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Metal to rubber bonded washers, also known as Dowty seals
Designed for use as connector seals in hydraulic equipment, bonded seals (commonly known as Dowty Seals or Dowty Washers) are used across a broad range of applications including fluid systems in power generation, aviation and defence and general industrial applications.
A bonded seal or washer consists of a metal outer ring with an inner ring of rubber, which acts as a gasket and provides a sealing function.
Normally presented in a typical circular format, the same basic concept can also be used to produce customised shapes for specific applications. The rubber element can also be designed to make the washer ‘self-centring’, which simplifies component assembly, makes fitting easier, particularly in difficult locations where access or vision is limited, and ensures correct alignment, preventing the sealing element from being trapped or damaged.
Typically used to provide an effective seal for the connection of bolts and threaded screws on fuel, hydraulic and pneumatic pipelines, bonded washers consist of a metal washer with a rubber sealing element bonded to its inner diameter. The metal washer provides structural support and prevents over-compression of the rubber sealing element, while the rubber creates a tight seal against the mating surfaces absorbing vibrations and reducing the chances of loosening or failure due to dynamic movements.
Bonded washers can be used to replace unsuitable metallic or fibre washers in high-pressure applications on hydraulic and pneumatic pipework connections, easily coping with extremes of pressure, temperature and aggressive media. Their simplicity of design and the fact that their material makeup can be tailored to the application, means bonded seals are trusted to maintain system integrity, reducing the risk of costly leaks and downtime, and enhancing the overall performance and reliability of critical systems.
Typical applications
Bonded washers are suitable for the majority of fluid transfer applications, including fuel, hydraulic, pneumatic and HVAC / cooling systems. Suitability for specific applications is dependent on the materials selected.
Materials of construction
Both the metal and rubber materials can be specified in a variety of options to match the operating conditions of the application.
The metal washer is commonly available in mild steel, stainless steel, and aluminium bronze, but can also be produced in other material grades to meet specific customer requirements.
The rubber sealing insert is available in nitrile (NBR), hydrogenated nitrile (HNBR), fluoroelastomer (FKM) and ethylene propylene diene (EPDM) elastomers. Rubbers with low compression set are preferable to provide a consistent, effective seal requiring no interim tightening even when subject to vibration or heat cycling.
Performance
Sizes
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