What is SDR of plastic, polypropylene, polyethylene pipes. What kind of indicator is SDR for pipes? SDR transcript

Polyethylene pipes, like any other, have a marking system. It may be difficult for novice builders to understand what a polyethylene pipe SDR 11 is or what is encrypted in the marking “PE 80 SDR 21”.

Our article will explain the meaning of the necessary parameters, in addition, it presents a brief technological characteristics and the main areas of application of the most popular types of polyethylene pipes.

What are SDR and PE?

SDR is the ratio of the outer diameter of a polyethylene (or any other) pipe to its wall thickness. Thus, with an increase in the SDR index, the pipe wall becomes thinner, and vice versa, the wall thickness increases with a decrease in the index.

After the prefix PE (“polyethylene”), manufacturers indicate the brand of polyethylene. Nowadays, PE-80 and PE-100 are most often found.

The materials have some differences:

PE 100 has a more ordered crystal lattice structure, due to which, after welding, a stronger and more uniform weld can be obtained.
However, due to the first difference, PE 80 polyethylene requires a lower temperature for soldering.
PE 100 grade material is generally more dense and durable, which means it can be used in more severe operating conditions.
The production of pipes of the required diameter will require a larger amount of PE 80 polyethylene (compared to its analogue), which increases the cost of the final product, as well as the cost of delivering it to the construction site

In the article “” you can get acquainted with these indicators in more detail.

Pro tip: There may be an opinion that since grade 100 polyethylene is more reliable, resistant and cheaper, it is better to use only it. However, in practice, each type of pipe has found its optimal application. Let's look at them in more detail.

Characteristics of products made from PE 80

PE 80 SDR 21

These are low-pressure pipes that are intended for use in the installation of free-flow and low-pressure sewer systems created in small areas. apartment buildings. It is possible to create pressurized water supply for small open areas. This type of pipe is fully certified for the use of pipelines providing cold water supply and sewerage. Experts do not recommend the use of such pipes in the following cases:

installation of gas pipelines due to insufficient pipe wall thickness,
laying main pipelines, since excessive compression can lead to physical destruction of the pipe.

PE 80 SDR 17

The polyethylene pipe SDR 17 is distinguished by the average value of the ratio of the outer diameter of the pipes produced today to the thickness of their wall. PE 80 SDR 17 pipes are recommended for use in a very wide range. They are used:

for water supply systems intended to supply drinking water;
for water supply systems for household purposes from facilities where water treatment is carried out to the consumer;
for installation of irrigation systems.

The choice of these pipes for installing communications in a low-rise building is considered optimal, since their installation will ensure high strength, lightness of the pipelines, and the cost of purchasing the material will be relatively low.

PE 80 SDR 13.6

PE 80 SDR 13.6 pipes are low pressure pipes and are recommended for use in the installation of pipelines transporting cold drinking water.

The high technical qualities and consumer characteristics of this type of pipe are due to the use of an improved grade of polyethylene (PE80) and the use of a new method in the process of cleaning raw materials.

Pro tip: Due to the long warranty period (up to 70 years), such pipes are widely used in creating long-term water supply systems.

Characteristics of products made from PE 100

PE 100 SDR 26

These are pipes for transporting household and drinking water in urban and suburban environments. For their production, PE100 polyethylene is used, the distinctive qualities of which are high density, due to which pipes made from this material are superior to products made from PE80 in long-term strength and resistance to cracking.

In addition, the quality characteristics of the material made it possible to significantly reduce the wall thickness of the product, which lightened its weight. PE100 pipes are recommended for widespread use in the following cases:

for installation of water pipelines;
for pipelines intended for the transport of liquid food products, for example, in the production of milk, juices, brewing and winemaking.

PE 100 SDR 21

PE 100 SDR 21 pipes are used for the construction of water pipelines. Passing through pipes of this type, water retains its taste and is characterized by the absence of foreign odors.

This type of pipe can be successfully used if it is necessary to use it together with steel pipes, since the special detachable and one-piece adapters that are equipped with the ends of each pipe of this type (plastic at one end, metal at the other) provide the possibility of connection as with plastic , and with steel pipes. Corrosion processes, other types of destruction and blockages in such pipes are not dangerous.

PE 100 SDR 17

Products marked PE 100 SDR 17 are new generation pipes due to the use of advanced technologies used in the production of PE100 polyethylene. A special feature of these products is their uniquely high strength indicators, which has a significant impact on enhancing the performance characteristics of polyethylene pipes.

