Ventilation butterfly valve is a kind of non closed butterfly valve. The ventilation butterfly valve is use in the dust containing cold air or hot air gas pipeline of the ventilation and environmental protection engineering in the chemical industry, building materials, power station, glass and other industries as the pipeline control device for regulating the flow or cutting off the gas medium. This kind of valve should install horizontally in the pipeline.
1. Structure features of ventilation butterfly valve:
1. The new type of structure is design and manufacture by using the middle line type disc plate and short structure steel plate welding. Which has the advantages of compact structure, light weight, convenient device, small flow resistance, large flow capacity and light operation.
2. There is no connecting rod and bolt inside, which is reliable and long service life. It can install in multiple stations, not affected by the flow direction of media.
2. Application of ventilation butterfly valve:
The ventilation butterfly valve is a kind of non airtight butterfly valve. Which is widely use in the production process of building materials, metallurgy, mining, electric power, etc. The medium temperature is ≤ 300 ℃ and the nominal pressure is 0.1MPa. It is use to connect, open and close or adjust the medium quality.
3. Working principle of ventilation butterfly valve:
The ventilation butterfly valve is driven by the motor to drive the actuator. So that the disc plate can rotate freely within 90 ° to achieve the purpose of opening and closing or regulating the medium flow.
4. Key points of ventilation butterfly valve:
1. The position, height and direction of inlet and outlet of the device must meet the design requirements. It should note that the direction of medium flow should be consistent with the direction of arrow marked on the valve body, and the connection should be firm and tight.
2. Visual inspection must carry out before the valve device, and the nameplate of the valve shall comply with the provisions of the current national code general valve marking gb12220. For the valve whose working pressure is greater than 1.0MPa and which plays a role of cutting off on the main pipe. The strength and tightness performance test shall carry out before the device. And the valve can only be used after it is qualified. During the strength test, the test pressure shall be 1.5 times of the nominal pressure. And the valve shell and packing shall have no leakage for no less than 5min. During the tightness test, the test pressure shall be 1.1 times of the nominal pressure. The test duration shall meet the requirements of GB50243.