known as a pneumatic valve, is a type of power-operated pipe valve that uses air pressure to perform a function similar to a solenoid.
Manual actuators are powered by hand. Manual actuators are inexpensive, typically self-contained, and easy to operate by humans. However, some large valves are impossible to operate manually and some valves may be located in remote, toxic, or hostile environments that prevent manual operations in some conditions.
An isolation valve is a valve in a fluid handling system that stops the flow of process media to a given location, usually for maintenance or safety purposes. [1] They can also be used to provide flow logic (selecting one flow path versus another), and to connect external equipment to a system. [2]
All mass flow controllers have an inlet port, an outlet port, a mass flow sensor and a proportional control valve. The MFC is fitted with a closed loop control system which is given an input signal by the operator (or an external circuit/computer) that it compares to the value from the mass flow sensor and adjusts the proportional valve ...
Proportional control overcomes this by modulating the output to the controlling device, such as a control valve at a level which avoids instability, but applies correction as fast as practicable by applying the optimum quantity of proportional gain.
For continuously modulated control, a feedback controller is used to automatically control a process or operation. The control system compares the value or status of the process variable (PV) being controlled with the desired value or setpoint (SP), and applies the difference as a control signal to bring the process variable output of the plant ...
Pneumatically-actuated globe valves and diaphragm valves are widely used for control purposes in many industries, although quarter-turn types such as (modified) ball and butterfly valves are also used. Control valves can also work with hydraulic actuators (also known as hydraulic pilots). These types of valves are also known as automatic ...