Polyethylene pipeline products are widely used for laying pipelines for various purposes. Therefore, it is important to know the performance properties of products and what the main technical characteristics are polyethylene pipes. The information provided in this article will help you more accurately determine the best option for using polyethylene products for installing a plumbing or other system.
Properties of polyethylene
To a greater extent, the physical parameters of pipes are determined by the properties of the material from which they are made. Polyethylene is one of the most popular types of plastic, from which many products are made, including pipelines. The popularity of polyethylene is due to a whole arsenal of positive properties, thanks to which it differs for the better from alternative products. The main ones:
- resistance against solar ultraviolet radiation and high humidity, thanks to the addition of special modifiers in production;
- immunity to acids, alkalis and alcohol components;
It must be taken into account that polyethylene is easily affected by liquid chlorine and fluorine. PE products are destroyed by interaction with these chemical elements. True, it is almost impossible to encounter these destructive chemical elements in free form.
- low density of polyethylene pipe (about 0.950 g/cm³), which makes it light;
- the ability to withstand fairly high temperatures without changing its shape and structure;
- high elasticity;
- The low weight of the polyethylene pipe means that the products do not sink in water and are very easy to transport and carry out loading and unloading operations.
Due to these properties of polyethylene, it has found application in the manufacture of pipeline products for laying mainly water, gas and sewer systems.
Main parameters of PE pipes
The most significant and essential are the following main ones: specifications PE pipes:
- Operating temperature and pressure.
- Product diameter.
- Specific gravity.
- Throughput (roughness).
- Margin of safety.
- Elongation at break and after heating.
- Thermal stability.
- Service life (more than 50 years).
Working temperature
Manufacturer according to technical requirements the temperature of the working medium transported through polyethylene pipes is set to no more than 40.0ºС, therefore PE plumbing products are marked with a blue stripe (pipes for gas supply are marked with a yellow stripe). The lower limit of operating temperature is 0ºС.
Despite the established range, a polyethylene pipe is quite capable of withstanding the temperature of the working environment up to 80.0ºС (of course, not constantly). When water in a polyethylene pipe freezes in the cold season, it does not collapse, but only stretches a little.
Operating pressure
The pressure of the working environment for which the product is guaranteed to be designed depends on factors such as:
- Brand of polyethylene used. Polyethylene PE32 has low strength, while PE 80, and especially PE 100, are high-strength materials.
- Wall thickness (from 2.0 to 60, mm). The thicker the wall, the more pressure the pipe will withstand.
- Pipe diameter. The larger the diameter of the product, the less force of pressure per cm² the pipe experiences.
As a result, the operating pressure for a PE water pipe is in the range from 6.0 to 16.0 atmospheres. This value is indicated in the marking after the SDR symbols.
Diameter
PE pipes, the characteristics of which meet the technical requirements, are produced with different diameters ranging from 10.0 mm to 1200.0 mm. For residential or private water supply, it is enough to use products with a diameter of 20.0 mm. Large-diameter pipes are used for pipelines that supply water to large industrial facilities or entire residential areas.
Specific gravity
The specific gravity of a PE pipe depends on the diameter and wall thickness of the product. It is very easy to calculate it yourself. To do this you need:
- Measure the radius of the pipe and calculate the area of the linear meter of the product.
- Multiply the calculated area per meter by the thickness of the pipe wall and the density of the polyethylene.
The obtained values show that polyethylene pipes with a large diameter are characterized by a specific weight of more than 200 kg per linear meter, so manual installation of such products without the use of special equipment is impossible.
Bandwidth
The degree of smoothness (roughness) of the inner surface very significantly affects the throughput of the pipe. PE products are characterized by a small roughness coefficient (up to 0.1). This property allows the use of pipes one step thinner in diameter compared to steel products.
Margin of safety
To ensure the safe operation of water pipelines, all polyethylene products are manufactured with a sufficient margin of safety. The safety factor characterizes how much load the pipes can withstand from the declared operating parameters. For PE pipes it is equal to 1.250 (water supply) and up to 3.150 (gas pipeline).
