Polyethylene low pressure(HDPE) is a solid polymeric material obtained through the polymerization of ethylene. HDPE has the following physical and chemical properties:
The above properties determine the popularity of the use of low-pressure polyethylene in various industries. Primary processing of HDPE is carried out in four available ways:
The properties and affordable market price of HDPE determined the benefits of making plumbing and gas pipes... Installation of low-pressure polyethylene pipes (diameter from 10 to 1600 mm) is carried out in three available ways:
The predominant method of connecting HDPE pipes is compression. It differs in:
As noted above, the compression installation of pipes is impossible without the presence of special connecting parts - fittings. Depending on the nature of the connection, HDPE compression fittings can have the following types:
All of the above types of compression fittings have a similar design - a polyethylene body with an external thread and a retainer, an O-ring and a ferrule, a sleeve, a nut-cap.
You can buy HDPE pipes and fittings for hot and cold water supply, heating and sewerage systems in Moscow at a bargain price in the Terem online store. The company's catalog contains a wide range of products of the European (REHAU, TIEMME, STP) and Russian (CYKLON, RUVINIL, Dzhileks) manufacturers with detailed description technical characteristics, advantages, areas of application of the product, etc. All products of the online store comply with the ISO 9001 quality standard, are reliable and durable.
"Terem" - reliability, quality, stability.
Connecting elements can be classified according to a number of characteristics:
1. Purpose of application
2. Installation method:
3. Hardness:
4. Connectivity:
Our catalog offers big choice connecting elements for HDPE pipes. Here you will find compression, cast, electrofusion fittings. We supply products directly from the manufacturer, which allows us to form attractive prices without additional markups and overpayments.
Pickup points in the cities of Moscow, Klimovsk and Novomoskovsk will allow you to pick up the goods at a convenient place. You can also order delivery in Moscow and the Moscow region.
Due to the wide popularity of various types of polyethylene pipes, the demand for connecting elements called fittings is increasing. HDPE pipe fittings allow for easy installation and in a short time. At the moment, many different compounds are produced by enterprises. Fittings for HDPE pipes are made of various types of polyethylene, copper or brass.
Fittings for HDPE pipes are used:
The joints of PE pipes must be:
Professional pipeline installers distinguish between HDPE pipe fittings by:
There is another classification of connecting elements:
Let us examine in more detail the first classification of fittings.
Depending on the chosen method of installing the pipeline, there are:
Welded fittings can be manufactured in two ways:
Welded fittings are available in diameters from 63 mm to 315 mm.
This type of fittings is designed for connecting pipes by welding. The low cost of welded fittings leads to a wide range of applications. Almost all branches and plugs provided for by the pipeline design can be made with welded connecting elements.
Most often, welded fittings are used during installation gas pipelines and systems in which the temperature of the transported liquid does not exceed 40 ° C.
Electrofusion or thermistor fittings are used for the installation of a pipeline structure in hard-to-reach places, that is, where it is impossible to carry out conventional butt welding.
Equipped with heating wire located on the connecting parts. Under the influence of temperature, these spirals heat up and melt the polyethylene pipe. After cooling, a strong weld is obtained.
Compression fittings for HDPE pipes are designed to connect pipes without the use of welding. With the help of such butt elements, a detachable connection is obtained.
Fittings of this type consist of:
Produced from various materials... The diameter of the connections varies from 16 mm to 110 mm.
To correctly connect the pipes or make the necessary branches with compression fittings, you must follow the following instructions:
At correct installation compression fittings get a sufficiently strong and tight connection.
According to the degree of rigidity, fittings are distinguished:
Flexible joints are most suitable for buried pipelines, but are also more costly. Therefore, they are used only when absolutely necessary.
For the installation of the simplest piping systems, rigid fittings are often used.
When installing the pipeline, both detachable and one-piece connections may be required. This is due to the location of the pipe joint and its application. For example, HDPE pipes for water supply: fittings at the first stage of installation are used to connect the pipeline with pumping station... At some point in time, it may be necessary to replace the pump and the detachable connection will simplify the necessary work as much as possible.
In most cases, installation is carried out with the compression fittings described above. But there are other ways to arrange such a junction:
For detachable connections, brass fittings for HDPE pipes can be used.
One-piece joints are most often used to connect structures that are underground or in concrete, since this type is considered the most reliable. Welding of pipes can be carried out in the following ways:
Cast and electrofusion fittings are used to equip the permanent connection.
All fittings differ in their design features and, accordingly, the scope. Depending on this, fittings can be divided into:
A certain type of fitting is intended for the installation of a certain pipeline structure.
Fittings are available to facilitate assembly of polyethylene pipes. A correctly selected set of connecting elements will maximize the time required for the installation of the piping system and greatly facilitate the work of connecting the pipes.
Currently, when laying communication lines for various purposes often used low pressure polyethylene pipes (HDPE). Their installation is carried out using special fittings, which include ball valves. Next, we will consider what these products are, what they are and what their features are.
Polyethylene ball valve 25 - 25 mm
Plastic ball valves for HDPE pipes are shut-off valves designed to completely shut off the flow of liquid transported through the pipeline. They are called spherical for the reason that the locking mechanism is made in the form of a ball with a through hole.
