How to choose globe valves, ball valves, butterfly valves, and gate valves

Gate valve: It is mainly used as a cut-off medium on the pipeline, which is fully open or fully closed, and generally cannot be used as a flow regulation. Butterfly Valve:

A butterfly valve is a type of valve that opens, closes, and regulates fluid pathways. Ball valve: It is mainly used on the pipeline to cut off, distribute and change the direction of the flow of the medium.

Globe valve: refers to the valve in which the shut-off (disc) moves along the centerline of the valve seat. The relatively short stem opening or closing stroke of this type of valve makes it ideal for regulating the flow rate.

Here are some 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.

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.

The globe valve is a forced seal valve, so when the valve is closed, pressure must be applied to the disc to force the sealing surface not to leak. When the medium enters the valve six from the bottom of the valve disc, the resistance that the operating force needs to overcome is the friction force of the valve stem and the packing material and the thrust generated by the pressure of the medium, and the force of closing the valve is greater than the force of opening the valve, so the diameter of the valve stem should be larger, otherwise the fault of the top bend of the valve stem will occur. In recent years, after the emergence of the self-sealing valve, the medium flow direction of the globe valve has been changed from the top of the disc to enter the valve cavity, at this time, under the action of medium pressure, the force of closing the valve is small, and the force of opening the valve is large, and the diameter of the valve stem can be reduced accordingly.

At the same time, under the action of the medium, this form of valve is also tighter. China's valve "three to give.""It has been stipulated that the flow direction of the shut-off valve shall be top-down.

When the globe valve is opened, the opening height of the disc is 25% of the nominal diameter 30%, the flow rate has reached the maximum, indicating that the valve has reached the fully open position. Therefore, the fully open position of the globe valve should be determined by the stroke of the disc.

The main characteristics of the ball valve are its compact structure, reliable sealing, simple structure, convenient maintenance, the sealing surface and the spherical surface are often in a closed state, not easy to be eroded by the medium, easy to operate and maintain, suitable for water, solvent, acid and natural gas and other general working media, but also suitable for the medium with harsh working conditions, such as oxygen, hydrogen peroxide, methane and ethylene, etc., which are widely used in various industries. The ball valve body can be monolithic or combined.

Ball valves and globe valves.

Difference 1: How it works.

The closing principle of the globe valve is to rely on the pressure of the valve stem to make the sealing surface of the disc and the sealing surface of the valve seat fit tightly to prevent the flow of medium. China's valve "three to give" has stipulated that the flow direction of the globe valve is all top-down, so there is directionality when installing. The structure length of the globe valve is greater than that of the gate valve, and the fluid resistance is large, and the sealing reliability is not strong during long-term operation.

The ball body of the ball valve is fixed and does not move when pressurized. Fixed ball valves are equipped with floating seats, and after being pressured by the medium, the valve seats move to make the sealing ring press against the ball to ensure sealing. Bearings are usually installed on the upper and lower shafts with the ball, and the operating torque is small, which is suitable for high-pressure and large-diameter valves.

Difference 2: Application field.

The national standard globe valve is a commonly used product in the globe valve series, the API American standard globe valve implements ANSI and API standards, and the sealing surface of the disc and valve seat is made of Stellite cobalt-based cemented carbide with different hardness, which has reliable sealing, high hardness, wear resistance, high temperature resistance, corrosion resistance, good scratch resistance and long life.

In China, ball valves are widely used in petroleum refining, long-distance pipelines, chemicals, papermaking, pharmaceuticals, water conservancy, electric power, municipal, steel and other industries, and occupy a pivotal position in the national economy. It has an action of 90 degrees of rotation, and the body is a sphere, with circular through-holes or channels through its axis.

Difference 3: Installation method.

Attention should be paid to the following matters in the installation and maintenance of the globe valve: 1. The globe valve operated by the handwheel and handle can be installed in any position of the pipeline. 2. Handwheels, handles and micro-moving mechanisms are not allowed to be used for lifting. 3. The flow direction of the medium should be consistent with the direction of the arrow shown on the valve body.

Attention should be paid to the installation of ball valves: 1) Remove the protective covers on both sides of the flange end and rinse and clean the valve when the valve is fully open. 2) Before installation, the whole machine should be tested according to the specified signal (electricity or gas) (to prevent vibration caused by transportation from affecting the performance), and the qualified rear line should be installed (the wiring is according to the circuit diagram of the electric actuator).

