What is an air duct butterfly valve and what are they made of?

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.

Ventilation butterfly valves, carbon steel and stainless steel are available. It also depends on the medium, which is metallurgical.

The air duct butterfly valve should be commonly referred to as the ventilation butterfly valve, which is generally used to adjust the air volume and temperature according to the requirements, which is convenient for use in the hot and cold seasons.

Some are required to adjust the air volume and temperature according to the requirements.

It is convenient for use in both hot and cold seasons.

There is also the fact that this air duct is multi-functional.

Such as exhaust and smoke exhaust.

Close the damper at all times, otherwise it will help the fire.

Not good for fire extinguishing.

Butterfly Valves - Classification.

1. Classified according to the structural form: (1) central seal butterfly valve, (2) single eccentric seal butterfly valve, (3) double eccentric seal butterfly valve, (4) triple eccentric seal butterfly valve.

2 Classification according to the material of the sealing surface: (1) Soft seal butterfly valve. 1) The sealing pair is composed of non-metallic soft materials to non-metallic soft materials. 2) The sealing pair is composed of metal hard material to non-metal soft material.

2) Metal hard seal butterfly valve. The sealing pair is composed of a hard metal material to a hard metal material. 3. Classification according to sealing form: (1) forced sealing butterfly valve 1) elastic sealing butterfly valve.

The sealing specific pressure is generated by the elasticity of the valve seat or valve plate when the valve is closed, and the valve seat or valve plate is 2) plus torque to seal the butterfly valve. The specific pressure of the seal is generated by the torque applied to the valve shaft (2) Pressure seal butterfly valve. The sealing specific pressure is generated by the pressure of the elastic sealing element on the valve seat or valve plate.

The sealing specific pressure is automatically generated by the pressure of the medium.

4 Classification by working pressure (1) Vacuum butterfly valve. Butterfly valves with working pressures lower than those of the standard stack atmospheric calendar. (2) Low-pressure butterfly valve.

Nominal pressure PN 1 6MPa butterfly valve. (3) Medium pressure butterfly valve. The nominal pressure pn is 2 5--6 4MPa butterfly valve.

4) High pressure butterfly valve. Butterfly valve with nominal pressure pn. (5) Ultra-high pressure butterfly valve.

Butterfly valve with nominal pressure PN 100MPa. 5 Classification according to working temperature: (1) High temperature butterfly valve. T 450 C butterfly valve (2) medium temperature butterfly valve.

120 C t 450 C butterfly valve (3) Normal temperature butterfly valve. A 40c t<; 120 C butterfly valve (4) cryogenic butterfly valve. A 100 t a 40 C butterfly valve (5) ultra-low temperature butterfly valve.

T 100 C butterfly valve 6 is classified according to the connection method: (1) pair clamp butterfly valve. (2) Flanged butterfly valve. (3) Lug butterfly valve.

4) Welded butterfly valve.

Structural classification of butterfly valves: centerline to clamp butterfly valves, centerline flange butterfly valves, single eccentric butterfly valves, double eccentric butterfly valves, variable eccentric butterfly valves, soft seal butterfly valves, hard seal butterfly valves.

The drive classification of butterfly valves: handle, worm gear, electric, pneumatic, electromagnetic, electrohydraulic, electrohydraulic, hydraulic, gas-hydraulic.

There are clamp-type butterfly valves and flange butterfly valves, manual, pneumatic, electric, [Zhengzhou Xingyang Water Supply Equipment General Factory].

When it comes to the material of the valve body, the material of the raft, the rubber, the shaft, the price is also different.

Butterfly Valves - Classification.

Structure: (1) Center Seal Butterfly Valve (2) Single Eccentric Seal Butterfly Valve (3) Double Eccentric Seal Butterfly Valve (4) Triple Eccentric Seal Butterfly Valve.

Sealing surface material (1) Soft-seal butterfly valve. 1) The sealing pair is composed of non-metallic soft materials to non-metallic soft materials. 2) The sealing pair is composed of metal hard material to non-metal soft material.

2) Metal hard seal butterfly valve. The sealing pair is composed of a hard metal material to a hard metal material.

Sealing form (1) Forced seal butterfly valve 1) Resilient seal butterfly valve. The specific pressure of the seal is generated by the elasticity of the seat or disc when the valve is closed. 2) External torque seal butterfly valve.

The sealing pressure is generated by the torque applied to the valve shaft. (2) Pressurized sealed butterfly valve. The specific pressure of the seal is generated by the pressurization of the elastic sealing element on the seat or disc.