The ball can be rotated 90 degrees in the housing to open or close the passage. The position of the locking mechanism is controlled by a lever. In large-diameter cranes (150 mm and more), the locking mechanism is controlled by an electric drive, pneumatic or hydraulic drive.
The body of these devices is made of HDPE, i.e. the same material as the pipeline itself. The locking mechanism is most often made by manufacturers from polypropylene or another type of plastic.
The shutoff valves under consideration have many positive qualities, among which are:
For objectivity, we also present some of the disadvantages of the devices under consideration:
Note!
Before using a plastic ball valve for HDPE pipes, you must make sure that its characteristics correspond to the conditions in which it will be used.
In addition to the fact that the devices in question differ in diameter, they can also be designed to different ways installation:
Below we will take a closer look at the features of each type of device.
These devices are used for pipelines of small diameter - 20 mm - 110 mm. Their main feature is the ease of installation, which can be done by hand without the use of special equipment, and without having the skills of such work.
Note!
For high-quality installation of the crane using a collet method, it is necessary strictly perpendicular to their axis and chamfering a few millimeters, as shown in the diagram above.
As a rule, these valves are used in domestic water supply systems. Below are the main characteristics of these devices:
Specifications may vary slightly depending on the device model. However, in general they correspond to the data from the table.
It must be said that compression valves can have either the same dimensions of the inlet and outlet pipe, for example, 32 - 32 mm, or different, i.e. can serve as adapters between pipes of different diameters.
In the photo - a flanged polyethylene valve
Flanged HDPE ball valves are used for large-diameter pipelines (up to 315 mm). They are connected to the pipeline using a bolt method using flanges. As a collet, this connection is collapsible.
Unlike devices of the previous type, flanged shut-off valves are able to withstand higher pressures. Often, these valves are used in the chemical industry, as they are resistant to acids and alkalis, and are not subject to corrosion.
This connection method is used in cases where it is necessary to ensure tightness. Installation instructions in this case are more complicated.
Welding can be done in two ways:
Here are, perhaps, all types of polyethylene ball valves.
Polyethylene ball valves are reliable shut-off valves used for various types of HDPE pipelines. As we found out, depending on the purpose of the line and its diameter, they can be mounted in different ways.
From the video in this article, you can pick up some Additional information on this topic.
Fittings for HDPE pipes (low pressure polyethylene) are in demand in residential and private construction, they are used as connecting fittings for cold water supply, sewerage systems and gas pipelines. As a rule, they can withstand a working flow pressure of up to 10 atm for gas or 16 atm if water is transported.
Fittings provide reliable and quality installation NPD pipes, which does not take much time and does not require much effort, for example, compression couplings can be installed using only a wrench.
The sale of these products is established in almost any city, so there will be no problems with the acquisition. The cost of fittings is influenced by the type, size, and different kinds technical parameters.
Fittings used in the installation of pipes made of HDPE are usually classified according to the type of connection; the following options are currently practiced:
Accordingly, each method requires the use of its own type of pipe fittings. Let's consider each of them in detail.
Video: HDPE compression fittings, couplings, bends
For this method, connecting fittings are not needed, since the pipes are welded directly end-to-end. Welding allows you to provide almost any design solution.
The figure shows all the stages of this process:
The cooled connection is immediately ready for use.
Main advantages:
Flaws:
This technology will help in cases where it is impossible to apply conventional welding, for example, when welding equipment cannot be installed at the joint. Connecting fittings for HDPE pipes are electrofusion fittings (couplings) on which an open electric heating coil is installed.
To connect pipes with this method, you need a welding machine equipped with a barcode scanner, a photo of such a device is shown in the figure below.
The connection process is performed according to the following algorithm:
This method is good because it does not require special skills, it is completely easy to learn it. But there is a significant drawback of this technology for connecting HDPE pipes - high prices for welding equipment and fittings.
Threaded (collet) pipe joints made of HDPE are more popular than other methods, this is due to the fact that there is no need to resort to expensive specialized equipment.
Everything assembly work can be made with an ordinary tool, in rare exceptions a wrench may be needed (when crimping nuts with a diameter of 63 to 110 mm).
Note that, in addition to connecting pipe fittings for crimp connections, a shut-off valve is also produced, that is, on which taps are installed, which significantly expands the scope of its application when conducting a water supply system.
Using compression fittings for connecting pipes made of HDPE material with a diameter of 20, 32, 50 mm, etc., you can independently assemble a reliable and durable water supply system for a house or apartment. This is easy to do if you adhere to the following recommendations:
To connect pipes made of HDPE material together by a crimp method, you can also use brass fittings, which, although they are much more expensive, have many advantages, namely:
The only drawback, as mentioned above, is the high cost, but if you can afford not to save on quality, then we recommend using this particular type of pipe fittings.
It is impossible to do without this type of pipe fittings if it is necessary to ensure a transition from pipes made of HDPE to metal pipes, for example, for connecting to a riser.
We give the price level in various cities of Russia for the most common type of connecting elements for HDPE pipes, namely, compression fittings, this information can be useful if you are going to buy them, but there is no time to do a comparative analysis.
The average price level for fittings for HDPE pipes in different regions of Russia is approximately the same, the cost of the device in Nizhny Novgorod, Samara, Chelyabinsk and Moscow is approximately at the same level. The survey was carried out for retail prices, therefore, the wholesale price will be lower.
