What is valve control?
According to the definition recorded in ISA-S75.05, CONTROL VALVE is a device that operates by applying a force other than manual force. The control valve or control valve regulates the amount of fluid flow in a process control system. The control valve consists of a valve that is connected to a drive mechanism, which has the ability to change the fluid control agent. This change that the hydraulic control valves make is based on the signal that these valves receive from the control system. A valve is a device used to control the flow and pressure of fluids.
Electric valve control: The valve control is a valve that acts by applying a force other than hand force and regulates the flow of fluid in a process control system. The control valve consists of a valve that has an actuator mechanism that has the ability to change the element. The fluid controller is connected. This change is based on the signal received from the control system.
Valve control components
The body of milk is the main part of milk that is under pressure. This section includes connections-
And is the flow path. This section also provides the necessary space for the seat and the seat and the plug.
The stem is the part of the lion in which the stem moves and serves as a guide for the stem. The valve stem also contains a sealing box. The stem can be monolithic, helical or flanged.
The actuator is one of the basic and important parts in control valves. Its job is to apply force and pressure to the valve stem and move it to change the position of the blocking member. The fluid flow is adjusted or disconnected and connected by moving the blocking member. There are different types of stimuli.
The part of the actuator that converts fluid or electrical or mechanical energy into the movement of a valve rod.
A device in which the energy of a compressible fluid usually converts air into motion.
A device that converts electrical energy into motion.
Determines the position of the valve, for example, open or closed position.
Each valve assumes a specific position, such as open or closed, by a moving part such as a spring. Each switched position is indicated by a square. The squares that are placed next to each other indicate the number of valve switch positions mentioned. For example, two squares means two switch positions. The direction of flow inside the squares are determined.
Standing or normal position
The position that the milk assumes before stimulation.
How to name a tap
The valve name depends on the number of switch positions and the number of openings of the valve. For example, 2/3 (three-two) starter valve means a valve that has 3 openings and two switch positions. When saying the name of the lion, the position of the lion’s position is also expressed. For example, a 3/4 valve with a normal closed position. Common types of starter valves are 3.5, 2.5, 3.4, 2.4, 2.3, 2.2.
The number on the right represents the number of valve states and the number on the left shows the number of valve ducts. When we say 2/2 valve, it means that this valve has 2 states and 2 ducts:
In all maps, the symbol of the lions is drawn in the stop mode, which is called “idle mode”.
In valve 2, the left square position is considered and in the middle 3 square position, it is considered as not working.
The appendix contains the symbol of a number of valves used in hydraulics.
Stimulation of milk
Valves are actuated by a variety of manual, electrical, mechanical, hydraulic and pneumatic mechanisms.
The main tasks of industrial valves
The main functions of industrial valves are as follows:
1) Complete disconnection and connection of current.
2) Prevents the return of liquids and gases that have passed.
3) Adjusts the amount needed to pass liquids and gases.
4) Adjusts and controls the amount and pressure of liquids and gases.
5) Controls pressure devices and makes them safe.
And basically hydraulic valves are used in places where there is a pressure difference for the flow of fluid (liquid and gas).
The function of hydraulic valves is to control the energy of the hydraulic fluid in a hydraulic circuit.
Classification of lions
Classification of valves in terms of type of performance
Directional control valve
Pressure control valve (pressure control)
Flow control valve (flow control)
Classification of valves in terms of type of stimulation
Fluid pressure (hydraulic-pneumatic)
The name is a cylindrical piece of metal that is placed inside the hydraulic valves and can move inside the valve. At certain distances from the length of the cylinder, certain parts are carefully cut and machined. As a result, the machined parts of the cylinder body, when placed inside the valve cylinder facing 2 or more ducts, allow the oil to pass, and the uncut parts of the cylinder also block the passage of oil. The low tolerance of these parts, any misalignment in the spool and its cylinder, causes malfunction and failure of the valve. Therefore, ring grooves are formed on the uncut parts of the cylindrical body, which create a hydraulic cushion or oil ring with oil penetration in them and keep the spool in the center of the cylinder.