Structural characteristics, working principle and

Structural characteristics, working principle and classification of ventilation butterfly valve

structural characteristics

1 it adopts a new structural form of welding midline disc plate and short structural steel plate. It is designed and manufactured with compact structure, light weight, easy to install, small flow resistance and large flow capacity. Easy operation, no connecting rod, bolt, etc. in 2, reliable operation and long service life. It can be installed in multiple stations and is not affected by the flow direction of the medium

it is widely used in the production processes of building materials, metallurgy, mining, electric power, etc. the temperature of the medium is ≤ 300 ℃ and the nominal pressure is 0.1MPa. The pipeline has established a research and development center with Qingdao University of science and technology. Purpose: This butterfly valve is a non airtight butterfly valve. It is used to connect, open and close or adjust the medium quality

working principle

the ventilation butterfly valve is driven by the motor to drive the actuator, so that the disc can rotate freely within the range of 90 ° to achieve the purpose of opening and closing or adjusting the medium flow. As a component used to realize the on-off and flow control of pipeline system, rubber lined butterfly valve has been widely used in many fields such as petroleum, chemical industry, metallurgy, hydropower and so on. In the well-known butterfly valve technology, the sealing form mostly adopts the sealing structure, and the sealing materials are rubber, polytetrafluoroethylene, etc. Due to the limitation of structural characteristics, it is not suitable for industries such as high temperature resistance, high pressure resistance, corrosion resistance and wear resistance. The existing advanced butterfly valve is a three eccentric metal hard seal butterfly valve. The valve body and valve seat are connected components, and the sealing surface of the valve seat is overlaid with temperature resistant and corrosion-resistant alloy materials. The multi-layer soft laminated seal ring is fixed on the valve plate. Compared with the radical butterfly valve, this kind of butterfly valve has the advantages of high temperature resistance, light operation, no friction in opening and closing, and compensates for the sealing with the increase of the torque of the transmission mechanism when closing, which improves the sealing performance of the butterfly valve, introduces four key links and key projects, and extends the service life

classified construction of ventilation butterfly valve and key points of device 1. The position, height and inlet and outlet direction of the device must meet the design requirements. Note that the direction of medium flow should be consistent with the direction of the arrow marked on the valve body, and the connection should be firm and tight. 2. The appearance inspection must be carried out before the valve device, and the nameplate of the valve should comply with the current national specification "general valve marks" gb12220. For valves whose working pressure is greater than 1.0MPa and which play a cut-off role on the main pipe, strength and tightness tests should be carried out before installation, and they can be used only after passing the tests. During the strength test, the test pressure is 1.5 times the nominal pressure, and the continuous time is not less than 5min. The valve shell and packing are qualified if there is no leakage. During the tightness test, the test pressure is 1.1 times of the nominal pressure; The duration of the test shall meet the requirements of GB50243

ventilation butterfly valves are classified according to working pressure.

1 the working pressure of vacuum butterfly valves is the same as that of manual hydraulic valves, and the price is also more expensive than that of domestic ones. A sample of material testing machine is lower than that of standard reactor 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 100--80.0mpa butterfly valve

5 ultra high pressure butterfly valve. Nominal pressure PN ＞ 100MPa butterfly valve

ventilation butterfly valve is classified according to working temperature

1 high temperature butterfly valve. T> 450 ℃ butterfly valve

2 Warm butterfly valve. 120c ＜ t ＜ 450C butterfly valve

3 normal temperature butterfly valve. - 40C ＜ t