Bonded Seals, also known as Dowty Seals, Dowty Bonded Washers, Dyna Seals, Multiseals or Usit Rings, are a modification of the traditional sealing washers, originally disigned to replace copper-type washers in high pressure environments and in those hydraulic and pneumatic systems where copper washers were unsuitable. Dowty Seals have a rectangular section metal washer and an elastomeric trapezoidal lip bonded to the inside diameter, the metal washer has the double function of preventing over-compression and limiting the deformation of the elastomeric lip. Both the metal washer and the elastomeric lip are available in a range of materials to suit a variety of requirements, Dowty seals are commonly supplied in mild steel zinc plated or stainless steel, while the elastomeric sealing lip can be supplied either in NBR, HNBR, EPDM or Viton. Alternatively, Dowty seals can be supplied as self-centering bonded seals with an extra sealing lip on the ID of the elastomeric ring to eliminate seal offset and simplify installation. Mainly suitable for fittings, screw connections, hose couplings and flange joints, Dowty seals are readily available from stock in a range of metric and imperial dimensions (from 1/8 inch to 3 inches).