Belling Machine Forms 'Rieber' Socket in PVC-O Pipe
Italy’s SICA has developed an innovative Rieber belling process specific for PVC-O pipes. At the same operating pressure, these pipes require a wall thickness of about 35-40% less than those in conventional PVC pipe and allow the construction of water supply pipes up to 25 bar of operating pressure.
Italy’s SICA (U.S. sales office Norcross, Ga.) has developed an innovative Rieber belling process specific for PVC-O pipes (oriented PVC pipes). At the same operating pressure, these pipes require a wall thickness of about 35-40% less than those in conventional PVC pipe and allow the construction of water supply pipes up to 25 bar of operating pressure. Because of these and other advantages, PVC-O piping systems are becoming increasingly popular.
Like conventional PVC pipes, the PVC-O pipes are joined in a socket. The socket, including the gasket seat, is made in an extrusion line with a special belling machine.
In standard PVC pipes, “Anger” type socket are used, i.e. with removable and replaceable gaskets, as well as “Rieber” type sockets that have a gasket already integrated in the belling phase and not removable during the assembly of the pipeline. The Rieber system is popular because during installation the possibility of accidental displacement of the gasket is reduced and the risks of external water dispersion are lower.
The realization of the socket in PVC-O pipe requires different procedures than the conventional ones for conventional PVC pipes. Up to now, these specific procedures have proved to be industrially applicable only for forming Anger-type sockets. The absence of the Rieber socket joint in the PVC-O piping sector has excluded its application where the Rieber socket is considered decisive for the operating conditions for laying the pipelines.
Photo: SICA
The innovative and exclusive SICA Rieber belling process for PVC-O pipes changes the scenario and makes the Rieber system possible on belling machines used in bioriented pipe production lines. In fact, the belling machines are able to process both pipes produced and oriented continuously in the extrusion line, but also pipes oriented off-line in a tank. The Rieber SICA belling system is functional in PVC-O pipes that comply with all the following technical standards:
- European EN 17176
- American ANSI / AWWA C909 and ASTM F1483
- Australian AS / NZS 4441
- Canadian CAN / CSA-B137
- International ISO 16422
The SICA machines that make the Rieber belling process possible are available in three models based on the dimensions range of the machinable pipe.
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