Elongation and thermal resistance
Thanks to these parameters, the degree of plasticity of the pipes is determined. Tests of polyethylene pipes show that quality products are influenced by significant mechanical loads They don't break, they just stretch. The mechanical pressure threshold is 16.0 MPa (for PE 80) and 21.0 MPa (for PE 100).
When exposed elevated temperature per product, its length according to the technical specifications increases by no more than 3%.
The thermal stability characteristic determines the resistance of pipes against oxidation when exposed to high temperatures for more than 20 minutes.
The procedure for storing PE pipes
Their further operation with the specified characteristics depends on the conditions of safety of PE pipes. Storage of polyethylene pipes can be organized in a warehouse or outdoors. When storing pipes in a warehouse, they are laid parallel to each other on a clean and level surface. Sudden changes in air temperature are not desirable indoors.
To protect products outdoors, a canopy is required. You can simply cover the products with plastic film or a durable awning.
Special technical specifications which must be followed to ensure the safety of the pipes:
- Wooden spacers must be laid along the length of the pipes at intervals of 1 meter.
- When storing pipes in pallets (when delivered directly from the factory), they are allowed to be stacked on top of each other in no more than four tiers. In this case, it is necessary to control that the bulk of the weight falls on the wooden frame.
- The stack of polyethylene pipes should not exceed 1.50 meters.
- Products must lie straight without bending and not be subject to physical impact.
- The distance to heating (heating) devices must be at least 1 meter.
Thus, the article provides almost all technical characteristics of polyethylene pipes. Products that have all the necessary positive parameters are absolutely suitable for use as a pipeline for water supply or other main systems throughout the entire declared service life.
Most modern pipeline systems is made of polyethylene - a polymer material with unique properties that distinguish it favorably from traditional construction pipe products. The latest production technologies have made it possible to put the strength characteristics of polyethylene pipes almost on the same level as steel pipes, and even higher in terms of wear resistance and durability.
Basic properties
All are created from a thermoplastic polymerization product of a lower hydrocarbon - ethylene, which gives products made from it similar characteristics:
- The density of the pipe material is 0.94-0.96 g/cm 3,
- The operating temperature ranges from -60 to +90 0 C, the optimal mode is from 0 to 40 0 C,
- Permissible operating pressure of the contents – up to 16 atm,
- The diameter of polyethylene pipes can be from 20 to 1600 mm,
- The wall thickness varies from 2 to 60 mm.
ATTENTION! The indicated numbers are correct for most brands of polyethylene, but there are exceptions. There are types of polyethylene materials, products from which can withstand much higher loads - mechanical, chemical and temperature.
Advantages
Polyethylene pipes have a very long service life - more than 60 years under standard conditions, which is explained by the following capabilities of this material:
- Elasticity, due to which the pipe does not deteriorate even when its contents freeze. In this case, it can only be slightly deformed - stretched in diameter.
- Resistant to common chemical reagents - various acids, alcohols and alkalis, and for some types even to fats and gasoline products. Polyethylene cannot withstand contact only with liquid fluorine and chlorine, but these substances are extremely rare in their pure form, so such contact is unlikely.
- Resistant to biodegradation through rot and fungus, as well as destruction by insects and rodents.
- The period of natural decomposition is more than 100 years.
- Absolute absence of toxic emissions, which allows them to be used in direct contact with food products and laid without additional protection.
- The ability to be an excellent insulator for liquids and gases, which allows nothing unnecessary to pass in or out.
- Smoothness of the inner walls. This factor determines the small percentage of their contamination and the appearance of growths.
- Low weight of products. Polyethylene is even lighter than water, due to which the installation of communication systems involving polyethylene pipes does not require strengthening the supports, especially strong fasteners and the use of great physical force.
- Ease of installation work. To connect individual sections of pipes, gentle heating or fastening with sockets and couplings is sufficient.
INTERESTING! Polymerized ethylene can serve as an excellent sound insulator. The use of polyethylene pipes instead of their metal counterparts helps to significantly reduce the level of noise coming from communications.
