What are the diameters of HDPE pipes, types, characteristics. Polyethylene pipes HDPE (PE) Polyethylene pipes for cold water supply

HDPE water pipes for cold water supply are used both in small summer cottages and in huge cottages. Due to its characteristics, this type of pipe is really very popular. To understand the features of HDPE pipes, you first need to determine what it is.

HDPE pipes are pipes that are made from low-density polyethylene; enterprises use the continuous screw extrusion method. Thanks to the use of this method, the pipes have special properties that are the best suited for transporting gas, industrial and even drinking water.

Polyethylene pipes are used in the repair and renovation of water supply systems, for the arrangement of swimming pools, underground wells and automatic watering systems for plants and lawns. Also, polyethylene pipes are used to supply raw materials, which are used as fuel.

Varieties of polyethylene pipes

All polyethylene pipes are divided into several subspecies:

• LDPE are produced at high pressure;
• HDPE is produced at low pressure. This type is used mainly for the arrangement of sewer systems;
• Pressure pipes made of polyethylene. They are popular in the construction of plumbing systems. PE-80 polymer is used for production;

• Corrugated polyethylene pipes. For this type, polymers PE 80 and PE 63 are mainly used, because these materials are resistant to aggressive environments. Corrugated pipes are most often used for sewerage.

It is necessary to familiarize yourself with all the features of different types of polyethylene pipes. LDPE pipes are light in design, which greatly simplifies transportation and installation. Also, this material does an excellent job of working in an aggressive environment, which is why it is most often used for internal sewerage systems. The connection of LDPE pipes is quite simple, and at the same time the joints are very strong.

HDPE pipes are considered completely safe, durable, and they will last a long time. It is thanks to these properties that this type of pipe has become popular among users. HDPE is resistant to aggressive substances. Often people use HDPE pipes for arranging water pipes, and the material can perform the function of transporting both cold and hot water.

Polyethylene pressure pipes are usually black with blue stripes on the surface. It is necessary to use this type at low temperatures, then the service life of the product will be at least 50 years.

Corrugated polyethylene pipes differ from all others in that they are made up of two layers. The upper part of the product consists of a wave-like sheet material, which increases the strength of the pipes. The inside is made smooth, so the liquid passes without any interference, and the pipeline does not clog.

There are also non-pressure HDPE pipes, but their scope is quite narrow. The fact is that recycled polyethylene materials are used for the production of non-pressure pipes. They are flexible enough and will last a long time, but are used only to protect underground cables.

The main characteristics of a water pipe made of polyethylene

This type of pipe is supplied in large coils of 100 and 200 meters, and in some cases in small lengths of 12 meters. Given the important role of pipes (transportation of water), they must meet the following requirements:

• Surfaces, both outside and inside, must be smooth and even;
• Only small longitudinal stripes or waves are allowed, which do not go beyond the permissible limits;
• Along the entire perimeter of the pipes, the presence of cracks, shells and other damage is unacceptable;
• By standards, such pipes are painted black, and there are also blue longitudinal stripes on the surface (there must be at least 3 of them).

Polyethylene pipes for transporting water are classified according to three main characteristics: material (PE 80 or PE 100), diameter (D) and internal pressure resistance (SDR).

Pipes based on PE 80 are used for arranging sewer and water supply systems. It should be borne in mind that if pipes are to be used to supply drinking water, then they must be made of polyethylene, which is allowed to be used for these purposes. But for the supply of technical water, you can purchase PE 80 pipes even from recycled materials.

To ensure the supply of cold water from the main pipeline, PE 100 models are most often used.

Advantages of polyethylene pipes

HDPE pipes for plumbing today are used even more often than metal, cast iron or concrete. And this is not strange, because polyethylene has many positive aspects:

• Long service life. HDPE pipes, unlike steel or any other, will last about 50 years, and even more;
• They are not afraid of rust. In this area, the pipe will have to constantly come into contact with water, and possibly even with aggressive substances, but this will not cause corrosion, as on metal pipes;
• Ease of construction. Compared to metal, and even more so concrete or cast iron materials, HDPE will be several times lighter.

