What does sdr mean 11. Marking of polyethylene pipes. How to find out the SDR of polyethylene pipes, for which pipes with different indicators are used

When purchasing from the SantekhnikUM company, for the device of communication systems for home or industrial purposes, you can see the marking applied to them with a set of various data about a particular product. It contains:

information about the pipe manufacturer,
numbers of GOST standards, in accordance with which it was manufactured,
the abbreviation "PPR", meaning that the pipes are made of polypropylene - a thermoplastic polymer of the hydrocarbon "polypropylene".
the diameter of the product and the thickness of the material of its walls,
as well as the abbreviation SDR with a specific index.

In this case, the SDR of polypropylene pipes is a strength value that can be used to most accurately determine the capabilities of tubular products.

What makes up SDR

SDR (from English Standard Dimension Ratio - standard dimensional coefficient) is a dimensional characteristic of a polymer pipe, which is the result of the ratio of the outer diameter to the thickness of the polypropylene wall. This value is inversely proportional to the pipe wall thickness, that is, products with a large SDR index have thinner walls, and vice versa - a thick-walled pipe is indicated by a smaller SDR.

Pipes of the same diameter with thicker walls can withstand much greater loads, which are caused during operation by the following technical and natural factors:

internal pressure of the content,
external compressions, for example, when the pipe is covered with earth,
external mechanical influences, such as seasonal ground shifts, etc.

That is, the SDR indicator, along with the thickness of the polypropylene layer, indicates the load or pressure (internal and external) possible for a given pipe.

What is the difference between pipes with different SDR index

General differences

At the moment, polypropylene pipes are produced with SDR from 6 to 41, for which the loads presented in the following table by “pressure classes” are possible:

SDR 6	SDR 7.4	SDR9	SDR 11	SDR 13.6	SDR 17	SDR 17.6	SDR 21	SDR 26	SDR 33	SDR 41
25 atm	20 atm	16 atm	12 atm	10 atm	8 atm	7 atm	6 atm	5 atm	4 atm	4 atm

Thus, the standard dimensional coefficient can be used in determining the purpose of the pipe for specific systems - pressure and non-pressure, namely:

Pipes with the index SDR 26-41 are used for non-pressure (gravity-flowing) sewer outlets;
With indicators of 21-26, they can already be used for intra-house low-pressure water supply of low-rise buildings;
Products indexed by an indicator from 11 to 17 can be used for the construction of low-pressure water supply and irrigation systems;
Pipes with SDRs above less than 9 are suitable for pressure systems designed for water supply, the installation of pressure sewers and even gas pipelines.

Examples

Polypropylene pipes of the same brand with different SDRs can have significant differences. So, for the most popular brand of polypropylene SDR 11 (PN 10) VALFEX

Polypropylene pipe SDR 11 (PN 10) VALFEX– Pipe made of polypropylene PPR-C SDR 11 (PN 10) complies with GOST 32415-2013, suitable for systems of drinking and household cold water supply, hot water supply, as well as process pipelines transporting liquids and gases, non-aggressive to pipe materials. Pipes have good thermal insulation properties, chemical resistance to more than 300 substances and solutions, as well as noise-absorbing properties. Maximum operating temperature: +60 °С. Pipeline installation technology - polyfusion welding.;

Polypropylene pipe SDR 6 (PN 20) VALFEX-Pipe made of polypropylene PPR-C SDR 6 (PN 20) complies with GOST 32415-2013, suitable for systems of drinking and household cold water supply, hot water supply, as well as technological pipelines transporting liquids and gases, non-aggressive to pipe materials. Pipes have good thermal insulation properties, chemical resistance to more than 300 substances and solutions, as well as noise-absorbing properties. Maximum operating temperature: +95 °С, short-term up to +100 °С. Pipeline installation technology - polyfusion welding;

Polypropylene pipe reinforced with fiberglass SDR 7.4 (PN 20) VALFEX- Polypropylene pipe PP-R, reinforced with fiberglass, SDR 7.4 (PN 20), complies with GOST 32415-2013 and is used for radiator heating systems, drinking hot and cold water supply systems, air conditioning, industrial pipeline networks. The pipe has an extended service life in heating and cooling systems, because fiberglass layer provides pipe strength with a smaller wall thickness, while the conductivity of the carrier is increased by 20%. Pipeline installation technology - polyfusion welding. Maximum operating temperature: +95°С.

Polypropylene pipe reinforced with fiberglass SDR 6 (PN 25) VALFEX — Polypropylene pipe PP-R, reinforced with fiberglass, SDR 6 (PN 25), complies with GOST 32415-2013 and is used for radiator heating systems, drinking hot and cold water supply systems, air conditioning, industrial pipeline networks. The pipe has an extended service life in heating and cooling systems, because fiberglass layer provides pipe strength with a smaller wall thickness, while the conductivity of the carrier is increased by 20%. Pipeline installation technology - polyfusion welding. Maximum operating temperature: +95°С.

