Integrated seals for concrete pipe and manhole systems have been around for many years. Originally developed and introduced by Forsheda AB in the 1970’s the concept of casting the rubber seal into the pipe or manhole socket during manufacture was a significant step in reducing the possibilities for error during installation in the trench.
Mechanically securing the rubber seal in the pipe socket at the point of manufacture in the controlled environment of the concrete factory ensures seals cannot be lost during stocking and transportation, nor damaged or displaced during jointing and installation of the pipe line.
The integrated joint is now the system of choice for the majority of European manufacturers and is fast gaining popularity in many other countries throughout the world.
The Forsheda 165 is the latest evolution in integrated sealing systems and is made from two grades of EPDM rubber. The slurry lips and sealing element, essentially the part that will be joined with another pipe, is made of a soft rubber, whilst the ‘shell’ is made from harder rubber to give the seal increased stiffness to simplify loading onto the pipe pallet and improved stability during the pipe manufacture process.
As experienced designers and manufacturers of integrated system, Trelleborg’s engineers know only too well that the difference between a successful or problematic integrated jointing system is in the details of both design and production.
For example the function of the ‘slurry lips’ which seal against the pipe pallet to prevent concrete ingress into the sealing area is crucial to ensure clean sockets of the correct tolerance. Furthermore no slurry leakage means the pipe pallet remains cleaner for longer thus reducing the need for costly maintenance and cleaning.
This may sound like a simple component of the design but many seals available in the market suffer from deformation of the upper slurry lip causing concrete leakage, and often leads to seal displacement.
Seal before mounting on the pallet.
To the left is a typical seal showing deformation ‘waves’ to the upper section and slurry lip. Even when stretched onto the steel pipe pallet this deformation remains, leading to concrete leakage past the lip and into the sealing area.
The Forsheda F165 above, is expertly designed to prevent deformation during production, transportation and storage allowing a perfect fit against the steel pallet.
We, at Trelleborg Pipe Seals pride ourselves with paying attention to details. Details that enhance and improve our products and those of our customers.
Probably, the best performing integrated concrete pipe sealing system available