  This will facilitate the transportation and installation of the pipeline;

• HDPE pipes of different diameters are presented on the market, they are supplied in special bays of several tens or even hundreds of meters. This greatly reduces the amount of consumables and makes installation faster;
• Low cost for butt welding. This process takes less time and is much easier than when welding metal structures;
• Application of thermistor fittings. They are used to connect HDPE pipes, thereby simplifying welding;
• For such a simple welding, craftsmen do not need to prepare for a long time, everything goes quickly and efficiently;

• Pipes do not need insulation, electrodes, so there is no need to spend money on a polyethylene joint;
• If necessary, the pipes can be dismantled and then reinstalled;
• Such material is easily disposed of and recycled;
• You can do the installation by pulling;
• Good indicator of flexibility;
• HDPE pipes easily cope with soil loads;
• They can even withstand earthquakes;
• The inner part of the pipe is quite smooth, which allows the use of pipes of small diameter, while the hydraulic properties do not decrease;
• HDPE has a low modulus of elasticity. Simply put, with the use of such pipes, the risk of water hammer is minimized;
• If liquid freezes inside the pipeline, the material will not be affected;
• Polyethylene pipes are completely safe, therefore they are used even for transporting drinking water;

• Maintenance is unpretentious, and if necessary, the pipes are easy to repair or replace.

As can be seen from the characteristics of polyethylene pipes, they are economical, easy to repair, strong enough, withstand heavy loads and will last for several decades. That is why the masters advise using this type of pipe for arranging a cold water supply system. Polyethylene pipes are more efficient than concrete, metal or cast iron pipes.

Installation with fixed connections

This type of connection of pipeline elements is used in cases where operation is expected at a high pressure indicator.

HDPE pipe connections for water supply can be of two types:

• Butt-welding with the use of a welding device for polyethylene pipes;
• Electrofusion.

It should be borne in mind that butt welding is a rather complicated process that requires certain skills and special equipment. To do this, it is better to invite a team of specialists. A high-quality connection is ensured by one seam, which is equivalent in strength to a steel pipe.

Despite all the complexity, this type of welding is very popular, because it does not require the use of additional parts. Butt jointing using a heated device allows you to connect not only pipe elements, but also shaped parts.

Electrofusion coupling is used for electrofusion connection. In this way, it is advised to connect pipes, the operation of which will take place at a pressure of up to 16 atmospheres. Also, this welding method is considered more expensive than butt welding. An electrofusion joint is used during installation, which is carried out in cramped conditions where it is not possible to install a large welding machine. The most popular are simple electric couplings, they are designed to fasten polyethylene pipes into a straight structure.

But there are also saddles and electrofusion tees on the market. Connections of this type are mainly used for pipes with a small diameter, which are sold in coils of several hundred meters.

Installation of polyethylene pipes using detachable connections

If we talk specifically about detachable connections, then flanged ones are most often used here. They consist of special bushings that are welded to the end and cap steel flanges.

For small pipes (less than 50 millimeters in diameter), compression fittings can be used. This type of polyethylene pipe connection is used in situations where flanged connections or welding are not possible or would be very costly.

There are also collet crimps, they can withstand fairly strong loads (up to 25 atm). Such high stability in this type of connection is due to the insertion of special bushing teeth into the pipe, and the use of a rubber seal ensures the tightness of the structure.

The advantage of compression fittings is that they can connect not only polyethylene pipes with the same material, but also with other types of pipes. So, a collet type of connection is used when replacing a section of an unusable metal pipe, and HDPE is not installed in its place.

If you choose the right materials and correctly equip the water supply from polyethylene pipes, then for a long time you won’t even have to think about repairs and financial costs for this. Also, over time, HDPE pipes do not lose the characteristics that they originally had during installation.

