GFD metal O-rings have been developed as a secure sealing of gases or liquids. They even can be used in case of extreme conditions. These static and metallic sealing elements can be applied in ranges of ultrahigh vacuum and up to a pressure of 6800 bar. They are suitable in case of continuous temperatures from 269 degrees centigrade below zero up to 980 degrees centigrade above zero and resistant to radioactive radiation, chlorides, corrosion and other aggressive influences. They neither age in use or during storage.


Construction - materials - coating - dimensions

GFD metal-O rings are produced of metal tubes or solid wire material. The material is shaped and welded to rings or other figurations. The O-ring consists of stainless steel or other alloys and can be electroplated with silver, cooper, indium, nickel, gold, lead or other metals or can be coated with Teflon*). The flowing of the coating material improves the sealing especially under high pressure and / or vacuum. GFD offers a variety of heat treatments according to material or customer's specifications, as the resistance to extension and the spring deflection are partially determined by the thermal subsequent treatment. Hollow or solid wire rings can be produced in sizes from 6.4 mm up to 2500 mm outside diameter.


Application and function

The metal O-ring is axially pressed between parallel surfaces, which are arranged at right angles to the flow or to the vessel, as typical application. The sealing is usually placed in an open or closed groove, but can also be installed in a holding device. The working of a groove can be omitted for this reason. The tubing of the seal buckles slightly upon pressing to a predetermined and fixed height. As a result originate two virtual contact widths on the sealing surface and a maximum contact potential between sealing and jointing face. A spring-back effect is obtained, which pursues a positive force, due to the closing of two flanges and the resultant pressing of the O-ring. With the self-energizing performance of metal O-rings, the system pressure increases the sealing force upon the flange facing.



With conventional flanged joints many technical data, from which only very few are precisely available during the design state, have to be known for the calculation. Also the values for the rigidity of the flange, the screws etc. have to be available. The consequence are extensive calculations with imprecise or assumed values and the involved disadvantages. There is always a defined initial tension, no setting and smaller flange and screw dimensions with the GFD metal O-rings or lip seals. The proof has not to be furnished with complicated and difficult calculations about unknown quantities but simply by adding the forces of pressure to the operating pressures.


© 2020 GFD - Gesellschaft für Dichtungstechnik mbH
Hofwiesenstraße 7, D-74336 Brackenheim, phone (+49 7135) 95 11-0, fax (+49 7135) 95 11-11 - Imprint | Privacy policy