Flaws
Despite all the versatility of PE pipes, they have disadvantages associated with the structural features of the material:
- The products do not withstand high temperatures; they are intended mainly for transporting cold liquids and gases.
- Pure polyethylene becomes brittle after prolonged exposure to sunlight. To protect against ultraviolet radiation, pipes are treated using one of the following methods:
- covered with paint (preferably acrylic),
- blocked with protective materials,
- Even at the manufacturing stage, special protective substances are added to polyethylene.
Features of polyethylene pipes
Polyethylene has many varieties, which are the result of different technologies for its production. Together with the differences in design, we get pipes with different technical characteristics that can be used for a wide variety of needs.
Materials
The material for making PE pipes can be:
- LDPE is a low-density polyethylene product manufactured using high blood pressure,
- HDPE is a high-density polymer produced at low pressure,
- Supermolecular, or cross-linked polyethylene, having a very high density and strong intermolecular bonds, similar to the crystal lattice of the most durable solids.
The higher the density of a substance, the harder, stronger it is and the higher its melting point. Thus, “cross-linked” polyethylene melts only at temperatures above 170 0 C, and pipes made from it can easily withstand pressures of up to 25 atm. However, this results in the loss of such properties as the elasticity of the material and the flexibility of tubular products, which in some cases may be even more useful than strength.
Constructions
Depending on the purpose, PE pipes are manufactured:
- Various diameters and wall thicknesses. Products with thicker walls can withstand greater pressure, that is, they can be used for pressure or non-pressure water pipes, sewers, etc.,
- Single or multilayer, in the production of which the same or different materials are used to make each layer. Give greater tensile and tear strength while maintaining elasticity and smoothness of internal surfaces (for example, corrugated on the outside and smooth on the inside).
- Reinforced, perforated and others that have higher rates for those characteristics that need to be improved for the specific purpose of the pipe.
In this article we will examine what technical characteristics and performance properties polyethylene pipes have.
Material
To the greatest extent, the properties of any object are determined by what it is made of. Polyethylene pipes are no exception.
And they are made from a material that is the most common plastic in existence.
His physical properties are:
- Polyethylene does not react with acids, alkalis and alcohols. But it can be destroyed by liquid chlorine and fluorine.
However, this usually does not threaten the vigilant owner of a polyethylene water supply: the probability of encountering fluorine and chlorine in a free state is much less than the probability of encountering the British Queen in the restroom of the Zhmerinka bus station. - Polyethylene is somewhat lighter than water. Its density is approximately 0.94-0.96 g/cm3. Note: the fact that he does not drown in water does not characterize him in a bad way.
It's just lightweight plastic. The weight of a polyethylene pipe of small and medium diameter will seem manageable even to a person who is far from the world record in powerlifting. - Polyethylene begins to soften and lose its original shape at a temperature of 80 C.
- He's afraid of the light. Under natural conditions, polymerized ethylene turns into dust in about a year. Don’t rush to mourn your new canister: to prevent this from happening, the industry uses special modifiers that make polyethylene almost eternal. Environmentalists are crying at this point.
How much cleaner it would be if all polyethylene decomposed within a year...
Advice: after all, it is advisable to deepen the entrance to the house below the freezing point of the soil. If the internal water supply warms up as soon as the temperature in the room rises above zero, then in the snowdrifts at -30 outside it is still a pleasure.
In addition, during the winter absence, it is advisable to drain the water from the pipes for one more reason: ice is not harmful to the pipes, but it will break the faucets.
Pipe Specifications
The technical characteristics of polyethylene pipes arise from the properties of the material.
Working temperature
For all polyethylene pipes without exception, the operating temperature is limited to 40 degrees Celsius. Anything beyond that is at your own peril and risk. The manufacturer did not promise you this.
The lower limit of the operating temperature is 0 C, the freezing point of water. This does not mean that at -10 the pipe will already crumble into dust: it will survive the cosmic cold just fine, but water will not be able to circulate through it. It will simply turn to ice.
