Optimization design of metallic seal pair structure for triple offset butterfly valve

The designers in China have not yet established the perfect design theory for describing the friction behavior in seal pair. To solve this, based on the features of triple offset butterfly valve (TOBV)´s structure, a reasonable mathematic model for describing seal pair structure is established. The relationship between the contact angle in 2D coordinate system and the friction behavior of the seal pair is established. Optimization design is achieved by taking the parameters of seal pair structure as design variables, and reciprocal of contact angle as the target function, and the criteria for no-interference closing/opening as the restriction conditions. The actual inspection shows that the parameters of the sample seal pair structure manufactured with the optimization design theory have achieved the best matching, the closing/opening friction moment is greatly reduced, and is near to the design requirement for zero friction, this has laid a sturdy foundation for establishing perfect design theory for metal sealed TOBV in China.