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PP compression accessories and related methods PP compr […]

PP compression accessories and related methods

PP compression joints are used to make permanent tight connections between tubes. The fitting has at least one end having a hook-shaped cross-section and a beaded configuration that retains the O-ring and can be compressed with a tube. An adjacent cylindrical portion extending in the longitudinal direction is provided at the end with a bead-shaped recess serving as a stopper for the insertable flat tube.
In order to form a compressible fitting that can be economically manufactured and still provides a quick connect technique, the invention proposes that the region characterizing the type of fitting is designed as a cast or molded matrix made of metal or non-metallic material, which is connected by a A standardized connector made of sheet metal, wherein the connector has a beaded end that holds an O-ring and an adjacent cylindrical region that is provided with a beaded recess that serves as a stop for the unit. A tube that can be inserted.

Devices for compression fittings made of carbon steel or high alloy steel for internal mounting are known in the prior art. A booklet published by Mannesmann Edelstahlrohr GmbH shows such a booklet. At the heart of the system is a deformable compression fitting made of a length of tubing, depending on whether it is designed as an elbow, tee or reducer, with at least one hook and beaded end and retaining a washer. Adjacent to the end is a cylindrical region extending in the longitudinal direction. A beaded recess is attached to the end of the extended portion of the cylindrical region, the recess extending radially inwardly and serving as a stop for the insertable flat tube. By means of an activation device connected to a positioning device having an articulating jaw.

In addition, the same compression process is employed in the cylindrical region of the fitting, and in the immediate vicinity of the beaded end, the beaded recess is pressed and the tube inserted underneath is compressed. The elastically deformable gasket in the attachment system performs a sealing function while the compressed beaded recess absorbs longitudinal forces generated by internal pressure.

A disadvantage of this system is that due to the high demands on surface quality and dimensional tolerances, the compression fitting is made from a part of a specially made tube, using several deformation and conversion steps. The basic or initial tube is typically a seamless or longitudinally welded tube that is subjected to a heat treatment after cold deformation. This specially manufactured tube requires precision tolerances and high surface quality. To make a compression fitting from the tube, the original tube is cut into multiple sections and the desired final cross-sectional shape is created by performing several transformation steps (eg, tapering, crimping, and chasing). Since basic products or raw materials are already relatively expensive,

The proposed PP compression joint is preferably suitable for connecting commercial pipes, rigid pipes, metal pipes and line pipes, with a size range of 10 to 100 mm and internal pressures up to 100 bar, depending on the nominal width. Therefore, the connection system can be used. Handle larger nominal widths.

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