Operating pressure
For a pipe, the maximum operating pressure is determined by several factors:
- Polyethylene brand. Low-density polyethylene PE32, all other things being equal, is much less durable than high-density polyethylene PE100.
- Wall thickness. I think there is no need to explain. The thicker the wall, the stronger the pipe.
- Pipe diameter. Large-diameter polyethylene pipes have a much larger internal surface per linear meter.
Every atmosphere overpressure- This extra kilos per square centimeter of area. More area- greater total pressure. And all these kilograms are trying to stretch a wall of a fixed thickness!
In general, the maximum operating pressure is from 6 to 16 atmospheres. The operating pressure is indirectly indicated by the numbers after the letters STR in the marking: the lower this parameter, the more resistant the pipe is to pressure.
Diameters
The diameters of polyethylene pipes completely depend on the application. In internal water pipes In private houses and city apartments, the most popular diameter is 20 mm. Large-diameter polyethylene pipes are used in the installation of pipelines supplying water to large areas of the city. They can also be used as walls of wells.
According to current regulatory documents, the minimum diameter of a polyethylene pipe produced is 10 mm, the maximum is 1200. Wall thickness varies from 2 mm to 6 centimeters.
Specific gravity
The weight of polyethylene pipes is directly proportional to its diameter and wall thickness. It is easy to calculate by multiplying the surface area of a linear meter of pipe (it is calculated as S = 2 π rh, where r is the radius of the pipe, h = 1 m) by the wall thickness and density of polyethylene.
Thus, large-diameter polyethylene pipes used for water supply mains with a diameter of 1200 millimeters and a wall thickness of 6 cm will weigh: 1.2 * 3.1415 * 1 * 0.06 * 960 = 217 kg per linear meter.
In order not to leave any ambiguities: 1.2 is two radii of the pipe in meters, 3.1415 is the number pi, 0.06 is the wall thickness, again in meters, 960 is the specific gravity of a cubic meter of high-density polyethylene.
As you can see, in the case of a large diameter, the weight of the polyethylene pipe makes manual installation impossible.
Roughness
When calculating the capacity of a pipe, it is necessary to take into account its resistance to water flow. It, in turn, linearly depends on the state of the inner surface.
The roughness level of polyethylene pipes is estimated at approximately 0.005 mm or less. When calculating the required clearance, the roughness coefficient of polyethylene pipes is taken equal to 0.01 - 0.1.
In order not to frighten with strange and obscure formulas, let's say this: with a pipe diameter of up to 80 mm, a polyethylene pipe can be installed one step thinner than a steel pipe. 32 instead of 40 mm and so on. For larger diameters, friction against the walls has a lesser effect on the flow velocity, so the diameter is taken the same.
Margin of safety
With a stated operating pressure of, say, 10 atmospheres, the pipe should actually withstand much more. This has a direct bearing on the safety of operation of water and gas pipelines.
The safety factor of polyethylene pipes is taken to be 1.25 for water and 2.0 - 3.15 for gas lines.
Durability
The service life of polyethylene pipes is estimated to be an undetermined “50+ years”. On the practical side, believe me, the walls of the house will require major repairs much earlier than a properly assembled polyethylene water supply starts to flow.
Advice: among modern materials, durability can only be thought of in the case of non-galvanized steel pipes.
For everyone else, it’s better to compare other consumer characteristics, otherwise you can get depressed: they will probably live longer than you and me.
Conclusion
Having found out what technical characteristics polyethylene pipes have, you can make a choice in their favor or choose another material. In any case - good luck!
Or heating was considered a novelty, but today they have found quite wide application. Polyethylene pipes, the technical characteristics of which greatly distinguish them from metal ones, sometimes serve their owners for more than 50 years. So what is their feature?
