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The advantages and disadvantages of butterfly valves

July 10, 2020

1. Convenient opening and closing, labor saving, low fluid resistance, and can be operated frequently.

wafer type butterfly valve, NBR seat (11)

2. The structure is simple, the external dimensions are small, the structural length is short, the volume is small, and the weight is light. It is suitable for valves with large diameter.

3. Mud can be transported, and the least liquid is accumulated in the pipe mouth.

4. Under low pressure, a good seal can be achieved.

5. Good adjustment performance.

6. When fully opened, the effective flow area of the valve seat channel is large, and the fluid resistance is small.

7. The opening and closing torque is small, because the butterfly plates on both sides of the rotating shaft are basically the same under the action of the medium, and the direction of generating torque is opposite, so the opening and closing are more labor-saving.

8. The sealing surface material is generally rubber, plastic, so the low-pressure sealing performance is good.

9. Easy installation.

10. Flexible and labor-saving operation, you can choose manual, electric, pneumatic, hydraulic mode.

Disadvantages of butterfly valve:

1. The operating pressure and operating temperature range are small.

2. Poor sealing.

Butterfly valves can be divided into offset plate type, vertical plate type, inclined plate type and lever type according to the structure.

According to the sealing form, it can be soft-sealed or hard-sealed. The soft seal type generally uses a rubber ring seal, and the hard seal type usually uses a metal ring seal.

According to the connection type, it can be divided into flange connection and wafer connection; according to the transmission mode, it can be divided into manual, gear transmission, pneumatic, hydraulic and electric.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

Structure and characteristics of butterfly valve

July 9, 2020

Butterfly valve is mainly composed of valve body, valve stem, butterfly plate and sealing ring. The valve body is cylindrical, with a short axial length and a built-in butterfly plate.

Double flange butterfly valve (16)

Features of butterfly valve:
1. The butterfly valve has the characteristics of simple structure, small size, light weight, low material consumption, small installation size, rapid switching, 90° reciprocating rotation, and small driving torque. It is used to cut off, connect, and adjust the medium in the pipeline. Has good fluid control characteristics and closed sealing performance.

2. The butterfly valve can transport mud and has the least liquid accumulation at the pipe mouth. At low pressure, a good sealing effect can be achieved. Good adjustment performance.

3. The streamlined design of the butterfly plate makes the fluid resistance loss small, which can be described as an energy-saving product.

4. The valve stem is a through-rod structure. After quenching and tempering, it has good comprehensive mechanical properties, corrosion resistance and scratch resistance. When the butterfly valve is opened and closed, the valve stem only rotates and does not move up and down. The filler of the valve stem is not easy to damage and the seal is reliable. It is fixed with the taper pin of the butterfly plate, and the outgoing end is designed to prevent the outgoing type, so as to prevent the valve rod from collapsing when the connection between the valve rod and the butterfly plate is accidentally broken.

5. Connection methods include flange connection, wafer connection, butt welding connection and lug wafer connection. The driving form includes manual, worm gear transmission, electric, pneumatic, hydraulic, electro-hydraulic linkage and other actuators, which can realize remote control and automatic operation.

You can check the types and structures of butterfly valve on this page: Butterfly Valve

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

How does a butterfly valve work?

July 8, 2020

A butterfly valve is a valve that uses a disc-type opening and closing part to reciprocate around 90° to open, close, or regulate the flow of media. Butterfly valves are not only simple in structure, small in size, light in weight, low in material consumption, small in installation size, small in driving torque, easy in operation and fast, but also can have good flow adjustment function and close sealing characteristics at the same time. One of the fastest valve varieties. Butterfly valves are one of the fastest growing valve varieties in the past decade.

Butterfly valves are widely used. The variety and quantity of its use are still continuing to expand, and develop to high temperature, high pressure, large diameter,

Double flange butterfly valve (16)

high sealing, long life, excellent adjustment characteristics, and multi-function development of one valve. Its reliability and other performance indicators have reached a high level. With the application of chemically resistant synthetic rubber on butterfly valves, the performance of butterfly valves has been improved. Because synthetic rubber has the characteristics of corrosion resistance, erosion resistance, dimensional stability, good resilience, easy forming, and low cost, and can choose different performance synthetic rubber according to different use requirements to meet the working conditions of butterfly valves.

Polytetrafluoroethylene (PTFE) has strong corrosion resistance, stable performance, not easy to aging, low friction coefficient, easy to form, stable in size, and can be filled and added with appropriate materials to improve its comprehensive performance, resulting in better strength and friction coefficient The lower butterfly valve sealing material overcomes the limitations of synthetic rubber. Therefore, polymer polymeric materials represented by PTFE and its filling modified materials have been widely used in butterfly valves. Therefore, the performance of butterfly valves has been further improved, resulting in a wider temperature and pressure range and sealing performance, reliable and longer life butterfly valve.

butterfly valve working diagram-3D GIF animated presentation

In order to meet the requirements of industrial applications such as high and low temperature, strong erosion, and long life, metal seal butterfly valves have been greatly developed. With the application of high temperature resistance, low temperature resistance, strong corrosion resistance, strong erosion resistance, and high strength alloy materials in butterfly valves, metal sealed butterfly valves have been widely used in industrial fields such as high and low temperature, strong erosion, and long life. The emergence of butterfly valves with large diameter (9~750mm), high pressure (42.0MPa) and wide temperature range (-196~606℃) has brought the technology of butterfly valves to a whole new level.

