Double eccentric butterfly valve is usually called high performance butterfly valve, which is further improved on the basis of single eccentric butterfly valve, and is currently the most widely used butterfly valve.
1. Sealing principle of double eccentric butterfly valve
Since the rotary center of the valve plate (i.e. the center of the valve shaft) and the center line of the valve body form a dimension offset on the basis of single eccentric sealing butterfly valve, the sealing surface of the valve plate will be completely separated from the sealing surface of the seat when the double eccentric sealing butterfly valve is in the fully open state, and a larger gap will be formed between the disc sealing face and the seat sealing face than that between the single eccentric sealing butterfly valve to reduce the mechanical wear and scratch between the sealing surface of the butterfly valve sealing pair when the valve plate is opened and closed.
Generally, the sealing surface of the valve plate can be completely removed from the sealing surface of the seat when the valve plate is rotated from 0° to 8° to 12°, so the relative mechanical wear and extrusion angle travel between the valve plate and the sealing surface of the valve seat will be shorter in the process of opening and closing of butterfly valve, resulting in the reduction of mechanical wear and extrusion deformation, and the improvement of butterfly valve sealing performance.
Double eccentric butterfly valve is mainly used in water plant, power plant, steel smelting, chemical engineering, water source engineering, environmental facilities construction and other systems drainage. It is especially suitable for watercourse piping as adjusting and closing equipment. Compared with the center line butterfly valve, double eccentric butterfly valve is more resistant to high pressure with longer life and better stability. Compared with other valves, the larger the diameter, the lighter the material, and the lower the cost.
The double eccentric butterfly valves manufactured by ZECO Valve Group can be used as an opening and closing device, and can be converted to a horizontal butterfly valve. Welcome to purchase from us if you are interested in our products!