Review of polyethylene pipes
The first and main advantage of such a pipe is its resistance to corrosion. It is thanks to this that they can withstand a fairly long period of time without repair. In addition, polyethylene and sewerage are not exposed. Their internal part is smooth, which can significantly increase throughput. Even after many years of operation, polyethylene pipes for water supply, heating or sewerage have much better flow than metal ones, due to the fact that no deposits remain on their walls. Shaped parts can be created not only from plastic, but also from metal. In addition, condensation cannot form on their surface. These advantages are what made polyethylene pipes (their technical characteristics will be described below) so popular.
Characteristics of polyethylene pipes
If we consider polyethylene pipes (technical characteristics) for sewerage, water supply or heating, then first you need to pay attention to the brand of material that is used in their composition, then we can talk about the resistance of the pipe to pressure from the inside and the diameter of the product. That is why, if you want to learn more about what polyethylene pipes are, study their technical characteristics and features, you should first familiarize yourself with what types of polyethylene there are:
- PE 63 (not currently used).
- PE 80 - has good properties and can withstand quite high pressure of any liquids. This brand is used in the creation of small diameter pipes that are laid for water supply.
- PE 100 - used to create pipes with large diameters, which are used in the construction of cold water supply lines.
The diameter, which is also included in the characteristics of polyethylene pipes, can be completely different. The range is from 20 mm to 120 cm. Their length largely depends on what their diameter is. So, for example, from 20 to 110 mm suggests that its length will not exceed 50 meters.
Advantages of large diameter polyethylene pipes
IN Lately Large diameter pipes are in greatest demand. This can be explained by the fact that they are used for the construction of pressure water pipelines, drainage system, or sewer. They have several important advantages over metal models:
- Production, installation and operation are cheaper than in the case of metal.
- If the water inside freezes, nothing bad will happen.
- The weight of the pipe is significantly lower, making transportation and installation easier.
- Technical polyethylene pipe is safe and non-toxic.
- There is no need to worry during transportation, as they are not dangerous goods.
- Resistant to impacts and stretching. The connections are more reliable and durable, which increases the service life of the pipe.
Polyethylene sewer pipes
Thanks to polyethylene, sewerage has acquired the new kind, and its quality has improved significantly. The fact is that polyethylene helps improve the development of the system itself, and its construction is much easier and faster. For example, you can use the so-called trenchless installation. Polyethylene pipes, the technical characteristics of which help them not to be affected by even strong chemicals, can be easily transported and installed. Their connection is considered more durable and reliable, which helps protect against accidents.
Corrugated polyethylene pipes
This one for sewers and water pipes is made of special two-layer polyethylene. As a rule, they use the PE 80 brand, which is most suitable in diameter for this model. The pipes are resistant to chemicals. Due to the special ring rigidity, which is quite high, corrugated polyethylene pipes can be installed using a hidden method at a depth of one to twenty meters. There are also ones made of polyethylene for the so-called external sewer drains.
Pressure pipes for sewerage and water supply
The grade of polyethylene 80 is the most durable of all known today. That is why it is used to create special polyethylene pipes that can withstand both high and low pressure. They can be used without problems even in very aggressive environment, but the main area of application is still water supply. They are not suitable for sewers. The most popular diameter of such pipes today is from 2 to 6.3 cm.
Well-known manufacturers of polyethylene pipes
In construction stores today, the huge variety and assortment of polyethylene pipes is simply dizzying. If you don’t know which pipes are best to purchase, you should first find out who produces these models.
The most popular company producing polyethylene pipes for sewerage and water supply today is Rehau. It creates high-quality and fairly durable products that are suitable for water supply and sewerage systems of any complexity and length. In addition, the polyethylene water pipe, the technical characteristics of which indicate its high quality, is characterized by ease of assembly, ease of transportation and the lightness of the system itself.
Wavin from Holland produces polyethylene pipes for sewerage. By choosing this company, you will forget what repairs are for a long time. The main feature of Wavin polyethylene pipes is that they have high noise insulation properties and can also withstand high temperatures (up to 90 degrees).
Russian manufacturers also keep up with foreign ones and produce pipes from high-quality polyethylene, the so-called low pressure. Such models are characterized by lower cost, and therefore are quite popular among builders and buyers.
