The existing problems in using three eccentric metal hard sealing
一、As the multi-layer hard and soft stacked sealing ring fixed to the valve plate, when the valve plate in normal open state, media form positive erosion to its sealing surface, and after the soft-sealing tape laminated in metal sheets erosion, the direct impact on sealing performance.
二、Limited by the structural conditions, this structure are not applied to use as the valve below DN200, because the overall plate structure is too thick, large flow resistance.
三、due to three eccentric structure principle, the sealing between the valve plate sealing surface and the seat depends on the transmission device torque to press valve plate to the seat. When it in positive flow state, the higher media pressure the more tightly sealing squeeze. When the flow medium is upstream, with medium pressure increases, when the unit positive pressure between the valve plate and seat is less than the medium pressure, the sealing starts to leak out.
High-performance three eccentric two-way hard sealed butterfly valve, its characteristics are: the described seat sealing ring is composed by soft T-shaped sealing ring two sides multi-layer stainless steel sheet. Valve plate and valve seat sealing surface are the oblique cone structure, bead welded anti-temperature, corrosion resistant alloy materials on the valve plate oblique cone surfacing; the spring fixed between regulating ring pressplate and matching the regulative bolts of the pressplate structure.
This structure effectively compensate for the tolerance range between the sleeve and the body, valve stem elastic deformation in the medium pressure, solving the valve sealing problems exist in the two-way medium exchange transmission process. Using soft T-shaped two sides multi-layer stainless steel sheet to compose sealing ring and with dual advantages of metal hard sealing and soft sealing, no matter in the low and high temperature cases, both with zero leakage sealing performance.