Polypropylene pipe reinforced with aluminum SDR 6 (PN 25) VALFEX — Pipe polypropylene reinforced with aluminum PP-R PN 25 SDR 6 (PN 25) complies with GOST 32415-2013. It is used in cold, hot water supply, low- and high-temperature heating, when laying pneumatic pipelines, technological pipelines, in integrated fire-fighting water supply systems. The inner aluminum layer has absolute oxygen impermeability, reduces the temperature elongation of the pipeline, and also increases the strength of the pipe, due to the presence of a continuous longitudinal weld. The special design of the pipes does not require stripping before welding. Nominal pressure (transportation of cold water) - 25 bar. The maximum operating temperature is 90 °C. The range of outer diameters of the proposed polypropylene pipes is 20–110 mm.

IMPORTANT! When choosing a pipe according to SDR, be sure to consider the grade of polypropylene from which it is made. Even for the same dimensional coefficients, a pipe of a higher grade will be stronger and more resistant to mechanical stress. For example, SDR 6 (PN 25) VALFEX, Unlike SDR 6 (PN 20) VALFEX with the same index, can be used for pressure water and gas pipelines.

When purchasing polyethylene pipes for arranging communication systems for domestic or industrial purposes, you can see the markings applied to them with a set of various data about a particular product. It contains:

information about the pipe manufacturer,
numbers of GOST standards, in accordance with which it was manufactured,
the abbreviation "PE", meaning that the pipes are made of polyethylene - a thermoplastic polymer of the hydrocarbon "ethylene", and its brand (PE-100, PE-80, etc.),
the diameter of the product and the thickness of the material of its walls,
as well as the abbreviation SDR with a specific index.

In this case, the SDR of polyethylene pipes is a strength value that can be used to most accurately determine the capabilities of pipe products.

What makes up SDR

SDR (from English Standard Dimension Ratio - standard dimensional coefficient) is a dimensional characteristic of a polymer pipe, which is the result of the ratio of the outer diameter to the thickness of the polyethylene wall. This value is inversely proportional to the pipe wall thickness, that is, products with a large SDR index have thinner walls, and vice versa - a thick-walled pipe is indicated by a smaller SDR.

Pipes of the same diameter with thicker walls can withstand much greater loads, which are caused during operation by the following technical and natural factors:

internal pressure of the content,
external compressions, for example, when the pipe is covered with earth,
external mechanical influences, such as seasonal ground shifts, etc.

That is, the SDR indicator, along with the thickness of the polyethylene layer, indicates the load or pressure possible for a given pipe, or pressure (internal and external).

What is the difference between pipes with different SDR index

General differences

At the moment, polyethylene pipes with SDR from 6 to 41 are produced, for which the loads presented in the following table by “pressure classes” are possible:

SDR 6	SDR 7.4	SDR9	SDR 11	SDR 13.6	SDR 17	SDR 17.6	SDR 21	SDR 26	SDR 33	SDR 41
25 atm	20 atm	16 atm	12 atm	10 atm	8 atm	7 atm	6 atm	5 atm	4 atm	4 atm

Thus, the standard dimensional coefficient can be used in determining the purpose of the pipe for specific systems - pressure and non-pressure, namely:

Pipes with the index SDR 26-41 are used for non-pressure (gravity-flowing) sewer outlets;
With indicators of 21-26, they can already be used for intra-house low-pressure water supply of low-rise buildings;
Products indexed by an indicator from 11 to 17 can be used for the construction of low-pressure water supply and irrigation systems;
Pipes with SDRs above less than 9 are suitable for pressure systems designed for water supply, the installation of pressure sewers and even gas pipelines.

Examples

Polyethylene pipes of the same brand with different SDRs can have significant differences. So, for the most popular brand of polyethylene PE-80, this is:

PE 80 SDR 13.6 - very durable, can be used for the construction of long-term water supply systems;
PE 80 SDR 17 are considered products with average performance and are recommended for installation in plumbing systems of low-rise buildings, where their strength is quite sufficient, and low weight and low cost will save on installation work;
PE 80 SDR 21 is not recommended for pressurized systems, buried in the ground and gas pipelines, as they have low compressive strength and internal pressure.

IMPORTANT! When choosing a pipe according to SDR, be sure to consider the grade of polyethylene from which it is made. Even for the same dimensional coefficients, a pipe of a higher grade will be stronger and more resistant to mechanical stress. For example, PE 100 SDR 17, unlike PE 80 with the same index, can be used for pressure water and gas pipelines.

