A butterfly valve is a regulating valve with a simple structure, which can also be used for cutting off and connecting media in low-pressure pipelines. A butterfly valve is a valve whose closing part is a disc, which rotates around the valve shaft to achieve the purpose of opening and closing. It mainly plays the role of cutting off and throttling the medium in the pipeline. A butterfly valve is applied to pipelines that deliver various corrosive and non-corrosive fluid media in engineering systems such as coal gas, natural gas, liquefied petroleum gas, city gas, cold and hot air, chemical smelting and power generation and environmental protection, which is used for adjusting and cutting the flow of the medium.
The selection principles of the butterfly valve are as follows:
1. A butterfly valve is suitable for piping systems with less stringent pressure loss requirements, because the pressure loss of a butterfly valve is greater than a gate valve and a ball valve.
2. A butterfly valve is applied to pipelines that require flow adjustment due to its function of adjusting flows.
3. A butterfly valve is usually used for pipelines of a temperature below 300℃ and nominal pressure below PN40. Because of the limitation of the structure and sealing material of the butterfly valve, it is not suitable for high-temperature and high-pressure pipelines.
4. A butterfly valve is applicable for places which require short structure length or pipelines with a size over DN1000, because the structure length of the butterfly valve is relatively short, and it can be made into a large diameter.
5. A butterfly valve is used for occasions that require fast opening and closing because it can be opened or closed by only rotating 90°.
A butterfly valve is good for regulating the flow. Its pressure loss in a pipeline is great, which is about triple higher than that of a gate valve. Therefore, not only the influence of the pressure loss of the pipeline system but also the robustness of the butterfly plate withstanding the pressure of the pipeline's medium at a closed state should be fully considered when selecting a butterfly valve. Moreover, the limitation of the working temperature of the elastic valve seat material at high temperatures also needs to be considered.
It is suitable to manufacture a butterfly valve of large diameters due to its structural features of short length, not great overall height, fast opening and closing, and good fluid control. Correctly choosing the size and type of butterfly valves is very important when they are used for controlling the flow, so they can properly and effectively work.
Generally, for throttling, regulating and muddy medium, the structure length is required to be short and the opening and closing speed fast (1/4r). The pressure difference should be small. A butterfly valve is recommended in this situation.
In the case of two-position adjustment, narrowed passages, low noise, cavitation and vaporization, a small amount of them leak into the atmosphere. When the medium is an abrasive medium, a butterfly valve can be used.
When butterfly valves are used under special conditions such as throttling, strict sealing requirements, severe wear, low temperatures and other conditions, a special design for triple eccentric or double eccentric with a specially designed metal seal and an adjusting device is required.
The center line butterfly valve is suitable for pipelines with zero gas test leakages, long service lives, fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil and various acid-base products with working temperatures of -10 to 150℃.
The soft-seal eccentric butterfly valve is suitable for the two-way opening, closing and adjustment of ventilation and dust removal pipelines. It is widely used in gas pipelines and waterways in metallurgy, light industry, electric power, and petrochemical systems.
A metal-to-metal line sealing double eccentric butterfly valve is suitable for urban heating, steam, water and gas, oil products, acid-base pipelines, as a regulating and intercepting device.
In addition to being used as a large-scale pressure swing adsorption (PSA) gas separation device program control valve, the metal-to-metal seal triple eccentric butterfly valve can also be widely used in petroleum, petrochemical, chemical, metallurgical, electric power and other fields. It is a substitute for a gate valve, a globe valve and other valves.
The selection principles of the butterfly valve are as follows:
1. A butterfly valve is suitable for piping systems with less stringent pressure loss requirements, because the pressure loss of a butterfly valve is greater than a gate valve and a ball valve.
2. A butterfly valve is applied to pipelines that require flow adjustment due to its function of adjusting flows.
3. A butterfly valve is usually used for pipelines of a temperature below 300℃ and nominal pressure below PN40. Because of the limitation of the structure and sealing material of the butterfly valve, it is not suitable for high-temperature and high-pressure pipelines.
4. A butterfly valve is applicable for places which require short structure length or pipelines with a size over DN1000, because the structure length of the butterfly valve is relatively short, and it can be made into a large diameter.
5. A butterfly valve is used for occasions that require fast opening and closing because it can be opened or closed by only rotating 90°.
A butterfly valve is good for regulating the flow. Its pressure loss in a pipeline is great, which is about triple higher than that of a gate valve. Therefore, not only the influence of the pressure loss of the pipeline system but also the robustness of the butterfly plate withstanding the pressure of the pipeline's medium at a closed state should be fully considered when selecting a butterfly valve. Moreover, the limitation of the working temperature of the elastic valve seat material at high temperatures also needs to be considered.
It is suitable to manufacture a butterfly valve of large diameters due to its structural features of short length, not great overall height, fast opening and closing, and good fluid control. Correctly choosing the size and type of butterfly valves is very important when they are used for controlling the flow, so they can properly and effectively work.
Generally, for throttling, regulating and muddy medium, the structure length is required to be short and the opening and closing speed fast (1/4r). The pressure difference should be small. A butterfly valve is recommended in this situation.
In the case of two-position adjustment, narrowed passages, low noise, cavitation and vaporization, a small amount of them leak into the atmosphere. When the medium is an abrasive medium, a butterfly valve can be used.
When butterfly valves are used under special conditions such as throttling, strict sealing requirements, severe wear, low temperatures and other conditions, a special design for triple eccentric or double eccentric with a specially designed metal seal and an adjusting device is required.
The center line butterfly valve is suitable for pipelines with zero gas test leakages, long service lives, fresh water, sewage, sea water, salt water, steam, natural gas, food, medicine, oil and various acid-base products with working temperatures of -10 to 150℃.
The soft-seal eccentric butterfly valve is suitable for the two-way opening, closing and adjustment of ventilation and dust removal pipelines. It is widely used in gas pipelines and waterways in metallurgy, light industry, electric power, and petrochemical systems.
A metal-to-metal line sealing double eccentric butterfly valve is suitable for urban heating, steam, water and gas, oil products, acid-base pipelines, as a regulating and intercepting device.
In addition to being used as a large-scale pressure swing adsorption (PSA) gas separation device program control valve, the metal-to-metal seal triple eccentric butterfly valve can also be widely used in petroleum, petrochemical, chemical, metallurgical, electric power and other fields. It is a substitute for a gate valve, a globe valve and other valves.
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