3) Automatic sealing butterfly valve. The sealing specific pressure is automatically generated by the pressure of the medium.

Operating pressure (1) Vacuum butterfly valve. Butterfly valves with working pressures lower than those of the standard stack atmospheric calendar. (2) Low-pressure butterfly valve.

Nominal pressure PN 1 6MPa butterfly valve. (3) Medium pressure butterfly valve. The nominal pressure pn is 2 5--6 4MPa butterfly valve.

4) High pressure butterfly valve. The nominal pressure pn is 10. 0--80 0mpa butterfly valve.

(5) Ultra-high pressure butterfly valve. Butterfly valve with nominal pressure PN 100MPa.

Operating temperature (1) High temperature butterfly valve. T 450 C butterfly valve (2) medium temperature butterfly valve. 120 C (3) Ambient Butterfly Valve. A 40c a 100

The air volume control valve is an indispensable air conditioning terminal fitting in the ventilation, air conditioning and air purification projects of industrial plants and civil buildings, which is generally used in air conditioning and ventilation system pipes to adjust the air volume of branch pipes, and can also be used for mixed adjustment of fresh air and return air.

First, the characteristics of the air volume control valve.

l) The size of the pipe of the split multi-leaf air volume control valve is the same as that of the rectangular air duct specified in the national ventilation duct standardization.

2) The blades of the air volume control valve are split and smooth open, which are used as control valves in ventilation, air conditioning and air purification systems.

3) Through the test measurement, the air tightness of the air volume control valve is good, its relative air leakage is about 5%, and the adjustment performance is good.

2. Structural characteristics of air volume control valve.

l) The air volume control valve is unified into four specifications in the blade width, the blade shape is diamond-shaped double blade, and the blade adopts soft lap joint, so the sealing performance is good.

3) The valve body structure of the air volume control valve is cold-rolled with 2 mm galvanized sheet, and then welded with carbon dioxide gas protection or processed and welded by ordinary Q235 plate; The blades are cold-rolled with 1 mm galvanized sheet for corrugated shape, two pieces of synthetic spot welded square shaft, or 2 mm G235 steel plate cold pressed forming, and a single piece of punched socket square shaft or welded round shaft.

4) The regulating valve is divided into manual and electric, according to the materials used: carbon steel plate, galvanized plate, aluminum alloy plate, stainless steel plate, four types, the valve body structure and specifications are the same.

3. Scope of application of air volume control valve.

It is widely used in the HVAC system of industrial and mining and civil buildings, and it is one of the key equipment to control the ventilation mode in various environments. Its main characteristics are flexible operation, low noise, small leakage, (closed leakage< wide operating temperature area, reliable structure, safe and convenient.

1. Split closed multi-leaf control valve.

It can be divided into two types: manual and electric, because of the use of split blades, the air flow is more uniform, and the manual connecting rod can drive the blades to rotate, adjust the flow through the air flow, and at the same time, it can be completely closed so that the air flow can not pass. Because the edge of the blade is embedded with a sealing strip, it can ensure its tightness when closing, and has the advantages of low resistance and small air leakage. The multi-leaf control valve is mostly installed on the main air duct and the branch air duct, and the electric multi-leaf control valve is to install an electric actuator on the main shaft driven by the control valve, turn on the power supply, adjust the position of the actuator pointer, make it rotate clockwise and counterclockwise, and drive the valve blade connected on the main shaft to open and close.

When the manual release button on the actuator is pressed, the manually adjustable valve vane can also be adjusted from a fully closed to a fully open position. The multi-leaf control valve with electric actuator is mostly installed at the air inlet of the new fan supporting the air conditioner in the precision machine room, and the power supply line is interlocked with the motor of the fan in the unit, that is, the fresh air duct valve is also closed at the same time when the fan of the unit is shut down. When used in winter, it will avoid cold air entering the unit to freeze the water in the heat exchanger after the fresh fan is shut down, and at the same time, it can also prevent the fire from entering the air duct and increasing the fire after the fire breaks out in the building.

There are many specifications of multi-leaf control valves, which are generally installed on the air duct and have the same cross-sectional size as the air duct. When using a manual multi-lobe control valve, when the air volume needs to be adjusted, the blades should be adjusted and opened at a certain angle, and then the lock nut should be used to fix them. Electric actuators should be selected products with small size, large torque, high control accuracy, high reliability and easy installation.

