Description of the operation method of the pneumatic valve Introduction to the working principle

Here are some of the well-known brands recognized in the valve industry, which are widely recognized and have a high reputation. While rankings may vary depending on time and market conditions, the following brands are generally considered to be among the top brands in the valve industry:

The following influential first-line brands of water system valves and industrial valves can be used as a reference, but for reference only: Suzhou Neway Valve, Shanghai Guanlong Valve, Shanghai Qizhong Valve, Sanhua, Chaoda, Shentong, Su Valve, Nanfang, Jiang.

First, the word Yao. The above manufacturers are only estimates and references, and the specific situation may vary or fluctuate at any time due to changes in a series of factors such as changes in the market, the size of the competition pattern, and the stability of product quality. As an indispensable key device in industrial production and civil facilities, the quality and reputation of the valve brand directly affect the satisfaction and trust of users.

Schematic diagram of the working principle of pneumatic valve:The pneumatic control valve consists of an actuator and a regulating mechanism. The actuator is the thrust part of the regulating valve, which generates the corresponding thrust according to the magnitude of the control signal pressure and pushes the regulating mechanism to act.

The valve body is the regulating part of the pneumatic control valve, which is in direct contact with the regulating medium and regulates the flow of the fluid.

Features:

No pressure loss, no blockage, no leakage, low gas consumption, waterproof hammer, etc., especially suitable for liquid-solid and gas-solid two-phase flow containing particles, can be widely used in particles, powder, fiber, clay and other abrasive substances in the chemical, pulp, paper, food, electric power, recycling, water treatment, mineral processing and other industries, rubber pipes are made of imported natural rubber with high elasticity, high wear resistance and fatigue resistance.

1. Pneumatic valves are divided into three types: single-acting, double-acting and intelligent adjustment. The piston structure in the single-acting pneumatic actuator is driven by a spring, and there are two principles: open and normally closed, either air open or air closed.

2. When there is no gas ingress, the piston is pushed by the spring to close the valve, which is normally closed. When the gas enters the cylinder, the valve is closed, and when the gas is cut off, it is opened by the spring piston valve, and the eating structure is open.

3. Double-acting is the principle of gas opening and gas closing, double-acting pneumatic valve needs to be equipped with two-position five-way solenoid valve, when the air hole A gas enters the cylinder to drive the piston to rotate the torque valve to close, when the valve is opened, the gas enters from the B air hole and the A mouth section is disconnected, and the piston drives the torque valve to open.

The working principle of the pneumatic control valve is: compressed gas as the power source, the cylinder as the actuator, and with the help of valve positioner, converter, solenoid valve, position retention valve, gas storage tank, gas filter and other accessories to drive the valve, to achieve switching or proportional adjustment, and receive the control signal of the industrial automation control system to complete the adjustment of the pipeline medium: flow, pressure, temperature, liquid level and other process parameters.

Pneumatic control valve is one of the industrial process control instruments widely used in petroleum, chemical, electric power, metallurgical and other industrial enterprises. It is usually formed by the combination instrument formed by the connection and installation and commissioning of pneumatic actuators and control valves. According to the valve action mode, it can be basically divided into:

There are two modes: straight stroke and angular stroke.

The working principle of pneumatic pressure regulator is to use compressed gas as the power source, the cylinder as the actuator, and with the help of valve positioners, converters, solenoid valves, position retention valves, gas storage tanks, gas filters and other accessories to drive the valve, to achieve switching or proportional adjustment.

The pneumatic control valve is a kind of quarter-angle rotary structure, which is used with the valve positioner to achieve proportional adjustment; The V-shaped spool is most suitable for various adjustment occasions, with large rated flow coefficient, large adjustable ratio, good sealing effect, sensitive adjustment performance, small size, and can be installed vertically. It is suitable for controlling gas, steam, liquid and other media.

The pneumatic piston actuator uses compressed air as the power source, and drives the crank arm to rotate 90 degrees through the movement of the piston to achieve automatic opening and closing of the valve. Its components are: adjusting bolts, actuator boxes, crank arms, cylinder blocks, cylinder shafts, pistons, connecting rods, cardan shafts.

<>When the user turns off the switch with the gas appliance closed, as the LPG enters the pressure reducing chamber increases, the rubber film pressed by the spring is pushed up, and part of the air existing in the upper air chamber is discharged from the valve body through the breathing hole. In this way, the lever is forced to move upward, and the valve port is closed by the lever, cutting off the passage to the LPG inlet, and the pressure at the outlet of the pressure reducing valve does not rise.

