Tag Archive for: introduction

Posts

Detailed introduction of soft sealing butterfly valve-(1)

The butterfly plate of the soft sealing butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

ductile iron, DI, butterfly valve, manufacturer, center line, TH valve

disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened. The characteristics of the new type of high-life stainless steel butterfly valve and the problem of the butterfly valve during use, this type of valve should generally be installed horizontally in the pipeline.

Problems in use of soft sealing butterfly valve:
1. Since the multi-layer soft and hard stacked sealing ring is fixed on the valve plate, when the valve plate is normally open, the medium will wash its sealing surface positively, and the soft sealing tape in the metal sheet sandwich will directly affect the sealing performance after being washed.

2. Due to structural conditions, this structure is not suitable for valves with a diameter below DN200, because the overall structure of the valve plate is too thick and the flow resistance is large.

3. Due to the principle of the triple eccentric structure, the seal between the sealing surface of the valve plate and the valve seat depends on the torque of the transmission device to press the valve plate against the valve seat. In the state of positive flow, the higher the medium pressure, the tighter the sealing extrusion. When the flow channel medium flows back, as the medium pressure increases, the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the seal begins to leak.

high-performance soft sealing butterfly valve, characterized in that: the valve seat sealing ring is composed of multiple layers of stainless steel sheets on both sides of the soft T-shaped sealing ring.

The sealing surface of the valve plate and the valve seat is of oblique cone structure, and the temperature and corrosion resistant alloy material is built up on the oblique cone surface of the valve plate; the spring fixed between the pressure plate of the adjusting ring and the adjusting bolt of the pressure plate are assembled together. This structure effectively compensates for the tolerance zone between the shaft sleeve and the valve body and the elastic deformation of the valve stem under the medium pressure, and solves the sealing problem of the valve in the two-way interchangeable medium conveying process.

The sealing ring is composed of a soft T-shaped multi-layer stainless steel sheet on both sides, which has the dual advantages of metal hard and soft sealing. It has zero leakage sealing performance regardless of low temperature and high temperature. The test proves that in the positive flow state of the pool (the flow direction of the medium is the same as the rotation direction of the butterfly plate), the pressure of the sealing surface is produced by the torque of the transmission device and the action of the medium pressure on the valve plate. When the positive medium pressure increases, the tighter the oblique cone surface of the valve plate and the sealing surface of the valve seat are pressed, the better the sealing effect.

In the reverse flow state, the seal between the valve plate and the valve seat is pressed against the valve seat by the torque of the driving device. With the increase of the reverse medium pressure, when the unit positive pressure between the valve plate and the valve seat is less than the medium pressure, the deformation energy stored by the spring of the adjusting ring after being loaded compensates for the tight pressure of the sealing surface of the valve plate and the valve seat Play the role of automatic compensation.

Therefore, unlike the prior art, the utility model does not install a soft and hard multilayer sealing ring on the valve plate, but directly installs it on the valve body. Adding an adjustment ring between the pressure plate and the valve seat is a very ideal two-way hard sealing method. . It can replace gate valves and globe valves

Related news /knowledge:
Detailed introduction of soft sealing butterfly valve-(3);
How to choose the right butterfly valve (2);
Difference between Soft seal gate valve and hard seal gate valve;
Difference between soft seal butterfly valve and hard seal butterfly valve;

Introduction of U-shaped flange butterfly valve

What is U-shaped flange connection butterfly valve?
The U shaped butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. Moreover, it can be opened and closed quickly

