... is the back liner which was made of high-elasticity rubber, the liner ring disc adopts the double spherical surface sealing ... metal seated) gate valves, globe valves,check valves,butterfly valves, ball valves, plug valves strainers, etc.in accordance with the latest ... WALWORTH, CRANE, and OARI etc.Our company have be awarded ISO9001:2000 Quality Certification in May.2007.At present,most of our ...