Pipes of this type are recommended for use in pressure water supply systems and gas pipelines. Moreover, such pipes are considered ideal for the installation of pipelines with a large cross-section. When manufacturing pipes of this type, material savings are very significant due to the possibility of reducing the wall thickness while maintaining the high strength of the product. The technical characteristics of such pipes allow their widespread use in the construction of long-distance pipelines.

PE 100 SDR 11

Polyethylene pipe SDR 11 is made from polyethylene produced at low pressure. At the same time, the high density of the material of PE 100 SDR 11 pipes allows them to be used for water supply systems with high pressure. The material used for the manufacture of pipes ensures high quality and environmental safety drinking water.

Pipes of this type are suitable for operating systems with advanced water supply capabilities. It is possible to use such pipes for the installation of sewer collectors - the chemical resistance of the material used in production ensures high strength and durability of the pipes. Laying such pipes is possible in any type of soil.

This is a characteristic of the most commonly used types of polyethylene products for pipelines. It is worth noting that the quality finished products The brand of polyethylene pipes is greatly influenced by the brand, and this factor must be taken into account when purchasing.

Any pipes have a certain marking system. We propose to consider what SDR pipes are, what they are needed for and what is unique about the use of these building materials.

Marking of polyethylene pipes

SDR is a unique pipe designation system that determines the ratio of the outer size of the service to the wall thickness. Accordingly, the lower this indicator, the thicker the pipe and vice versa. In this case, the designation SDR is most often used in relation to polyethylene pipes. In this case, the combination of letters PE is added to the marking. For example, a PE 100 SDR 11 pipe is a polyethylene pipe made of polyethylene 100 with a ratio of outer diameter to wall thickness of 11 mm. Schematically it looks like this:

Nowadays, the most commonly used polyethylene pipes are SDR, made of plastic types 80 and 100. Each grade has its own characteristics:

Polyethylene grade 100 is considered to be of higher quality, because it has a grouped crystalline structure, thanks to which they are better suited for welding;
PE 80 SDR pipes are easier to melt with your own hands; lower temperatures are required for the diffusion of molecules;
100th polyethylene is more often installed in extreme conditions, it is more rigid;
Any of these polyethylenes are used for water supply cold water, but PE 100 can also be used for heating, pressure sewerage and connecting a boiler.

Installation of SDR series pipes is carried out similarly to standard polyethylene materials - using welding machine or electric couplings, but due to the density of the molecules, the seam is more dense and airtight.

Peculiarities

In order to better navigate SDR-type products, it is necessary to study their main characteristics. Let's discuss the most popular pipes from the SDR series.

PE 63 SDR 11 are polyethylene pipes made of specially treated plastic. Basically, pipes of this series are used for cold water supply to a private home. They do not tolerate temperature changes well and can crack due to the fact that there are greater distances between polyethylene 63 crystals than between PE 100 molecules. Therefore, craftsmen recommend using them only for interior work. The main advantage of the material is its low price, the cost per linear meter is from 25 rubles.

HDPE PE-63 SDR 17.6 made in accordance with GOST 18599-2001 (2003) are water supply pipes that are used in systems with a pressure of no more than 10 atmospheres. Such communications are suitable for supplying cold water to a pump or boiler. It is not recommended to use this material for hot water supply or heating, since the pipes have a fairly high deformation coefficient - they can be deformed from high temperatures.

PE 80 SDR 13.6 is the best option for arranging home plumbing. They do not tolerate temperature changes well and are used at home. If necessary, you can equip communications and external water supply, but in this case you will need to additionally insulate the materials.

PE 80 SDR 17 have an optimal ratio of cost and quality. The wall thickness allows the materials to be used in a wide variety of industries, ranging from home production and ending with industrial water supply.

PE 100 SDR 11 are the densest pipes in this series, made from grade 100 polyethylene. They perfectly withstand any load of the heating, sewage or drainage system. Their disadvantage is considered to be high weight due to the density and strength of the walls. To install the system, you will need to use additional lifting mechanisms. Communications are mainly used in heating processes or to provide water to a small residential building, for example, a country house or cottage.

The PE 100 SDR 17 pipe is made in accordance with GOST 18599-2001 from polyethylene grade 100. These are mainly household communications that are necessary for supplying water to residential multi-storey buildings or private cottages. This type of material is durable and strong. The average service life of pipes is 50 years; they are often used in extreme operating conditions.

