HDPE Electrofusion Machines
Electrofusion is a simple method of joining PE pipes by incorporating an electrical heating coil which melts the plastic of both the fitting and the pipe, causing them to fuse together.
The characteristics of the fitting to be welded, such as the fusion time, are registered via a barcode on the fitting. An electrofusion control unit (ECU) supplies the electrical energy necessary to heat the coil. When the coil is energized, the material adjacent to it melts and forms an expanding pool which comes into contact with the surface of the pipe. The continued introduction of heat energy causes the pipe surface to melt and a mixing of pipe melt and fitting melt takes place; this is vital to produce a good weld. Following the termination of the heat cycle, the fitting and the pipe are left to cool and the melted material solidifies to form a sound joint.
Hot and cold zones, sometimes called melt and freeze zones, are formed after energizing the coil. The length of these zones is particularly important. Each zone ensures that fusion is controlled to a precise length of the socket of the fitting and that the melt pressure is also controlled throughout the entire surface of the socket ensures uniform heat distribution.
The basic fusion parameters: temperature, pressure and time, are controlled by the ECU which is programmed to establish these parameters from the barcode read from the fitting itself. The ECU also provides a permanent record of the procedure followed.