Trelleborg’s pipe seals operation has developed a new integrated concrete pipe seal design – the Forsheda 165 - which reduces the risk of concrete ingress during pipe manufacturing and improves sealing performance.
Using a co-extrusion method, Trelleborg’s new seal features a slurry lip made of soft rubber – 50 International Rubber Hardness Degrees (IRHD) - for improved flexibility. Similarly, the enhanced profile of the seal ensures a more secure fit against the pallet, removing the risk of leaking concrete and unnecessary pallet cleaning. The forming parts of the seal are made from hard 70 IRHD rubber to increase stability and grip.
Julian West, Product Manager at Trelleborg’s pipe seals operation, says: “The correct design of an integrated seal within a concrete pipe is vital for its installation into the pipe and its placement into the ground too. If the seal is not designed to the right rubber stiffness, it can compress under pressure when being fixed onto the pallet. Similarly, if it is not stable, the vibration that is applied to the concrete as the mold is filled can cause the seal to be displaced, or even lift off the pallet.
“Once the seal is in place within the pipe, it cannot easily be moved or replaced. It is therefore vital that the seal performs exactly as required, first time, to avoid unnecessary loss of time and money associated with pipe scrappage.”
The Forsheda F165 seal provides benefits for pipe manufacturers, installers and specifiers. It is easier to stretch and accurately position onto the pallet, reducing the risk of compression or bouncing. Similarly, the rubber’s optimized stability during concrete vibration ensures more accurate socket dimensions and lower scrap rates.
The optimum jointing force of the F165 seal makes it ideal for mechanized pipe laying. This improves health and safety onsite as fewer installers are required to be in the trench during installation. In addition, the seal offers near zero push-back and excellent jointing even at low temperatures.
West continues: “We are aware of the fact that the performance of the seal can also be affected during packaging and delivery. To prevent the seal warping or misshaping, we only pack them once they have reached a suitable temperature. We also limit the number of seals per box to ensure they arrive ready for pipe production in the same condition as they left the factory.”
Trelleborg’s new F165 seal complies with EN 1916, EN 681-1 and German legislation, QR4060. Made from EPDM rubber, as opposed to SBR rubber, Trelleborg’s F165 integrated seal offers much better long term longevity.