U-type flange butterfly valve, ductile iron, DI, center line,

U-type flange butterfly valve, ductile iron, DI, center line,

by rotating 90°, and the operation is simple. At the same time, the valve has good fluid control characteristics.
The butterfly plate of the U type butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened.
The butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. Moreover, it can be opened and closed quickly by rotating 90°, and the operation is simple. At the same time, the valve has good fluid control characteristics. When the flange butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.
Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the defect of being limited by temperature.
If the butterfly valve is required to be used as a flow control, the main thing is to correctly choose the size and type of the valve. The structure principle of the butterfly valve is especially suitable for making large diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, water treatment, etc., but also used in cooling water systems of thermal power stations.
Commonly used butterfly valves include wafer butterfly valves and flange butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flanges.
When in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate. Valves with metal seals generally have a longer life than valves with elastic seals, but it is difficult to achieve a complete seal. Metal seals can adapt to higher operating temperatures, while elastic seals have the defect of being limited by temperature.
If the butterfly valve is required to be used as a flow control, the main thing is to correctly select the size and type of the valve. The structure principle of the butterfly valve is especially suitable for making large diameter valves. Butterfly valves are not only widely used in general industries such as petroleum, gas, chemical, water treatment, etc., but also used in cooling water systems of thermal power stations.
Commonly used butterfly valves include wafer butterfly valves and flange butterfly valves. Wafer type butterfly valve uses double-head bolts to connect the valve between two pipe flanges. Flange type butterfly valve has flanges on the valve, and bolts are used to connect the flanges at both ends of the valve to the pipe flanges.

Introduction of Flange butterfly valve

The butterfly valve is simple in structure, small in size and light in weight, and consists of only a few parts. Moreover, it can be opened and closed quickly by rotating

Double flange butterfly valve (3)

Double flange butterfly valve (3)

90°, and the operation is simple. At the same time, the valve has good fluid control characteristics. The butterfly plate of the butterfly valve is installed in the diameter direction of the pipeline. In the cylindrical passage of the butterfly valve body, the disc-shaped butterfly plate rotates around the axis, and the rotation angle is between 0° and 90°. When the rotation reaches 90°, the valve is fully opened. When the flange butterfly valve is in the fully open position, the thickness of the butterfly plate is the only resistance when the medium flows through the valve body, so the pressure drop generated by the valve is small, so it has better flow control characteristics. The butterfly valve has two sealing types: elastic seal and metal seal. Elastic sealing valve, the sealing ring can be embedded in the valve body or attached to the periphery of the butterfly plate.
Butterfly valves are divided into U type flange butterfly valves and double flange butterfly valves.

Introduction of flange butterfly valve:
The center of rotation of the butterfly plate of the flange butterfly valve (ie the center of the valve stem) is located on the center line of the valve body and the sealing surface section of the butterfly plate. The valve seat is made of synthetic rubber. When closed, the outer circular sealing surface of the butterfly plate squeezes the synthetic rubber valve seat, which makes the valve seat elastically deformed and forms an elastic force as the sealing pressure to ensure the sealing of the butterfly valve. Well-known domestic manufacturers include Shanghai Quangong Valve Equipment Co., Ltd. and Hunan Xinxing Hydropower Equipment Co., Ltd. Its company is a designated management and production enterprise by the Ministry of Machinery Industry, the Ministry of Chemical Industry, and China National Chemical Equipment Corporation. Its products have certain price advantages and technical advantages in the industry.

The sealing structure of the flange butterfly valve adopts polytetrafluoroethylene and synthetic rubber to form a composite valve seat. Its characteristic is that the elasticity of the valve is still provided by synthetic rubber and uses the characteristics of low friction coefficient, not easy to wear, and not easy to aging, so that The life of the butterfly valve is improved.

The sealing principle and structural characteristics of flanged butterfly valves are the same as those of ordinary centerline butterfly valves.

The sealing structure of flange butterfly valve adopts polytetrafluoroethylene, synthetic rubber and phenolic resin to form a composite valve seat, which makes the valve seat more elastic and stronger. At the same time, the butterfly plate is fully covered with PTFE, so that the butterfly plate has strong corrosion resistance.

Its sealing principle and structural characteristics are the same as ordinary centerline butterfly valve.

Related news /knowledges:
Related Information of flange butterfly valve;
The main classification and use conditions of valve sealing materials;
Introduction of U-shaped flange butterfly valve;
Wafer type double disc swing check valve introduction;