Highly Reliable Fire Resistant Insulating Flange Seals
We can only add that the more severe the conditions in which the seal operates, the greater the likelihood of damage and the more serious the consequences.
And in this context, of particular interest, in our opinion, is the fire-resistant combined disk seal GERDA-VCFS “Pikotek”, which provides reliable tightness and electrical insulation of flanges at high pressure, high temperature and aggressive environments, maintaining functionality even under conditions of direct exposure to flame.
The GERDA-VCFS “Pikotek” sealing technology is based on the standard VCS design, which was originally developed by the American company Pikotek to provide reliable sealing and electrical insulation of critical connections operating in the most severe conditions (VCS = Very Critical Service), especially where used RTJ flanges with phenol-formaldehyde resin O-rings, which often failed.
The VCFS version (FS = Fire Safe) was created by adding a secondary fire-resistant sealing element to the basic design, which ensures a leak-tight connection at temperatures up to 815°C.
The basis of the VCS seal design (Fig. 1) is a support disk made of stainless steel, on which an insulating glass epoxy coating is applied, which has high mechanical and electrical strength, low water absorption and an operating temperature of up to +200°C.
A concentric groove is machined on each side of the disk, into which a spring-loaded dovetail-shaped Teflon sealing element is installed, which creates an impermeable barrier to liquid and gas throughout the thickness of the coating and provides a “self-sealing” effect, when the tightness of the connection increases with increasing internal pressure in the docking unit. Such a highly reliable sealing system allows the use of VCS at operating pressures up to 70 MPa.
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Fig. 1 Basic VCS seal design |