Why you should use HDPE pipes

There are many pipe options on the market that can be used for plumbing. These are metal, and concrete and even cast iron products. Nevertheless, experts advise polyethylene pipes. This is also confirmed by users who have already managed to equip the water supply system with this material. In their reviews, users note that such pipes last a very long time, and some stores even give a guarantee. Also, the advantages of HDPE pipes include their ability to work in aggressive conditions and high strength. All these characteristics allow the craftsmen to advise their customers to equip plumbing systems from polyethylene pipes.

Prices

Pipes made of polyethylene not only have good strength properties, but also are inexpensive. So, for a PE 80 pipe with a diameter of 25 mm, you will have to pay 30 rubles (price per linear meter). The diameter of the PE 80 pipe at 50 mm is estimated by the manufacturer at 105-110 rubles. If you need a pipe with a diameter of 90 mm, you will have to pay 400-420 rubles. Larger options cost more, for example, a pipe with a diameter of 110 mm will cost 610 rubles per linear meter.

Video

In order for the autonomous water supply system in the house to work "for five", it needs high-quality components, including a pipe for the water supply.

We have already written about how to independently, or what features need to be taken into account when.

The time has come to tell FORUMHOUSE readers about what you need to know about the features of HDPE pipes for plumbing in a private house.

Pipe for water supply in the house

HDPE is the most popular material for bringing cold water into the house (from a well, etc.).

And yet, novice developers have many questions in connection with its use:

• What is a HDPE pipe;
• How to choose it;
• How to distinguish a quality product from a fake;
• How durable is it for cold water supply;
• What features need to be considered during installation.

Alex286:

- It is correct to say PE (polyethylene), and not HDPE, of course, provided that the pipes are made in accordance with GOST 18599-2001 “Polyethylene pressure pipes”.

Water pipes for the house

HDPE is a raw material (low pressure polyethylene) from which PE products are made.

But, like FORUMHOUSE users, we will stick to the "popular" name.

The service life of the pipeline largely depends on the quality of the feedstock. And if in some cases a light water main made of HDPE serves for decades, then in other cases even a properly installed system begins to leak after 1-1.5 years.

The fact is that many companies use plastic waste in the production of HDPE products - the so-called "secondary". Moreover, everything is used, even used disposable syringes. The strength and reliability of such products does not stand up to criticism. And the cold water from them has a sharp unpleasant chemical odor that does not disappear even with time.

pls:

- The easiest way to choose a quality HDPE pipe designed for supplying drinking water for plumbing is to pay attention to its appearance.

A poor-quality product has a black or dark gray color. It does not have letter or number markings. Foreign inclusions or stripes are noticeable in the material. If you smell the product, you can feel an unpleasant chemical smell. Its walls are of different thickness (visible when viewed from the end).

This design can only be used to supply process water.

HDPE design designed for drinking water - black with blue stripes or completely blue. It is made in a uniform color, the material itself is smooth, without inclusions and stripes. The wall thickness corresponds to GOST. A small marking is required (applied by embossing or a marking printer) - “Drinking pipe GOST 18599-2001”. Also must be specified:

• Diameter;
• wall thickness;
• Manufacturer;
• The material strength indicator is marked as follows: PE100 or PE80.

Polyethylene PE100 has a higher density, and hence strength (withstands higher pressure) than polyethylene PE80.

Banned:

- I advise you to choose products on which GOST is applied, there is a manufacturer's marking and the footage is indicated. They are suitable for plumbing.

Alex286:

- In accordance with GOST 18599-2001, according to which pipes for water supply are made, the presence or absence of blue stripes on a HDPE pipe does not yet indicate whether it is intended for drinking water or not.

Some unscrupulous manufacturers may apply blue stripes to low-quality or technical HDPE pipes. Therefore, first of all, you need to look at what is written on the product itself!

The water pipe according to GOST 18599-2001 is made only from low-pressure polyethylene without the addition of recycled materials.

You also need to pay attention to the price - compare the price tag of several manufacturers. Prices are much lower than the maximum and even the average market is enough to alert, because the manufacturer will not trade at a loss. The price of a quality product should be worthy.

Materials for plumbing

How to mount connections

It is not enough to choose a quality product, it is necessary to properly lay the pipeline and install reliable connections. Most often, plumbing HDPE connections are made on collet fittings.

