Modern construction is not complete without the use of polyethylene pipes. These products are manufactured under low pressure and are used in the construction of pressureless and pressure pipelines. To obtain such pipes, polyethylene is used, which has the brands PE 100 and PE 80. The material has high elasticity, so it is very easy to work with it, and laying the pipeline is carried out in a short time and with less labor. Among the advantages of using such pipes, one can distinguish a long service life, the absence of corrosion, resistance to negative factors, the possibility of trenchless laying of the pipeline, as well as a smooth surface, which ensures unhindered passage of fluid.
Among other things, polyethylene pipes are lightweight and allow you to quickly mount systems of complex configuration. The material is resistant to temperature changes, has high ductility and mechanical strength. This product can be used in regions with high seismicity, as the systems undergo ground movement.
Types of connections for polyethylene pipes
If you are thinking about how to connect HDPE pipes, you should first familiarize yourself with the methods of work. Depending on the purpose of the pipeline system, you can use one of two methods: detachable or one-piece. The first technology provides for the possibility of dismantling during operation. While one-piece connections do not provide for the possibility of subsequent disassembly. If you decide to use a detachable connection method, then you should use flanges that are made of steel. In this connection is called flanged.
Before connecting the PND pipes in one-piece method, you should get a welding machine, while the pipes will be butt welded to each other, and the master will have to use superimposed couplings. Electric heating elements are connected to the connection. Among other things, you can use a collet connection, which requires the use of compression fittings. This technology is used on pipelines of small diameter.
Why choose plug-in connection
If you are thinking about how to connect HDPE pipes, it is worth considering the methods of work. Experts have increasingly advised recently to use the split method, which has a number of advantages over the one-piece method. Firstly, the detachable connection allows saving, secondly, it is more affordable, thirdly, the master will be able to increase the speed of work. If we consider the first option, then you will not need to use special expensive equipment for welding plastic products or pay for the services of a specialist. Moreover, a detachable connection can be made even where the use of welding is not possible, this can include conditions under water. And finally, this method allows you to connect products at high speed.
Features of detachable connection
Before connecting HDPE pipes using the split method, you should choose a method that can be socket or flange. In the first case, elastic gaskets should be used, which are most often used in the arrangement of pressure-free sewage piping systems. As for the fitting, or flange connection, in these two cases, fasteners are used.
Coupling recommendations
If you have a question about how to connect HDPE pipes correctly, you should become more familiar with the features of using couplings. These parts are polyethylene elements, and extrusion technology is used in their manufacture. This method eliminates the use of welding machines and does not involve the purchase of expensive equipment. As practice shows, couplings are cheap, and their use allows you to save on construction.
Why else use couplings
Couplings are quite common when connecting polyethylene pipes for the reason that they have a long service life, which reaches several tens of years. As a result, it is possible to obtain the most reliable fastening, which is resistant to aggressive environments. The coupling has a wide area of use and can be used for arranging pipelines of almost any purpose.
Using fittings
Novice masters often wonder about how to properly connect HDPE pipes with fittings. When carrying out such work, certain rules must be followed. They provide for the need to disassemble the compression fitting by unscrewing the union nut. The pipe must be cleaned of dirt, and a chamfer must be made at its end. To do this, it is necessary to use a chamfer, but in the absence of this tool, you can use a sharp knife. If you faced the problem of how to connect pipes with PND fittings, then on the product with a marker you need to make a mark that will determine the depth of entry into the fitting. Before entering the part, the pipe must be moistened with liquid soap. Next, the introduction is carried out, and when performing this action, you will have to make an effort, since the rubber sealant creates a certain resistance. At the final stage, the fitting nut is tightened. It is important not to overdo it so that the connection is not overtightened.
Connection of a plastic pipe with a metal
If it is necessary to extend the old metal pipeline, it is often necessary to connect it to a polyethylene product. To do this, prepare two sliding keys, tow or teflon tape. You will need an adapter with one end in the form of a metal product, and the other end should be in the form of a bell for movable connection of a plastic pipe. If you were faced with the question of how to connect the HDPE pipe with a metal one, then at the first stage you need to unscrew the pipe coupling in the place where the connection is planned.
It is necessary to hold the coupling with one adjustable wrench , and the pipe with the other. If the connection cannot be unscrewed, an oil with increased penetration ability can be used. The next step is to use the tool for plastic pipes and seal the threaded connection. This will further prevent leakage. On the pipe, clockwise, make several turns of the tape, closing the thread. If you are thinking about how to connect the PND pipe to a steel pipe, then at the final stage you need to install and tighten the adapter. The connection is tightened until you feel resistance. It is not recommended to screw fittings with internal thread of polyvinyl chloride on the metal, as these two materials have different thermal expansion.
Connection of a polyethylene pipe with a tap
The most popular method of joining a polyethylene pipe with a ball valve is butt welding. It should be performed using a special installation, in which both edges of the welded workpieces are fastened. The surface is cleaned of dirt and degreased. The heating element will increase the temperature of the edge of the polyethylene pipe to a viscous state, while the mechanism of the apparatus will help to strengthen the elements to each other. After the PND pipe was connected to the crane, it was necessary to leave the elements to cool completely. If the work is done correctly, the welded joint will look like an even seam of the same height along the entire circumference.