Metal seal butterfly valve:
Adopt metal sealing surface and other rigid materials to achieve zero leakage requirements, which can be used for medium high temperature, medium high pressure projects.
1. The operating temperature can meet the requirements of medium and high temperature (200℃+-);
2. High pressure, wear resistance, long service life
3. High cost. Compared with ventilated butterfly valve and soft seal butterfly valve, its cost is relatively high, and the configured actuator requires a larger model, resulting in a higher overall cost. If there is no special requirement, it is rarely used.
For environmental protection projects requiring zero leakage and slightly higher temperature and pressure, this kind of valve is a good choice, but cost control is unavoidable.
Ventilated butterfly valve:
As the name suggests, through the wind to the gas medium of the valve. The form structure is simple, easy to operate, can be customized according to user needs, usually in the form of round and square.
1. The ventilation butterfly valve has the advantages of low cost, simple technology, small torque, small actuator type, and large price advantage on the whole;
2. The temperature is not limited, the selection of different materials, the use of temperature can be at room temperature (< 100℃), high temperature (200℃+-) ultra high temperature (500℃+-);
3. Long service life, ventilation butterfly valve structure is simple, easy to maintain;
4. With a certain leakage rate, a retainer is added to the inner wall of the valve body. So that the valve plate and the retainer are closely fitted to reduce leakage under the closed state of the valve, and the leakage can be controlled at about 1%. For the waste gas treatment project is within the control scope;
Based on these characteristics, the ventilated butterfly valve is widely recognized and has a high market share. Such valves are mostly used in exhaust gas treatment projects such as adsorption and desorption and catalytic combustion. However, for engineering equipment containing toxic gas in the medium, it is necessary to choose carefully.