Because there are no metal parts in the flow path of compression fittings, this increases the corrosion resistance of the pipeline system made of this material.

When mounting on push-in fittings, some basic features must be taken into account.

KVladimir:

- Collected the system. Despite the use of fum-tape and a decent tightening, some HDPE fittings leak.

When installing a collet fitting, you should not use linen, tow or fum tape “for additional reliability”.

Benya:

– Push-in fittings are simply tightened by hand and that's it.

The longer the fitting, the more turns it takes to tighten it. Pipes for water supply are inserted into the fitting all the way , and not to the sealing gum.

Sometimes you can hear the opinion that if you lay a HDPE pipeline on the ground, then nothing will happen to it, but this is not so.

– HDPE products are not resistant to sunlight. According to GOST, they are allowed to be stored under the sun for a maximum of two months. And this is in ideal conditions, when the manufacturer fully complies with the technology and uses pipe polyethylene.

How to lay water pipes.

Therefore, the HDPE pipeline is best buried in the ground. Moreover, it is better to do this to a depth below the freezing of the soil, this will allow the fittings not to freeze.

A high-quality modern HDPE pipe can withstand a large number of freezing and thawing cycles without destruction, but for fittings, even the most expensive ones, any freezing is fatal.

The installation process itself is as follows:

1. Dig a narrow trench 2 meters deep.

2. Stones are removed from the trench, otherwise they can push through the walls of the product.

3. Lay the pipe (not tight, this is a general rule!) And sprinkle it with sand.

4. If necessary, the water supply is additionally insulated.

5. The trench is completely buried.

How to lay pipes

It is better to bury a whole pipe without fittings in the ground.

wk96:

– Threaded fittings with a collet are designed to be installed in a place accessible for visual inspection.

Collet connections must be periodically inspected for leaks and, if necessary, tightened.

Therefore, when fittings are buried underground, the maintainability of the entire system drops sharply.

If, nevertheless, it is necessary to make the entire pipeline underground, when doing such work, you can use the advice of a forum member with a nickname technik-san, Moscow . Here is his comment:

– Use HDPE socket fusion fittings for the “underground” connection. The process of connecting HDPE is similar to soldering polypropylene pipes. It turns out a monolithic soldered joint without thread.

Only pipes and fittings of the same type can be welded into one pipeline; for this, a PP-RC soldering iron is used.

The technology of such welding is as follows:

1. The pipe is cut perpendicular to the longitudinal axis, all elements are degreased with isopropyl or isobutyl alcohol (used in antifreeze).

2. The device is turned on, the temperature switch is set to a predetermined temperature - 200-260 ° C. The main thing is not to overheat the thin-walled pipe, because. The melting point of HDPE is lower than that of PP. A pair nozzle is installed on the welding mirror.

3. At the same time push the fitting onto the heated nozzle and slide the pipe into the socket nozzle. The approximate heating time for products of various diameters is written in the instructions for use of the soldering iron.

4. At the end of heating, the parts are removed from the nozzles, connected and fixed. The pipe is fixed in the fitting from 10 to 50 seconds. This is necessary so that, due to the occurrence of increased pressure in the weld, due to thermal expansion, it is not pushed out of the fitting. During this operation, it is forbidden to move the fitting and the pipe mutually.

5. Parts are cooled. Only after complete cooling is the connection mounted in place, and a load is applied to it.

You can also use the following technique - to install threaded fittings on an anaerobic sealant that is difficult to dismantle. It is possible to unwind such a connection only after very strong heating.

Banned:

- When connecting the three collet joints, I smeared the rubber bands with silicone sealant and buried them. It's been 10 years now and nothing is leaking.

Do not bury sewerage and water supply in the same trench! Each pipeline needs an individual trench.

Read the discussion on FORUMHOUSE on what should be and how this material reacts to hot water.

