The working principle of the butterfly check valve

The <> double-flap structure features two spring-loaded discs (semi-valve) suspended from a central vertical chain pin shaft. When the fluid begins to flow, the disc opens with a resultant force acting on the center of the sealing surface.

The point of action of the counteractive spring support force is located outside the center of the disc face, so that the root of the disc opens first. This avoids the friction on the sealing surface that occurs when the disc is opened in older conventional valves, eliminating wear and tear on components.

When the flow rate slows down, the torsion spring automatically reacts, causing the disc to close and move closer to the body seat, reducing the travel distance and time of closing. When the fluid flows backwards, the disc gradually approaches the valve body seat, and the dynamic reaction of the valve is greatly accelerated, reducing the cumulative effect of water hammer and achieving impact-free performance. When closing, the action of the spring force action point causes the top of the disc to close first, preventing biting and friction at the root of the disc, so that the valve can maintain the integrity of the seal for a longer time.

During the use of this valve, the medium flows in the direction of the arrow shown in the figure.

1. When the medium flows in the specified direction, the valve disc is opened by the force of the medium; When the medium is reversed, the valve disc and the sealing surface of the valve seat are closed due to the action of the self-weight of the valve disc and the reverse force of the medium, so as to prevent the medium from flowing backwards.

2. The sealing surface of the valve body and disc is welded with stainless steel.

3. The structural length of this valve is in accordance with the provisions of GB12221-1989, and the flange connection size is in accordance with the provisions of JB T79-1994.

Material classification. Valve body: cast iron body, carbon steel body, stainless steel.

Disc l, aluminium bronze.

Seat: EPDM, nitrile.

Gasket: PTFE.

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, Su Yan, 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.

These brands are known in the valve industry for their innovative technology, high-quality products and reliability. It is important to note that the market and industry are evolving rapidly, and different rankings may vary depending on time and region. For the most up-to-date ranking information, it is recommended to refer to industry reports, professional organizations or market research data for more detailed and accurate information.

Butterfly valve principle: The butterfly valve rotates the valve stem by operating the transmission device, and at the same time, the valve stem drives the butterfly plate to rotate to achieve opening and closing. In the cylindrical channel of the valve body of the butterfly valve, the disc-shaped butterfly plate is connected with the valve stem, the valve stem rotation will drive the butterfly plate to rotate to do flow control, the rotation angle is between 0 degrees and 90 degrees, when the butterfly plate rotation reaches 90 degrees, the butterfly valve is in the fully open position in the pipeline, at this time, only the thickness of the butterfly plate is the only resistance for the fluid to pass, the flow resistance is very small, and when the butterfly plate rotation angle is between 0-90, it can be used to adjust the medium flow.

Check valve principle: check valve refers to the valve that automatically opens and closes the valve disc by relying on the flow of the medium itself, which is used to prevent the medium from flowing backwards, and the function of the check valve is to only allow the medium to flow in one direction, and prevent the flow in the opposite direction. Usually this kind of valve works automatically, and the disc opens under the action of fluid pressure flowing in one direction; When the fluid flows in the opposite direction, the fluid pressure and the self-closing disc of the disc act on the valve seat, thus cutting off the flow.

The disc valve directly cuts off the water, and the check valve refers to the valve where the water cannot flow back.

Crown valve pushing.

Butterfly valves are butterfly valves.

A check valve is a check valve.

Butterfly valves are mainly used for on-off purposes.

Check valves are mainly used to stop the backflow of water from pipelines.

Both can only be said to be valves.

Everything else is different.

The working characteristics of the check valve are that the load changes greatly, the opening and closing frequency is small, and the application cycle is very long as it is put into the closed or open state, and it does not require the movement of moving parts. However, once there is a "switching" requirement, it must be moved flexibly, which is more demanding than the usual mechanical movements. Since the check valve is qualitatively determined to be used for rapid closing in most practical uses, and at the moment when the check valve is closed, the medium flows in the direction of the disc, and with the closure of the valve disc, the medium rapidly decreases from the maximum reverse flow speed to zero, while the pressure rises rapidly, that is, the "water hammer" phenomenon that may have a destructive effect on the pipeline system is generated.

For high-pressure piping systems where multiple pumps are connected in parallel, the problem of water hammer on check valves is even more prominent. Water hammer is a kind of pressure wave in the transient flow in the pressure pipeline, which is the hydraulic shock phenomenon caused by the change of the fluid flow rate in the pressure pipeline. The physical cause is the combined effect of the incompressibility of the fluid, the inertia of the fluid motion and the elasticity of the pipeline.

