Triple Eccentric butterfly valve add a third angular eccentric based on double eccentric structure.
The three offsets below:
The first offset is that the valve shaft is behind the disc shaft so that the seal can completely close the entire valve seat.
The second offset is that the center-line of the valve shaft is offset from the pipe and valve center-line to avoid interference from valve opening and closing.
The third offset is that the seat cone axis deviates from the center-line of the valve shaft, it ensure the sealing ring of the disc can be separated or touched with seat rapidly so that friction and squeeze between seat and sealing ring will be eliminated.and Achieves a uniform compression seal around the entire seat.
The traditional hard seal butterfly valve sealing performance is not guaranteed, and the leakage amount is large. In order to change this situation, the hard seal butterfly valve has been through many iterations, and a triple eccentric butterfly valve (also known as triple offset butterfly valve) has been invented.
Triple eccentric butterfly valves are characterized in that the high temperature and corrosion resistant alloy material is welded on the sealing surface layer of the valve seat, and the multi-layer soft sealing ring is fixed on the butterfly plate. This process makes the triple eccentric butterfly valve more resistant to high temperature, high pressure and corrosion compared with traditional butterfly valves.ensure perfect tightness in steam, gas, chemical, petrochemical and cryogenic applications.
Specifically, the benefits of using a triple eccentric structure for a hard-seal butterfly valve are:
The unique design of the triple eccentricity makes the metal hard seal start more easily. When the valve is opened and closed, there is no friction between the disc and the valve body during the rotation process. When the valve is closed, the torque of the transmission mechanism can increase to provide compensation. This greatly improves the sealing performance of the triple eccentric butterfly valve and prolongs the service life of it.
These valves are available in wafer type, lug type and double flanged execution.