Photo: PE 100 SDR 17 pipe

Due to the relatively thin walls, it should be noted the ease of these communications. This allows them to be installed at home without the use of various lifting mechanisms. Scope of application of pipes of the PE 100 SDR 17 series:

Water supply;
Private production;
Drainage.

PE 100 SDR 21 is especially popular among many home craftsmen. These are unique polyethylene pipes that do not impart the characteristic smell of plastic to the liquid passing through them. Because of this, they are often used to organize the water supply of a residential building with drinking water and watering delicate plant crops (strawberries, cucumbers, grapes).

The tight fit of polyethylene molecules and the optimal ratio of diameters to wall thickness make it possible to ensure a strong and hermetic fastening using these communications, even when using different types of pipes. Professional plumbers recommend combining this brand with steel communications.

Application area:

Heat supply of a residential building;
Providing watering;
Pressure sewer and drainage systems.

PE 100 SDR 26 are reliable and durable communication materials. Thin walls will allow the pipes to be successfully used to provide water supply to any home. In addition, they are widely used in winemaking. Thin walls have a positive effect on the flexibility of pipes, without worrying about their strength. The SDR 26 grade is made from polyethylene produced under low pressure, which makes it resistant to temperature and pressure changes within the drainage or heating system.

Area of use of SDR 26:

Winemaking and other home production;
Cold and hot water supply;
Heating at a coolant temperature of no more than 75 degrees.

Of course, polyethylene 100 is quite durable and interesting material, but its price is quite high compared to other brands. Cost of SDR PE 100 pipe:

This is almost twice as high as other reinforced pipes with similar diameters, made of cheaper polyethylene, for example, PE 63.

There is also a separate type of SDR pipes that are reinforced with a sealant, for example, this is material from Rubis. PRO AQUA PN25 SDR 6 RUBIS and PRO AQUA PE25 SDR 6 RUBIS are communications made of three-layer polypropylene or polyethylene (depending on the marking). Moreover, each layer of plastic is also reinforced with a special reinforcing substance, most often it is thermal fiber. Such pipes not only have excellent rigidity, but also resist temperature changes and freezing of water in them. They are used for arranging street sewerage, external water supply or shallow drainage systems.

Advantages of the PRO AQUA SDR series:

Durability over 50 years;
The material is not susceptible to corrosion processes;
The eraser does not salt or mineralize, unlike metal compounds;
The dense crystal lattice of this plastic allows for a more rigid and airtight fastening;
PRO pipes are known for their small linear expansion, i.e. even with strong temperature changes, they do not deform.

Recently, polyethylene pipes (PE) have gained great popularity, and their scope of application is very wide. In this article we will get acquainted with the markings of these pipes, and also consider their features and the areas of construction in which they are used.

Marking

What does SDR mean?

First of all, let's look at what SDR pipes are. So - this abbreviation means the ratio of the outer diameter to the wall thickness.

Thus, SDR is calculated using the formula – SDR=D/R, where:

D – indicates the outer diameter;
R – Product wall thickness.

Accordingly, the greater this value, the thinner the wall. For example, a pipe SDR 17 - its marking means that the outer diameter of the product is 17 times greater than the wall thickness.

PE grades

In addition to SDR, the marking uses a letter designation (“PE”) and a numerical designation consisting of two numbers. For example, a PE80 SDR11 pipe - as you might guess, PE indicates that the product is made of polyethylene. The numerical value corresponds to the minimum long-term strength of polyethylene (MRS), in this case it is 8 MPa.

The most popular products are the brands PE100, PE80 and PE63. Pipe polyethylene, which is used in their manufacture, is obtained from a rigid polymer with a high degree of crystallinity and a linear structure.

The main distinguishing feature of the products of these brands is strength and density. In addition, they have good resistance to organic and inorganic acids, alkalis, salts and other chemical elements. True, their price is higher.

It should be said that there are PE 32 SDR products, the production of which is regulated by GOST 18599-2001. Most often they are used in the field of water supply systems, with a nominal pressure of no more than 2.5 atmospheres.

The most popular brands and their purpose

At first glance, it may seem that products labeled PE100 are the highest quality and most durable. However, each brand has its own specific purpose. Therefore, next we will consider the most common brands and their purpose.

PE100

A characteristic feature of this brand is:

High working pressure;
Resistance to mechanical stress;
High tensile strength.

