Plastic Retainer IPS
Forsheda 578 is a rubber seal for plastic pressure pipes and waste water conduit in ground.
The F-578 seal meets the requirements of all relevant current European standards as well as the American Standard ASTM D 2241, for both pressure and vacuum, deflection and shear load. Test reports are available from Trelleborg Pipe Seals Lelystad bv on request.
Hardness 50±5 IRHD or 60±5 shore A
Approved in accordance with EN 681-1 and meets the requirement of ASTM F-477
Approved for contact with cold potable water
Available in oil resistant material
Detailed material specification is available from
Trelleborg Pipe Seals Lelystad bv on request.
Seal Design and Function
Forsheda 578 locked in seal is a combined lip and
compression seal which is locked inside the pipe socket. Making the seal an integral part of the pipe eliminates many of the disadvantages of separate sealing rings. It makes a perfect seal in high or low pressure pipes. The seal is positioned in the socket by the pipe manufacturer. A ”retaining ring” of polypropylene holds the sealing ring securely in postion during transport and pipe assembly. The ”front lip” prevents dirt on the spigot from entering the joint. The ”main lip” comprises a combined lip and compression section. The ”rear lip” locates the seal in the socket groove and absorbs any permissible variations in the groove.
When the pipes are pushed together the rubber in the F-578 seal is compressed. Compression gives rise to a sealing pressure which acts on the socket and spigot as shown by zones. When the pressure in a pipe varies widely, the seal will inevitably move slightly. Many seal profiles are then unable to prevent solid particles from finding their way into the joint. Owing to its exclusive lip design this problem does not arise with the F-578 seal.