The Research On Advanced Leak Tight Tructure And Material For The Valve

This article makes the research on the leak tight structure of power plant valve,especially for the "double hardfacing structure" of anti-scour globe valve used for boilerblowdown and "the sealing with the flexible hardfacing" of full-bore type safety valve forkeeping the power plant boiler operate safely. The research includes the working principle,process and the comparison of like products. The research is on the leak tight structure andrelevant structure material used in power plant valve based on the condition of hardfacing andthe characteristic of structure, moreover, putting emphasis on various material used foradvanced leak tight structure, material acceptance criteria, and the relevant heat processapplied for obtaining the satisfied mechanical property value defined by acceptance criteria.Our company introduced the technology of "the valve used by super (altra) critical powerplant" from Toa Vavle Engineering inc., we found that the Japanese hardfacing relevantstucture--stem nut is applied austenitic globular graphite cast iron instead of conventionalaluminum bronze in china. Therefore, the research is on friction factor determination principleand method, and factual measurement value of austenitic globular graphite cast iron frictionfactor.