In order to prevent the hidden danger of water hammer in the pipeline, over the years, people have adopted some new structures and new materials in the design of the check valve, and gratifying progress has been made in reducing the impact force of the water hammer to a minimum while ensuring the applicable performance of the check valve. Check valve refers to the valve that automatically opens and closes the valve disc by relying on the flow of the medium itself to prevent the medium from backflowing, also known as check valve, check valve, reverse flow valve, and back pressure valve. The check valve is an automatic valve, and its main function is to prevent the backflow of the medium, prevent the pump and the drive motor from reversing, and the discharge of the container medium.

Check valves can also be used on lines that supply auxiliary systems where pressure may rise above the system pressure. Check valves can be mainly divided into swing-type check valves (rotating according to the center of gravity) and lifting check valves (moving along the axis).

The role of check valves, safety valves, and butterfly valves.

1.Check valve can prevent the backflow of medium Check valve has only one flow direction, which flows in the direction of the water inlet to prevent water from flowing backwards. The flow medium flows in from the inlet (bottom) and out from the outlet (top).

The valve is opened when the inlet pressure is greater than the sum of the disc weight and its trapped burial resistance. Conversely, the check valve is closed when the medium flows backwards. 2.

The check valve prevents the pump and drive motor from reversing Since the check valve works automatically, the disc opens at the pressure of flow in only one direction. When the liquid flows in the opposite direction, the self-closing disc with the fluid pressure and the width of the disc acts on the valve seat, thus cutting off the flow. 3.

Increasing Pressure Check valves are used to increase the pressure applied to the line beyond the pressure provided by the system pressure assist system to prevent accidents. 2. What should be paid attention to in the installation of check valve 1. In order to avoid the backflow of the medium in the pipeline, it is necessary to install the check valve whether it is equipment or pipeline. 2. Check valves are mostly used for cleaning.

Summary. Gate Valve: Features:

The valve that uses the ram to lift and control the opening and closing, the flow direction of the fluid does not change when it passes, so the water flow resistance is small and the tightness is poor. Application: It should not be used on pipelines that need to be adjusted in size and opened and closed frequently.

Widely used in hot and cold water piping systems; It is mainly used in some large-diameter pipes. Butterfly Valve: Features:

The structure and operation are simple, fast opening and closing, and have good fluid control characteristics. Application: Suitable for installation on large diameter pipes.

Check Valve: Feature: One-way, suitable for cleaning media, not suitable for media with solid particles and viscosity.

Application: Lifting check valve can only be used for horizontal pipes, swing check valve for vertical and horizontal pipes.

The role of check valves, safety valves, and butterfly valves.

Gate valve: Features: The valve that uses the gate to lift and control the opening and closing, the flow direction remains unchanged when the fluid passes, so the water flow resistance is small and the tightness is poor.

Application: It is not suitable for the need to adjust the size and frequent opening and closing of the pipeline. Widely used in hot and cold water piping systems; It is mainly used in some large-diameter pipes.

Butterfly valve: Features: simple structure and operation, fast opening and closing, with good fluid control characteristics.

Application: Suitable for installation on large diameter pipes. Check Valve:

Features: unidirectional, suitable for cleaning media, not suitable for media with solid particles and viscous chirality. Applications:

Lift-type check valves can only be used for horizontal pipes, and swing-type check valves are used for vertical and horizontal pipes.

Gate valve: Features: The valve that uses the gate to lift and control the opening and closing, the flow direction remains unchanged when the fluid passes, so the water flow resistance is small and the tightness is poor.

Application: It should not be used on pipelines that need to be adjusted in size and opened and closed frequently. Widely used in hot and cold water piping systems; It is mainly used in some large-diameter pipes.

Butterfly Valve: This Tanlu features: simple structure and operation, fast opening and closing, with good fluid control characteristics.

Application: Suitable for installation on large diameter pipes. Check Valve:

Features: unidirectional, suitable for cleaning media, not suitable for media with solid particles and viscosity. Applications:

Shengsen with descending check valve can only be used for horizontal pipes, and swing check valves are used for vertical and horizontal pipes.

For the check valve with the butterfly check disc rolling along the vertical axis of the valve body, the threaded check valve can only be installed in the horizontal pipeline, and the piston valve can be taken as a ball on the high-pressure caliber check valve. The body of the stacked check valve is the same as that of the shut-off valve (it can be used in conjunction with the shut-off valve), so its fluid resistance coefficient is relatively large. The structure is similar to that of the globe valve, and the body and piston valves are the same as the globe valves.

The upper end of the piston valve and the lower edge of the single-flow valve are produced and processed with a rough mountain sleeve, the piston valve can be adjusted at will from the valve lamp guide, when the medium is downstream, the piston valve is opened by the medium push, and when the medium stops flowing, the piston valve falls on the valve seat by self-sagging, which prevents the medium from flowing backwards.