Dowty Washers?

AOK Valve Stem Seals Ltd. supplies various bonded seals (sealing washers) and which are also called “dowty washers”. With years of experiences and advanced technology, AOK is excellent in producing the high-quality bonded seal (sealing washer) with ISO 9001 and TS16949 qualifications. We focus on creating value for customers by providing outstanding technical and manufacturing services.


Established in 1995, AOK Valve Stem Seals Ltd. is a manufacturer specializing in producing valve stem seals, boned seals (sealing washers), large size O-rings, large size oil seal, bushings and precise customized rubber molded products. Maintaining excellent quality and customer satisfaction is our first priority.