Certified raw materials are used for their production. Thanks to the quality characteristics of the material, manufacturers were able to reduce the wall thickness of this product, and, as a result, its weight.

Most often, PE 100 SDR pipe is used:

When installing gas and water pipelines;
When installing pipelines supplying food liquids, for example, milk, juices, wine, etc.

PE80

Features of these products include:

Ease;
Wear resistance;
Good strength.

Medium pressure plastic is used for their production.

Since products of this brand are designed to work under low pressure, they are most often used for the following purposes:

When installing free-flow and low-pressure sewerage systems in apartment buildings.
When installing water supply systems of small diameter located on a small area.

In the photo - PE63 pipes

PE63

This brand of polyethylene is distinguished by the fact that it contains a large number of ethylene molecules.

Therefore, it is characterized by the following properties:

Short term strength;
Tendency to cracking;
Tendency to destruction.

As a result of these shortcomings, it is rarely used in industrial and civil construction. As a rule, products of this brand are used in the construction of drainage systems for foundations, basements and road communications.

In addition, they are used when laying fiber optic lines and electrical cables. Sometimes they are used to organize drainage of moisture from waterlogged areas.

Pipes with different SDR

Products with different SDRs, of course, have different properties, and therefore are used in different areas of construction. Next, we will take a closer look at their features.

Polyethylene grade 100

So, products of the PE 100 brand have the following qualities:

PE100 SDR17 pipe is an indispensable material for the construction of gas pipelines and pressure water supply systems. They are especially in demand where a large cross-section pipeline is required.
It must be said that SDR17 belongs to the new generation of products that are obtained by using modern technologies. As for other features of the PE100 SDR17 pipe – specifications make it possible to use it when constructing long-distance pipelines, which is also an important advantage.
SDR11 - made of low pressure polyethylene. Due to the high density of the material, the products can be used for high-pressure water pipes. In addition, PE 100 SDR 11 pipes are often used in applications, as they are resistant to aggressive environments. Their installation can be carried out in any soil.
PE100 SDR21 – intended for installation of water pipelines. According to experts, the water in such a water supply has no taste, while the PE 100 SDR17 and SDR11 pipes spoil its taste.

Polyethylene grade PE 80

Products of this brand are of the following types:

PE80 SDR17 – is optimal choice for low-rise buildings when installing a water supply system. Such products have good strength and at the same time low cost.
PE80 SDR11 pipe is a new generation product. They are usually used to supply cold water. In addition, they can be used for gasification and sewerage.
PE80 SDR13.6 are used for repair and installation of water pipelines for liquid chemicals.

Polyethylene PE 63

PE63 are manufactured with an SDR value of 11. Various types of polymers are used as materials for them. They can be used both for water supply and for the installation of sewer systems.

In addition, they are often used as a protective case for power supply and communications communications.

Advantages

Finally, let’s consider the advantages of using pipelines of this type:

Wide range of applications	As mentioned above, the products are used in both civil and industrial construction, since they can have very high strength characteristics. An example of this is the PE100 SDR11 pipe.
Durability	The service life of pipelines can be up to 50 years.
Environmental resistance	The products are resistant to rotting, corrosion, do not require cathodic protection, etc.
Light weight	Thanks to this, they are easy to transport. You can install the pipeline yourself.
Frost resistance	The pipeline does not lose its integrity even if the water in it freezes.

Note! The installation instructions for such polyethylene pipelines involve the use of a special soldering iron.

Conclusion

Polyethylene pipes with different SDR values can be used for laying the most different types pipelines. This possibility is explained by a large selection of brands that have certain properties. In addition, their important advantage is the excellent combination of quality and low cost.

You can get more information on this topic from the video in this article.

What does SDR stand for in pipe marking?

SDR is a standard dimensional ratio.

SDR denotes the ratio of the nominal outside diameter of the pipe to the nominal wall thickness. It is part of the marking of polyethylene pipes.

GOST 18599-2001 for pressure pipes made of PE 63, PE 80 and PE 100 defines the following standard dimensional ratios:

- SDR 41

- SDR 33

- SDR 26

- SDR 21

- SDR 17.6

- SDR 17

- SDR 13.6

- SDR 11

- SDR 9

- SDR 7.4

- SDR 6

The SDR index is characterized by inverse proportionality. This means that products with a higher SDR number have fairly thin walls, and pipes with a lower SDR number have thicker walls.

Why is SDR needed?