When the switch of the gas appliance is opened, the liquefied petroleum gas flows out from the pressure reducing valve, so that the pressure in the pressure reducing chamber drops, the rubber film is concave, driving the lever to move down, and the external air enters the upper air chamber from the breathing hole, so that the valve pad moves to the middle, the inlet nozzle becomes larger, the air intake of the reversal increases, and the pressure increases. This repeated adjustment process makes the pressure in the decompression chamber always constant, that is, no matter whether the inlet pressure is high or low, the outlet pressure is always stable, so as to reduce the pressure and stabilize the pressure. The pressure reducer, also known as the pressure reducer, is used to reduce the gaseous liquefied petroleum gas from the kilogram square centimeter in the cylinder to 250-350 mm water column pressure at a time, for the use of the burner, and the other role is to stabilize the pressure, no matter how the outlet pressure of the cylinder changes, the outlet low pressure after the pressure adjustment through the pressure regulator is stable, so as to ensure the normal combustion of the gas appliance.

Its working principle: open the cylinder angle cutting, the inlet pressure increases, the liquefied petroleum gas enters the decompression chamber increases, so that the decompression chamber rises, in this way, the film is convex, and part of the chamber gas in the upper air chamber is discharged from the breathing hole, so that the film drives the structure rod to move up, so that the cutting pad moves down close to the air nozzle, the air intake decreases, and the pressure decreases. When the pressure of the air reduction chamber drops to a certain extent, the film is concave, driving the lever to move downward, the upper air chamber becomes a negative pressure, and part of the external air is inhaled through the breathing hole, at this time, the cutting pad moves upward, the air intake nozzle becomes larger, the air intake volume also increases, and the pressure increases, which judges the reed sample from a connected air source, through several times such a film moves up and down, it can supply air normally with the required outlet working pressure, and when the air inlet pressure changes, the outlet pressure is also constant at a certain value through such an action, and plays the role of decompression and stability. Ensure that the gas appliance burns normally.

The pressure regulator is a valve that reduces the inlet pressure to a certain required outlet pressure by adjusting and relying on the energy of the medium itself to automatically maintain a stable outlet pressure. From the point of view of fluid mechanics, the pressure reducing valve is a throttling element whose local resistance can change, that is, by changing the throttling area, the flow rate and the kinetic energy of the fluid are changed, resulting in different pressure losses, so as to achieve the purpose of pressure reduction.

How the pressure reducing valve works:

The pressure reducing valve is to control the opening of the opening and closing parts in the valve body to adjust the flow of the medium, reduce the pressure of the medium, and at the same time adjust the opening of the opening and closing parts with the help of the pressure behind the valve, so that the pressure behind the valve is kept within a certain range, and spray cooling water in the valve body or behind the valve to reduce the temperature of the medium, this valve is called pressure reducing and hypothermic valve. The pressure reducing valve is fast and easy to optimize the automatic selection. The valve is characterized by keeping the outlet pressure and temperature values within a certain range when the inlet pressure is constantly changing.

According to the structural form, the pressure reducing valve can be divided into diaphragm type, spring diaphragm type, piston type, lever type and bellows type; According to the number of seats, it can be man-made single-seat and double-seater; According to the position of the disc, it can be divided into positive and negative type. When the output pressure of the pressure reducing valve is high or the diameter is large, the spring rate will be too large, and the output pressure will fluctuate greatly when the flow rate changes, and the structural size of the valve will also increase. To overcome these shortcomings, pilot-operated pressure reducing valves can be used.

The operating principle of a pilot-operated pressure reducing valve is basically the same as that of a direct-operated valve. The pressure regulating gas used in the pilot operated pressure reducing valve is supplied by a small direct-acting pressure reducing valve. If a small direct-acting pressure reducing valve is installed inside the valve body, it is called an internal pilot operated pressure reducing valve; If a small direct-acting pressure reducing valve is installed outside the main valve body, it is called an externally operated pressure reducing valve.

The pressure regulator can basically be said to be a pressure reducing valve, the working principle of the pressure reducing valve is as follows: the high-pressure medium is charged into a relatively large cavity through a small hole to achieve pressure reduction, in fact, it is by intercepting the flow and reducing the pressure, the two sides of the diaphragm or piston are out of the mouth, and the other side is the pressure given by artificially, and the valve stem that controls the size of the small hole is connected to the diaphragm (piston), so that as long as a fixed pressure is given, then the pressure out of the mouth will always be equal to this pressure, which is considered to be provided by a spring or an air source or a hydraulic source.

A pressure regulator can basically be said to be a pressure reducing valve.

Decompression principle: The high-pressure medium is charged into a relatively large cavity through a small hole to achieve decompression, which is actually decompressed by interception.

The diaphragm or piston is artificially applied pressure on one side of the mouth and the other side, and the stem that controls the size of the hole is connected to the diaphragm (piston).

In this way, as long as a fixed pressure is given, then the pressure out of the mouth will always be equal to this pressure, which is thought to be provided by a spring or an air or hydraulic source.