What diameter to choose HDPE pipes

Also, members of the forum are advised to enter HDPE pipes into a private house or country house through a sleeve - a HDPE pipe of a larger diameter (50mm) than a pipe for water supply. Under the sleeve, you can take a cheaper HDPE product designed for supplying technical water, and already in it stretch a line for supplying drinking water. In this case, if it is necessary to repair the main line, the HDPE cold water pipe (32 mm in diameter) can be replaced without digging a trench.

When laying a water pipe from HDPE, the minimum allowable bending radii, which depend on the outer diameter of the pipe, should be taken into account. For clarity, you can use the following table:

SDR is the ratio of the outside diameter of a pipe to its wall thickness. Important point:

The lower the value of the SDR characteristic, the thicker the pipe wall and the more it will withstand the internal pressure in the system.

If you neglect this data, when you try to bend a HDPE pipe in excess of the specified special standards, it can fold in half, this option is shown in the photo:

The times when pipes were made exclusively of metal are long gone. Products made from these raw materials have been replaced by products made from new generation materials, acting as a worthy alternative to metal plumbing systems. Among such products, it is worth highlighting HDPE pipes.

Peculiarities

The demand for polyethylene pipes for water supply is due to the inherent advantages of the material, due to which the laying on the ground or in the ground of highways that provide the supply of cold and hot water has become one of the main areas of use for products, and easy installation of pipes allows you to assemble a water supply with your own hands.

The production technology of products from polyethylene assumes strict adherence to GOST. The regulatory documentation contains tables containing the technical characteristics of such products used in practice.

Taking into account the regulatory documentation regarding the qualities and characteristics of products, HDPE pipes must meet the following requirements:

• regardless of the diameter and size, the outer and inner surface of the product must be absolutely smooth: the presence of bubbles, cracks or any other inclusions is not allowed;
• the entire range of products must be resistant to a pressure of 20 atm.

Pipes that meet the above indicators are produced with a diameter of 16 to 1600 mm. The sale of goods takes place in bays of 100-200 meters or in individual products 12 m long. The products are painted black with longitudinal stripes around the circumference. Polyethylene pipes for cold water supply and hot water supply have certain parameters, on the basis of which they are classified by scope.

Raw materials used to make products. PE 80 pipes are distinguished by high consumer properties, since they are able to withstand high internal pressure on the walls while maintaining the integrity of the structure. Due to the characteristics of the material, they find their application in the construction of pipelines with a diameter of not more than 90 mm.

Products for the production of which PE 100 grade polyethylene was used provide good throughput to a product with a smaller diameter. They are in demand for arranging cold water supply communication schemes. PE 63 is used in residential and industrial construction for drainage of foundations, as well as basements in buildings. In most countries, almost 100% of water pipelines consist of polyethylene pipes.

The level of resistance of pipes to internal pressure. This coefficient is calculated based on the ratio of the product diameter to the wall thickness. Products with a lower index are more durable.

Diameter HDPE pipes. For operation in the private sector, for example, when laying a water pipe in a summer cottage or in a country house, it is recommended to purchase products with a diameter of 25 or 32 mm.

It is worth highlighting the main advantages of HDPE pipes:

• resistance to aggressive media, including salt, acid and alkali;
• durability - the average operational life of products is about 50 years;
• inertness to the liquid medium that passes through the communications;
• resistance to the formation and development of microorganisms on the walls;
• resistance to corrosion, which is important when laying a pipeline in soil that is characterized by high humidity, for example, in garden plots and cottages;
• small mass of products, due to which installation is facilitated;
• resistance to negative temperatures - polyethylene pipes retain their properties at -70 C, due to which they function effectively not only in summer, but also in winter.

In order to have an exhaustive idea of ​​the products, it is necessary to highlight some of the disadvantages of the products, which will be discussed below.

• The material has a low level of UV resistance. Based on this, it is recommended to install HDPE pipes in the soil or place them in special protective cases.
• The strength indicators of polyethylene products are inferior to those of metal pipes.

All products are subject to mandatory control for compliance with state standards established for products that are used to equip the water supply system.

Kinds

The range of such pipes, presented on the modern building materials market, is quite diverse. They are classified according to the scope of use, as well as technical characteristics, for example, by diameter, length and other parameters.

