Until the early 1960’s sewerage pipelines were predominantly jointed using tarred yarn with a cement mortar fillet. To be successful, these joints greatly depended on the skill and diligence of the installer and when completed were totally rigid with no flexibility to allow for subsequent ground movement.
With the late 1960’s came the change from rigid joints to ‘flexible’, designed to accommodate straight draw, angular deflection and transverse shear load without leakage or failure of the joint.
Examples of this philosophy are Integrated Seal Joints
The Trelleborg Pipe Seals integrated sealing system was the first and original sealing system whereby the rubber seal is cast into the socket during pipe manufacture. Advantages to the pipe layer include:
This philosophy also applies to Manhole joints where applying lubricant to the underside of a suspended load is an unnecessary risk.
Advanced seals are available incorporating an enclosed skin or mantle integrated onto the main sealing body, internally lubricated with silicone grease.
This makes centring the joint easier, removes the need for external lubrication, and reduces jointing force thus allowing assembly to be made under the self weight of the manhole elements.Our most advanced system, the Forsheda 171, includes an integrated ‘Load Distribution’ elements which prevent concrete to concrete point loading through the manhole section joints and removing the risk of structural failure.
Die F165 ist eine einteilige integrierte Dichtung für Niedrigdruck-Betonrohre und Schächte. Sie wird während der Rohrherstellung in den Rohrstutzen eingebracht. Die Dichtung kann ebenfalls für Betonrohranschlüsse bei Schächten verwendet werden.