Standard dimensional ratio or Standard Dimension Ratio, the combination that gave rise to this abbreviation. We are talking about SDR for polyethylene pipes, and the simplest formula for its definition is:

Where dn is the outer diameter, en is the pipe wall thickness. So, we understand that the thinner the pipe, the more SDR and vice versa. In fact, it is possible to calculate just the wall thickness through the SDR indicated in the marking, because this indicator is standard: 41, 33, 26, 21, 17.6 and below, up to 9 - all these are SDRs of pipes of different thicknesses. In addition, the standard dimensional ratio depends on another indicator, namely, the pipe series:

SDR 41

SDR 33

SDR 26

SDR 21

SDR 17.6

SDR 17

SDR 13.6

SDR 11

SDR9

SDR 7.4

SDR 6

where S is the series.

What is a series?

For domestic pipes produced in accordance with GOST 8032 and foreign pipes corresponding to it, S is a normalized value and depends on the size of the product. It will help to determine how many times the stress in the pipe wall from the applied working pressure MOP exceeds this working pressure. For example, series 2.5 says - two and a half times the allowable voltage is higher than the MOP.

The maximum working pressure itself, at which (in a constant value) the service life of the pipe reaches the 50 or 100 years declared by the manufacturer, is calculated as follows:

MOP=2 MRS/

Where MRS is the minimum strength of PE in long-term operation, and C is the safety factor. We are already familiar with SDR. C can take values of 1.25 (for cold pipes), 2 or 3.15 for hot pipes or transporting explosive gases. When choosing a series, they don’t pay much attention. It is enough to select pipes according to MRS and SDR, if the operating conditions are already known.

Published: September 22, 2015

Any pipes have a certain marking system. We propose to consider what SDR pipes are, why they are needed and what is the peculiarity of using these building materials.

Marking of polyethylene pipes

SDR is a unique pipe designation system that defines the ratio of the outer dimension of the service to the wall thickness. Accordingly, the smaller this indicator, the thicker the pipe and vice versa. In this case, most often the designation SDR is used in relation to polyethylene pipes. In this case, a 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:

Now the most commonly used polyethylene pipes SDR, made of plastic type 80 and 100. Each of the brands has its own characteristics:

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

The installation of pipes of the SDR series is carried out in the same way as standard polyethylene materials - using a welding machine or an electric coupling, but due to the density of the molecules, the seam is more dense and airtight.

Peculiarities

In order to better navigate the products of the SDR type, 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 of a private house. They do not tolerate temperature extremes, they 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 of a running meter is from 25 rubles.

HDPE PE-63 SDR 17.6 made in accordance with GOST 18599-2001 (2003) - these are water supply pipes that are used in systems at a pressure of not 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, because pipes have a rather high coefficient of deformation - they can be deformed from high temperatures.

PE 80 SDR 13.6 is the best option for home plumbing. They do not tolerate temperature extremes, they are used at home. If necessary, you can equip the external water supply with communications, 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 thickness of the walls allows the use of materials in a wide variety of industries, from home production to industrial water supply.

PE 100 SDR 11 is the most dense pipes of this series, made of polyethylene grade 100. They perfectly tolerate any load of the heating, sewerage 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. Basically, communications are 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 grade 100 polyethylene. Basically, these are 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 pipe 100 SDR 17

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 pipes of the PE 100 SDR 17 series:

Water supply;
Private production;
Drainage.

PE 100 SDR 21 is especially popular with many home craftsmen. These are unique polyethylene pipes that do not give the liquid passing through them the characteristic smell of plastic. Due to 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 density of adhesion of polyethylene molecules and the optimal ratio of diameters to wall thickness make it possible to provide with the help of these communications a strong and tight fastening even when using pipes of different types. Professional plumbers recommend combining this particular brand with steel communications.

Application area:

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

PE 100 SDR 26 are reliable and durable communication materials. Thin walls will allow you to successfully use pipes 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, while you do not have to worry about their strength. The SDR 26 grade is made from low-pressure polyethylene, which makes it resistant to temperature and pressure fluctuations inside the drainage or heating system.

Scope of SDR 26:

Winemaking and other home production;
Water supply cold and hot;
Heating at a coolant temperature of not 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 pipe SDR PE 100:

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

There is also a separate type of SDR pipes, which are reinforced with a sealant, for example, this is the 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). At the same time, each layer of plastic is also reinforced with a special reinforcing substance, most often it is a thermofiber. Such pipes not only have excellent rigidity, but also resist temperature extremes and freezing of water in them. They are used for arranging street sewerage, external water supply or a shallow drainage system.

Advantages of the PRO AQUA SDR series:

Durability over 50 years;
The material is resistant 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 hermetic fastening;
PRO pipes are known for their low linear expansion, i.e. even with a strong temperature difference, they do not deform.