It is possible to distinguish the main types of polyethylene pipes used for plumbing:

• SDR9;
• SDR 11;
• SDR 13.6;
• SDR 17;
• SDR 21;
• SDR 26.

The abbreviation is a dimensional characteristic of the product, which is the value of the ratio of the outer diameter of the pipe to the wall thickness: the thicker the wall of the pipe, the greater the load the material can withstand.

In addition, pipes for water supply are divided into the following types:

• PE 100;
• PE 80;
• PE 63;
• PE 32.

However, among them, only the first two varieties belong to HDPE pipes, since they have a higher density.

In addition, manufacturers distinguish the following options for HDPE pipes:

• pressure products;
• pressureless products.

The latter type of pipe is used in the construction of gravity sewers or storm drains. They are also a fairly effective solution for laying communications. Their main difference is the fact that the products cannot be used when transporting liquid media under pressure.

Pressure structures are in demand when laying water or gas communications, in which the medium moves under a certain pressure.

Based on the section, polyethylene products come in diameters from 10 mm to 1200 mm. The most popular are pipes with a diameter of 20 to 32 mm.

HDPE pipes can be distinguished by the strip applied to the base. The blue line will indicate that the product is intended for the transport of cold water, and the yellow stripe - the product is allowed to operate in the gas pipeline system.

Scope of application

Due to a large list of positive features, such products have a wide range of operation in completely different industries. \

Below are the main areas of application of the products.

• In the first place is the use of HDPE pipes in the sewerage system, especially for domestic purposes. Almost the entire private sewer system includes technical pipes made of low pressure polyethylene. It should be noted that such pipes are used for external and internal installation.
• The products proved to be excellent, acting as a sheath when summing up electrical, television and power cables. They perform a protective function for communication channels and electrical wiring, since they reliably cover communications from mechanical damage.
• HDPE pipes are very popular in the construction of greenhouses in agriculture of various sizes. In this area, products are used for laying irrigation systems for crops, moistening the soil, as well as feeding plants with carbon dioxide.

• When creating ice fields of temporary or stationary value, low-pressure polyethylene pipes play a special role.
• Products act as form-building elements in the monolithic structure of buildings of various kinds.
• Pipes with a large diameter are necessary for arranging the drainage system and pressure conduits.

Due to their high resistance to corrosion, they can be successfully used in many other areas. Resistance to electrochemical corrosion is an important feature of products - such pipes are used in the arrangement of modern communication systems.

Mounting

In order to increase the efficiency of the installation of polyethylene pipes, it is worth exploring the options for connecting two products to each other.

The following methods are distinguished:

• welding;
• compression fittings;
• electrofusion welding;
• flange connection.

The first method is used in practice most often, since it has a high degree of reliability and forms a sealed and durable seam between the structural elements of the water supply system. The welding technology is as follows: the ends of the products are subjected to heat treatment using a welding machine, after which they are fastened to each other - thanks to this, a connection is formed. This method is especially relevant when arranging an underground pipeline.

Fittings are the second most popular way of fixing products together. Today, various compression parts are on sale - tees, couplings, transitional and angle fittings. Such a variety makes it possible to carry out the transition to the thread. Through the use of such elements, it is possible to lay a plumbing system of any configuration. However, it is not recommended to connect communications that will be located underground with such fasteners, since the fittings need regular maintenance.

Electrofusion welding is performed using a special type of fitting - couplings. They include heating elements and terminals. The latter are needed for connection with heating equipment.

The process of connecting products is as follows: fittings are inserted into the pipes at both ends, after which a heating device is connected, due to which the spiral element melts the coupling and the base of the pipe. As a result, a strong one-piece seam is formed at this place.

Flange fastening is used when changing to a thread. This connection option is not widely used, however, when installing a water supply system from HDPE pipes for cold water supply, flanges are very popular.

Light weight and a fairly simple technique that allows you to connect products into one integral structure, make it possible to significantly reduce the time for installation work, as well as perform them yourself without large financial costs and the use of specialized equipment.

