The common triple-eccentric butterfly valve has a seal ring composed of two or more layers of metal sheets and non-metal sheets, and is fixed on disc by pressing ring and bolts. The butterfly valve of this structure can only be applied to working conditions at normal temperature and pressure, and the medium is non-corrosive, due to the physical and chemical properties of the non-metal material on the seal ring. When the pressure and flow rate in pipeline is high,and the disc is partially opened or fully opened, the high-speed fluid will damage the seal ring on the disc, and cause the non-metallic interlayer on the seal ring to wear or even fall off. This will affect valve sealing seriously. When the medium is corrosive, the non-metallic interlayer on the sealing ring is susceptible to the corrosion of the medium,thus causes leakage on valve.
To improve the inadequacies of triple-eccentric butterfly valve with multi-layer metal seal ring, we have developed metal to metal seat,which has remarkable features as below,
1. The seal ring is totally made of metal material and there is no interlayer of non-metallic materials such as PTFE, graphite, rubber asbestos board, etc. When the valve is fully open or partially open, the seal ring will not be damaged by the high flow,thus the valve’s service life is greatly extended.
2. The seal ring, made of metal material, which can be applied in hard working conditions, which may be of high temperature max 800°C, low temperature min -196°C, high pressure max PN260/Class 1500,and corrosive medium