When the butterfly valve is fully opened, it has a small flow resistance. When the opening is between about 15°~70°, the sensitive flow control can be performed, so the application of butterfly valves is very common in the field of large-diameter adjustment. Because the movement of the butterfly plate of the butterfly valve is wiping, most butterfly valves can be used for media with suspended solid particles. Depending on the strength of the seal, it can also be used in powder and granular media. Butterfly valves are suitable for flow regulation. Because the pressure loss of the butterfly valve in the pipe is relatively large, about three times that of the gate valve, when selecting the butterfly valve, the influence of the pressure loss of the pipeline system should be fully considered, and the strength of the butterfly plate to withstand the pressure of the pipeline medium when closing . In addition, the working temperature limit of the elastic seat material must be considered at high temperatures.

The structure length and overall height of the butterfly valve are small, the opening and closing speed is fast, and it has good fluid control characteristics. The structure principle of butterfly valve is most suitable for making large-diameter valve. When the butterfly valve is required for flow control, the most important thing is to correctly select the size and type of the butterfly valve so that it can work properly and effectively. Generally, in throttling, regulating control and mud medium, the structure length is short, the opening and closing speed is fast, and cut off at low pressure (small pressure difference). It is recommended to use a butterfly valve. Butterfly valves can be used when there are two-position adjustment, reduced diameter channels, low noise, cavitation and vaporization, a small amount of leakage into the atmosphere, and abrasive media.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

How to achieve internal and external anti-corrosion of pneumatic valves

July 2, 2013

Pneumatic valve using pneumatic actuators, for which Air (or other gas) pressure is the source of power. Air pressure acts on the piston or bellows diaphragm, which produces a linear force on the valve stem. Pneumatic actuator is a kind of Power-operated actuators (using pneumatic, hydraulic or electric power), can remotely adjust valves, or quickly operate large valves.

In order to effectively guarantee the use efficiency of the pneumatic valve, and also to effectively extend the service life of the pneumatic valve, the internal and

Pneumatic actuator (2)

external corrosion protection of the pneumatic valve is a very important part of its use process, then we should pay attention to the main points for the internal and external corrosion protection of the pneumatic valve And what are the main items in the operation, we will give a brief introduction to you in the following article.

1. The inside of the valve body of the pneumatic valve and all parts of the valve plate require comprehensive corrosion protection. On the one hand, it will not rust in water, and there will be no electrochemical corrosion between the two metals; on the other hand, the smooth surface reduces the resistance to water.

2. Hygienic requirements of epoxy resin or paint for anti-corrosion of pneumatic valve body shall have a test report from corresponding authority. The chemical and physical properties should also meet the relevant requirements.

3. The inside and outside of the valve should first be shot blasted to remove sand and rust, and strive to

pneumatic valve structure

electrostatically spray powdered non-toxic epoxy resin with a thickness of more than 0.3mm. When it is difficult to electrostatically spray non-toxic epoxy resin for extra large valves, similar non-toxic epoxy paint should also be brushed and sprayed.

In addition, the pneumatic valve should also pay attention to the necessary maintenance during daily storage and transportation, including:

1. The pneumatic valve should be stored in a dry and ventilated room, and both ends of the passage must be blocked.
2. Valves stored for a long period of time should be checked regularly to remove dirt and apply anti-rust oil on the processed surface.
3. After the pneumatic valve is installed, regular inspections should be carried out. The inspection items are as

D673H-16C-stainless steel pneumatic triple eccentric butterfly valve

follows:
1) The wear of the sealing surface;
2) Trapezoidal thread wear of the stem and stem nut;
3) Whether the packing is out of date and invalid, and if damaged, it should be replaced in time.

TH Valve is one of the largest butterfly valve, check valve manufacturers in China. Now we have our own independent R & D, manufacturing,

assembly and warehousing workshops; we have professional pre-sale and after-sale technical support and perfect services.

TH Valve is a professional manufacturer of butterfly valve, gate valve, check valve, globe valve, knife gate valve, ball valve with API, JIS, DIN standard, used in Oil, Gas, Marine industry, Water supply and drainage, fire fighting, shipbuilding, water treatment and other systems, with Nominal Diameter of DN50 to DN1200, NBR/EPDM/VITON, Certificates & Approvals: DNV-GL, Lloyds, DNV, BV, API, ABS, CCS. Standards: EN 593, API609, API6D

The advantages and disadvantages of butterfly valves

Structure and characteristics of butterfly valve

How does a butterfly valve work?

How to achieve internal and external anti-corrosion of pneumatic valves

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