In favor of the simple installation of HDPE pipes is also a wide range of connecting elements that are used complete with pipes. They make it possible to lay systems of any configuration, and also allow you to connect elements to each other quickly and as reliably as possible. Experts identify a number of general recommendations that will help you install low-pressure polyethylene pipes without the risk of making a mistake.

Several basic rules should be highlighted.

• All installation work should begin with the creation of a detailed layout of the future water supply system. The drawn up drawings will help to make the most accurate calculations of the number of pipes and connecting elements that will be needed for the highway.

• In the process of self-transportation of purchased products, precautions must be taken to avoid situations in which the products may be damaged by sharp objects or working cutting tools.
• If you plan to lay HDPE pipes in the soil, you must first carry out preparatory measures related to arranging a sand cushion in the trench, the layer of which should not be less than 10 cm. As an alternative to sand, gravel can be used as a raw material for pipe cushions. This additional layer is needed in order to protect the products from the risk of damage to the walls on the sharp edges of various objects that may be in the ground. Before laying pipes, the protective layer must be carefully compacted.
• Products through which cold water will be transported must be laid in such a way that the joints of the water supply elements are slightly recessed into the bulk cushion.

• The laying of products involves several options for connecting elements to each other: one-piece fixation and detachable fastening. The first option involves the presence of welding equipment. In some cases, the method of soldering pipes end-to-end using electrical couplings is used. This method is effective in the case of arranging pressurized water supply systems when using products with a large cross section.

In the second case, work is carried out to help flange or socket fittings, which incorporate an elastic seal. This option is acceptable for communications in which the movement of the liquid medium inside occurs without the participation of pressure (for pipes with a diameter of up to 35 mm). To connect pipes with a detachable method, there is no need to use specialized equipment or tools.

Polyethylene water pipes are widely used in the field of construction, in particular for the reconstruction of water pipes, equipment for swimming pools, lifting water from artesian wells and automated irrigation.

Their selection and installation must comply with GOST 18599-2001.

Construction of HDPE pipes

The structure of HDPE pipes

PND water pipes can be produced in the form of bays of 100 and 200 m, as well as sections of 12 m. Their inner and outer surfaces must be smooth.

Slight waviness and longitudinal stripes are acceptable, but they should not go beyond the permissible deviations from the norm, as regards the thickness of the pipe wall. In addition, the presence of shells, cracks, and various foreign inclusions on the inner, outer and end surfaces of the pipe is not allowed.

The HDPE water pipe must be black or black and blue. Blue here make longitudinal marking stripes, which must be at least three. The stripes are distributed evenly around the circumference. Also, pipes can have a blue color of non-regulated shades.

The main parameters of polyethylene pipes

There are several basic parameters by which you can distinguish. All of them have a significant impact on the area in which the HDPE water pipe will be applied.

There are three main indicators:

1. An indicator of the brand of polyethylene. There are two grades of polyethylene - PE100 and PE80.

• water polyethylene pipes PE100 - this is a significant savings in material when using large-section pipes. Given this, such pipes are mainly used for the construction of cold water mains.
• PE80 pipes have good consumer properties. They are distinguished by their ability to withstand the high internal pressure of the liquid that is transported through the pipes. The PE80 brand is an ideal solution for a water supply network with a small cross section (up to 90 mm).

1. Index of resistance to internal pressure SDR. This is the ratio of the diameter of a polyethylene pipe to the thickness of its walls. HDPE water pipes with a lower SDR are more durable.
2. Diameter .

Advantages of polyethylene pipes

Polyethylene has a number of advantages over other types of pipes (metal, cast iron, concrete):

Polyethylene water pipes are economical, easy maintenance, good strength properties and the ability to withstand a high level of stress.

• high elasticity;
• ability to withstand variable soil loads;
• ability to withstand earthquakes;
• the inner surface of plastic pipes has a low roughness. This makes it possible to use an order of magnitude lower diameter, while maintaining the hydraulic properties of the pipeline.
• HDPE water pipe can greatly reduce the risk of water hammer. This is achieved by a relatively low modulus of elasticity of the material;
• water frozen inside the water polymer pipe will not harm the pipeline;
• toxicological and bacteriological safety of pressure polyethylene pipes;
• ease of maintenance and easy repair/replacement polyethylene pipes.