To select the right polymer pipe for a specific purpose, you need to know its characteristics. This will help you understand how the pipe will behave in specific conditions. For example, what is SDR, what pressure from the inside or outside can it withstand, how will it behave during soil shifts and temperature changes. If the pipe has thick walls, it can be more resistant to internal and external influences. The SDR index allows you to find out the wall thickness and take into account what pressure it can withstand.

Polymer pipes withstand the highest pressure with the indicator SDR 6. The permissible pressure for pipes of this type is 25 atmospheres,

SDR 7.4 - 20 atm,

SDR 9 - 16 atm,

SDR 11 - 12 atm,

SDR 13.6 - 10 atm,

SDR 17 - 8 atm,

SDR 17.6 - 7 atm,

SDR 21 - 6 atm,

SDR 26 - 5 atm.

Pipes with indexes SDR 33 and SDR 41 can withstand pressure up to 4 atmospheres.

Based on these figures, you need to consider which pipes with what SDR rating can be used in the required conditions. For example, products with an SDR index of 6 to 9 are used in pressure systems where there is high pressure: sewers, gas and water mains.

Pipes with SDR from 11 to 17.6 can be used in irrigation or water supply systems with lower pressure. Products with SDR from 21 to 26 can be installed in low-rise buildings for water supply. Pipes with index SDR 33 and SDR 41 are usually used for systems without water pressure (sewer outlets).

When choosing polymer pipes, in addition to the SDR indicator, you also need to take into account the grade of polyethylene that is used in production. Pipes made of a higher grade of polyethylene, all other things being equal, will be stronger, which means they can be more resistant to external and internal influences.

For example, a low-pressure polyethylene (HDPE) pipe made from PE 100 will be more durable than from PE 80, with equal SDR indices. The SDR 17 rating of PE 100 pipes means that such a product can be used for water supply systems or gas pipes with sufficiently high pressure. On the contrary, the same pipes, but made of PE 80, with an SDR index of 17, can only be used in “low-rise buildings” and private houses, where their strength is quite sufficient, and their comparative cheapness will slightly reduce the cost of repair work.

To select the right polyethylene pipes, you need to know what conditions they are intended for, what operating pressure they can withstand, what SDR is and other technical parameters.

The use of polyethylene pipes is more profitable and convenient, in contrast to products made from other materials (metal, metal-polymer, cast iron), since they are: lighter, more durable, do not corrode, smooth inside, and are easy to install and dismantle. It is easier and faster to weld sections of polyethylene pipes than similar metal pipes, and training welders takes less time.

Plastic pipes are also flexible enough to withstand soil pressure, withstand earthquakes, and resist freezing of liquids in them. It is much easier to dispose and recycle polyethylene pipes than metal ones.

If you look at any polyethylene pipe, you can see inscriptions on it that allow you to determine its properties and purpose. For example: name of the manufacturer, type of material from which the pipe is made (grade of polyethylene), GOST, diameter, marking with the SDR index.

What is SDR?

This is one of several main dimensional characteristics of polymer pipes, among which are: Dn, ID, OD, En, as well as SDR. The abbreviation SDR is derived from English words“standard dimension ratio”, denoting the standard ratio of the diameter of a polyethylene pipe (external) to its thickness: SDR = Dn/En.

The SDR index is characterized by inverse proportionality. This means that products with a higher SDR number have fairly thin walls, and pipes with a lower SDR number have thicker walls.

For pipes made of polymer materials, SDR numbers are not arbitrary, but have standardized values, usually from 6 to 41 (6; 7.4; 9; 11; 13.6; 17; 17.6; 21; 26; 33; 41).

Why is SDR needed?

To select the right polymer pipe for a specific purpose, you need to know its characteristics. This will help you understand how the pipe will behave in specific conditions. For example, what is SDR, what pressure from the inside or outside can it withstand, how will it behave during soil shifts and temperature changes. If the pipe has thick walls, it can be more resistant to internal and external influences. The SDR index allows you to find out the wall thickness and take into account what pressure it can withstand.

Polymer pipes with SDR 6 can withstand the highest pressure. The permissible pressure for pipes of this type is 25 atmospheres, SDR 7.4 - 20 atm, SDR 9 - 16 atm, SDR 11 - 12 atm, SDR 13.6 - 10 atm, SDR 17 - 8 atm, SDR 17.6 - 7 atm, SDR 21 - 6 atm, SDR 26 - 5 atm. Pipes with indexes SDR 33 and SDR 41 can withstand pressure up to 4 atmospheres.