Bonded Seal (Dowty Washer)

A bonded seal, also known as a Dowty washer, is a type of sealing washer used to prevent fluid leakage in high-pressure systems. It consists of a metal ring (usually steel or stainless steel) with a vulcanized rubber insert (typically nitrile, viton, or silicone) bonded to its inner diameter. When compressed between two surfaces, the rubber forms a tight seal while the metal provides strength and resistance to deformation. Bonded seals are commonly used in hydraulic and pneumatic systems, especially where threaded bolts or fittings are involved.