Polyethylene pipe 100 sdr is a standard marking that everyone who works with polyethylene pipes encounters from time to time, ensuring their installation and selection at each specific facility.

So that such a designation does not surprise you, and you can freely choose samples based directly on the SDR factor, let's figure out what this characteristic is, what exactly it means, and what the client needs to know about its use in each specific situation.

Article content

general characteristics

Sdr is the strength characteristic of a polyethylene pipe (in abbreviated form, these products are referred to as pnd), which can be used for the construction of water pipes, work lines at a food industry enterprise, as well as gas pipelines.

It indicates the ratio of the outer diameter to the wall thickness. The higher this indicator, the thinner the pipe wall, respectively, and vice versa, if we are talking about samples having the same nominal diameter. The parameter is standardized for almost all types of pipes.

However, a small error in this parameter is allowed, which may be caused by the technical conditions for the production of a particular pipe, however, as a rule, this does not affect the performance of products.

Let's give an example: if we have two pipes with an indicator of 21 and 11 according to the SDR, however, with a total diameter, the one that has such a designation 11 will be stronger than 21. Accordingly, if we are talking about which one is better to install in a system with increased operational loads, it would be better to choose, accordingly, a product marked 11, and not 21.

It would be advisable to follow this rule also if it is selected or for working with other types of liquids. The use of certain pipes, as well as their main characteristics, are indicated in GOST 8032, which regulates the standards for these products.

Basic indicators

This indicator can range from 40 to 6, depending on the type of pipe, as well as its purpose. Often there are samples 17, 21, 11. Often, models 17, as well as sdr11, are chosen for a wide range of work.

The second most common marking for such pipes is the designation PE. She just points to the brand of polyethylene.

Most often, you can find on sale samples marked PE 63, 80, PE100, 160 and higher. Let's take a closer look at the following key differences:

A material with a lower index needs a lower soldering temperature.
Polyethylene 100 samples have a slightly different material structure, more ordered than in the version with a lower indicator, which makes it possible to obtain a more even seam during processing of the material.
Sample 100 is generally stronger, respectively, it can be used under various operating conditions, including the heaviest ones.
The production cost of samples with the 80 mark is higher than those with a higher value, since they usually require more material to produce.

Similar patterns in the ratio of production costs, as well as the characteristics of material processing, apply to models with an indicator of 63, 160, which in recent years has also been bought for some home networks.

Technical characteristics of HDPE pipes (video)

Description of the most common types of pipes with different parameters

Currently, you can find on the market such samples with the most common indicators:

80 SDR 21 - HDPE polyethylene, designed for arranging sewerage in apartment buildings. They can be used specifically in non-pressure water supply systems, in some cases low-pressure in open areas, although for them it is more often recommended to take samples that have the first such designation 160. Samples with parameters 80 and 21 are not intended for gas transmission, as well as installations in highways.
PND 80 SDR 17 is one of the universal versions of the pipe, like samples 160, the technical characteristics of which allow it to be installed in irrigation systems, sewers, as well as cold water supply systems. It may well be suitable for low-rise construction. Please note that the sdr17 version in this case can only be used in those water pipes where preliminary water treatment is carried out.
PND 80 SDR 13.6 - samples developed directly for water pipes through which drinking water is transported. Produced from an improved version of polyethylene of a given thickness.
Polyethylene samples with parameters 100 and 26. The best types of pipes specifically for drinking water, as well as other types of food liquids. They have a low wall thickness like the 160 models, but thanks to the use of a new type of polyethylene, they are quite durable. In addition to pipelines, they can also be used to ensure the supply of food materials directly to food production.
Polyethylene pipes with parameters 100 and 21. A special type of models, the technical characteristics of which make it possible to transport drinking water through them absolutely without losing its taste. Can be used together with steel counterparts.
PND models marked 100 and 17, respectively. These are polyethylene samples with SDR 17 with an increased level of strength, which can be used not only for pressure water pipelines, but even for gas transportation. By the way, it is they (SDR 17) that can be used to create systems of a rather large length.
Samples of polyethylene pipes 100 by 11. The features of just this brand of pipes are precisely the high density of the material obtained in the manufacture of pipes under low pressure. Suitable for particularly wide types of pipelines. Resistant to mechanical as well as chemical influences, in addition, models with SDR 11 can be laid in any type of soil.

Samples marked 63 and various types of SDRs, respectively, can also be used to organize pressurized water supply systems. However, their use is more limited.

It should be noted that pipes with the indicated markings, although must comply with uniform standards for such systems, in fact, the level of quality may vary slightly. This is due to the technical conditions for the production of various models of pipes.

They must be taken into account when ordering samples directly from the markings.