3) During installation, please do not use the actuator part of the valve as the lifting point to avoid damage to the actuator and accessories.

What is the difference between a patented ball valve and a globe valve?

Both valves are used for shut-off in the pipeline.

The characteristics of the gate valve are that the flow direction of the medium is not limited, the resistance is small, and the erosion of the sealing surface is very small when it is fully opened, but the opening height is generally high, and the sealing surface is easy to be damaged by friction, and it is difficult to maintain.

The globe valve is characterized by low opening resistance and low opening height, which is easy to maintain. However, the fluid resistance is large, the structure size is large, and the selection of DN greater than 200 is less, and the gate valve is generally selected.

Hope it helps!

It depends on where it is used, what medium, temperature, etc.

The types of gate valves and globe valves are relatively similar, but there are still differences, and the specific differences and selection analysis are as follows:

The axis of the valve stem of the globe valve is perpendicular to the sealing surface of the valve seat, the opening or closing stroke of the valve stem is relatively short, once the valve disc of the globe valve is in the open state, the valve seat and the sealing surface of the valve disc are no longer in contact, and have a very reliable shut-off action, making the globe valve products suitable for the use of medium cut-off or adjustment and throttling. Once the globe valve is open, there is no longer any contact between the seat and the sealing surface of the disc, so that the sealing surface of the globe valve is mechanically less worn. Since the seat and disc of most globe valves are relatively easy to repair or replace the sealing elements, there is no need to remove the entire valve from the pipeline, which is very suitable for the occasion where the valve and the pipeline are welded into one.

The flow direction of the medium through these valves changes, so the flow resistance of the globe valve is higher than that of other valves.

The advantage of the globe valve is that it is wear-resistant because the friction between the disc and the sealing surface of the valve body is less than that of the gate valve during opening and closing. The opening height of the globe valve is generally only 1 4 of the diameter of the seat channel, so it is much smaller than the gate valve.

Usually there is only one sealing surface on the valve body and disc, so the manufacturing process is relatively good and easy to maintain.

The selection principle of the globe valve is:

1. Weidun VTON high-temperature and high-pressure globe valves should be selected on the pipelines or devices of high-temperature and high-pressure mediums. Such as thermal power plants, nuclear power plants, petrochemical systems of high temperature, high pressure pipelines.

2. The globe valve is used in the pipeline where the convection resistance requirements are not strict. That is, where pressure loss is not considered much.

3. Small valves can be selected with VTON small-caliber globe valves, also known as needle valves, instrument valves, sampling valves, pressure needle valves, etc.

4. There is flow adjustment or pressure adjustment, but the adjustment accuracy is not high, and the diameter of the pipeline is relatively small, such as the nominal through 50mm pipeline, it is advisable to choose the Vton stop valve.

5. For small fertilizers and large fertilizers in synthetic industrial production, it is advisable to choose Weidun VTON high-pressure angle globe valve or high-pressure angle throttle valve with nominal pressure PN160 nominal pressure of 16MPa or PN320 nominal pressure of 32MPa.

6. In the desilization workshop in the production of alumina Bayer method, and on the pipeline that is easy to coke, it is easy to choose the direct flow stop valve or direct flow throttle valve with separate valve body, valve seat can be removed, and cemented carbide sealing pair.

7. In the water supply and heating projects in urban construction, the nominal passage through the smaller pipeline can be selected as the Weidun VTON globe valve, balance valve or plunger valve, such as the nominal passage through the pipeline less than 150mm.

8. Toxic and harmful media, flammable and explosive media, choose Weidun VTON imported bellows stop valve.

Gate valve: There is a plate in the valve body that is perpendicular to the flow direction of the medium, and the plate is lifted and lowered to achieve opening and closing. Features:

It has good airtightness, small fluid resistance, small opening and closing force, is widely used, and also has a certain flow adjustment performance, which is generally suitable for large-diameter official roads. It is suitable for large-caliber official roads.

Disc valve: the opening and closing parts are a disc-shaped, rotating valve around a fixed shaft in the valve body, characteristics: simple structure, small size, light weight, suitable for making larger diameter valves.

Because there are still problems with the sealing structure and materials, it is only used for low pressure and for transporting water, air, gas and other media!

Gate valves are most commonly used in equipment maintenance and are closed and cannot regulate the flow rate. The globe valve has the function of a gate valve, and also has the function of regulating the flow rate.