Features of the installation of polyethylene pipes

The main difference between the installation of polyethylene water pipes is ease and convenience. The HDPE water pipe can be equipped with a wide range of connecting fittings, commercially available adapters that allow it to be connected to pipes made of other materials.

The range of application of parts for connection, among other things, is quite wide. All this made HDPE water pipes a versatile material that is successfully used in water supply networks.

Polyethylene pipe connections and their types

There are two types of connections for water polyethylene pipes:

• permanent connections. Welding equipment is used here, welding is carried out by butt or electrofusion method.
  This method of connecting polyethylene pipes is used if the pipes are planned to be operated under pressure.
• detachable connections. They are bell-shaped or flanged with elastic seals. These connections have found their application for the installation of non-pressure plumbing systems.

Each individual case requires an individual approach to the choice of installation method, as well as the connection of water polyethylene pipes.

An important factor, taking into account which specialists, when installing water pipes, opt for HDPE pipes, is their relatively low cost, which, taking into account all the positive properties listed above, is really a godsend. Both the pipes themselves and the consumables (fittings) that are used for connection are of low cost.

Rules for laying polyethylene pipes

When starting to lay polyethylene pipes, it is necessary to take into account the thickness of the soil layer that will be located on top of the pipe. This layer should not contain third-party objects and large stones that can damage the pipe.

Directly under the pipeline, it is required to lay a substrate of fine gravel or sand. Its layer should be 10 cm thick or more. Gravel or sand must be well compacted. The HDPE pipe for the water supply, after preparing the bottom of the ditch, is laid in such a way that its joints are slightly recessed into the sand.

The HDPE pipe for water supply must be transported in the body of a car, where there are no objects that can damage it, for example, nails, cutting tools, scraps of metal structures and glass.

Having correctly selected and installed a polyethylene pipeline once, you will most likely never need to return to this issue again. At the same time, throughout the entire period of operation, the pipeline will not lose the qualities inherent in it initially during installation.

• Profitability. During the construction of water supply networks using HDPE pipes, savings of up to 40% -45% of funds are created, compared with traditional methods;
• Durability. The service life of HDPE pipes is 50 years;
• Unpretentiousness. Easy to maintain. Pipes do not need cathodic protection and therefore require almost no maintenance;
• Its technology. Resistance to corrosion and chemical influences. Polyethylene pipes are not interconnected with aggressive environments;
• Impact resistance and elasticity. Reducing the possibility of destruction of the polyethylene pipeline during the freezing of the liquid, since the HDPE pipe does not collapse, but expands in diameter, acquiring the same size when the liquid thaws;
• Light weight, which greatly facilitates and reduces the cost of installation work;
• Reliability. Welded seams retain their strength throughout the life of pipelines made of polyethylene pipes;
• Safety of polyethylene pipes;
• Environmental friendliness. The inner layer of this HDPE pipe does not give water any harmful impurities.

Pipes can be used for cold domestic supply, construction of irrigation and low-pressure water supply systems.

Transportation of HDPE pipes

The ease of transportation of PE pipes, due to the rather light specific gravity. Loading and unloading equipment is not required. Possibility of telescoping pipes.

HDPE pipe installation

The connection of HDPE pipes occurs due to electrofusion, butt welding, as well as with the help of compression fittings.

Service life - 50 years.

Main technical characteristics

• SDR index - 11, 13.6, 17, 17.6, 21 and 26;
• material - low pressure polyethylene (HDPE);
• grades of polyethylene -, and;
• execution - bell-shaped or bell-shaped.

Detailed specifications are in each product card. There you can see the diameter (nominal, outer and inner), weight per linear meter, wall thickness, etc.

PND polyethylene pipes for cold water supply are connected by means of fittings. Electrofusion and butt welding is acceptable.