2. Butterfly valve. The butterfly valve has a simple structure and easy operation, and plays the role of opening and closing or adjusting the air volume, but the opening resistance is larger than that of the leaf control valve, and it is generally installed on the branch air duct that enters the air conditioner of the precision computer room. According to the structural form, there are two types of butterfly valves: zipper type and handle type.

3. Three-way control valve.

The three-way control valve is mainly used at the rectangular straight through three-way pipe or trouser fork pipe to adjust the air volume of the branch pipe, and the three-way control valve has two types: handle type and tie rod type.

4. Plug-in valve.

The plug-in valve is mostly used at the outlet of the centrifugal fan as a fan start-up, also known as the plug-in start valve, which is rarely used in the ventilation and air conditioning pipeline because of the large opening resistance.

There are many ways to classify butterfly valves, and they are divided into soft seal butterfly valves and hard seal butterfly valves according to their sealing materials.

Soft Seal Butterfly Valve: The sealing pair is composed of non-metallic soft materials to non-metallic soft materials, or metal hard materials to non-metallic soft materials.

Hard Seal Butterfly Valve: The sealing pair is composed of a metal hard material against a metal hard material.

Difference Between Soft Seal Butterfly Valve and Hard Seal Butterfly Valve:

1. Soft seal butterfly valves are mostly centerline type hard seals, and most of them are single eccentric, double eccentric, and triple eccentric butterfly valve structures.

2. Soft seal is used in room temperature environment. Hard seals can be used in low temperature, normal temperature, high temperature and other environments.

3. The soft seal is used for low pressure-normal pressure, and the hard seal can also be used for medium and high pressure.

4. The sealing performance of soft seal and triple eccentric hard seal butterfly valve is relatively good, and the triple eccentric butterfly valve can maintain a good seal in the high pressure and high temperature environment.

Because of their different characteristics, soft seal butterfly valves are suitable for two-way opening and closing and adjustment of ventilation and dust removal pipelines, water treatment, light industry, petroleum, chemical and other industries. Hard seal butterfly valves are mostly used in heating, gas supply, gas, oil, acid and alkali environments.

Classification of butterfly valves.

1. According to the different connection forms, it can be divided into clamp type butterfly valve, flange type butterfly valve, welded butterfly valve, threaded butterfly valve, clamp butterfly valve and so on. The most commonly used connection forms are the clamp-on butterfly valve and the flanged butterfly valve.

2. According to the different transmission modes, it can be divided into handle butterfly valve, turbine butterfly valve, pneumatic butterfly valve, electric butterfly valve, hydraulic butterfly valve, solenoid valve, etc. The most common transmission methods are handle, turbine, pneumatic and electric. Whereas, handle butterfly valves and turbine butterfly valves are collectively referred to as manual butterfly valves.

3. According to the different materials of the sealing surface, it can be divided into soft seal butterfly valve and hard seal butterfly valve. The sealing performance of the soft seal butterfly valve is better than that of the hard seal butterfly valve, and the common materials for the sealing surface of the soft seal butterfly valve are EPDM, nitrile rubber, and PTFE. Hard-sealed butterfly valves are mainly used in high temperature and high pressure working conditions.

4. According to the different structural forms, it can be divided into midline butterfly valve, single eccentric butterfly valve, double eccentric butterfly valve and triple eccentric butterfly valve. Among them, the midline butterfly valve is generally soft sealed; Eccentric butterfly valves are hard sealed. The triple eccentric butterfly valve is the best performing valve at present, which not only has the excellent sealing performance of the soft seal butterfly valve, but also has the characteristics of high temperature and high pressure corrosion resistance of the hard seal butterfly valve.

5. According to the different working pressures, it can be divided into vacuum butterfly valve (nominal pressure is lower than the standard atmospheric pressure), low-pressure butterfly valve (nominal pressure pn medium pressure butterfly valve (nominal pressure high-pressure butterfly valve (nominal pressure ultra-high pressure butterfly valve (nominal pressure pn 100MPa).

The role of the butterfly valve.

Butterfly valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, slurries, oils, liquid metals and radioactive media. It mainly plays the role of cutting and throttling on the pipeline. The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body, so as to achieve the purpose of opening and closing or adjusting.

Butterfly valve is usually used in industrial production pipelines, as the control component of the pipeline, the butterfly valve is very important, it can cut off the flow of the medium in the pipeline, or adjust the size of the medium flow in the pipeline. At present, butterfly valves have been widely used in water conservancy engineering, water treatment, petroleum, chemical industry, urban heating and other general industries in the production line, as well as in the condenser and cooling water system of thermal power station.