Weld Ring Gaskets
We recommend weld ring gaskets for use in any place where a welded seal is necessary, due either to the danger of the medium or the danger presented by a loss of functionality, but where the connection also needs to be detachable to a certain degree.
These gaskets are therefore described as being semi-detachable, as the welded sealing joint needs to be undone as well as the flange bolts.
Weld ring gaskets are generally made of the same or a related material as the pipe or flange and are only used in pairs. The choice between the various profiles depends on the operating conditions of the weld ring gasket.
The “attachment seam” is the connection of a welded half with the flange. The “attachment seam” can be located internally or externally. The “seal seam” is always the welding of both weld rings with one another. The suitability of the materials for welding (gasket to flange), the ability to weld (proper fitting) and the security of the welding (expert layout and specifications) should be assessed and tested with regard to the local operating conditions by an expert welding engineer.
The “attachment seams” and “seal seam” should be arranged so that they can withstand all load conditions. Weld rings with hollow lips optimise the stress ratio in the seal seam. Weld rings with hollow lips are recommended for use when connecting components with different heat exchange properties. The advantage of weld ring gaskets lies in their greater motion absorption.
They are predominantly used with heat exchangers with differing radial strain properties, e.g. as gaskets between channel flanges and tube plates. With the A24 gasket the weld seams are not accessible from the outside. However in many cases this is an advantage, particularly where creep corrosion is feared.