Nominal pressure pn 16. What is nominal diameter DN and nominal pressure PN

Polypropylene pipes came into use relatively recently - in the 60s of the 20th century. Their wide range of operation is explained by their high strength, lightness, ease of installation, and ease of installation of fittings.

Polypropylene pipes - area of ​​application

• transportation of chemically active liquids. Polypropylene is a completely inert material;
• gas supply under pressure. Polypropylene can withstand pressure up to 25 atmospheres. For the same reason it is used for pneumatic technologies;
• as an irrigation, supply of atomized water;
• in the water supply of hot and cold liquids;

What is polypropylene

It is an organic synthetic polymer - thermoplastic and non-polar. In 1957 this material began to polymerize using a Ziegler-Natta catalyst, and launched its industrial production.

Although the material is plastic under the influence high values temperatures, but in its normal state it has high strength, is chemically inactive, practically does not absorb moisture, and does not transmit electricity. It is suitable for distilling food liquids.

The main advantages of polypropylene pipes:

1. practically do not corrode;
2. excellent resistance to mechanical and bioactive influences;
3. practically do not create noise and vibration;
4. fittings can be installed easily and into any part of this material;
5. almost absolute safety for human life and health;
6. heat resistance and low heat loss during transmission hot water;
7. service life, which is several times greater than the service life of steel alloy pipes;
8. ease.

Polypropylene pipes marking

1. Single layer. Brands:

– P.P.H. Made from homopropylene. Used in industry, for arranging ventilation and transmission cold water;

– P.P.B. Made from block copolymer. They are used for laying pipelines that must withstand high pressure and external forces - underfloor heating, water supply under high pressure;

– PPR. Made from random copolymer. The main feature is uniform load distribution. They are used in underfloor heating and water supply installations. Protection from the sun (UV rays) is required if used outdoors;

– P.P.S.. They are resistant to fire. Working temperature– no higher than 95 degrees. Used in fire hazardous conditions.

2. Multilayer. They have increased strength and a reduced coefficient of thermal expansion when compared with their single-layer counterparts. They can be reinforced with aluminum foil and, accordingly, smooth or perforated. Fiberglass reinforcement is also possible. Brands:

– PN10. The number in the marking after the letters means the maximum operating pressure. Operating temperature – 45 degrees;

– PN16. Operating temperature – 60 degrees. Used for arranging cold water supply with high pressure;

– PN20. Operating temperature – 95 degrees. Used for installation of heating systems, including centralized ones;

– PN25. Operating temperature – 95 degrees. They are used for installation of heating systems, floor heating and hot water supply.

Polypropylene pipes are firmly established in the water supply system. The water supply is the primary communication system with which the improvement of any home begins, be it an apartment or a country house. After all, without water, neither sewerage, nor heating, nor water intake household appliances will be able to function.

Today, domestic manufacturers produce a wide range of pipeline products, which differ in both technical parameters, and cost. Knowing what classification is and which polypropylene heating pipes can be used in residential premises becomes an indispensable tool for a modern designer.

Polypropylene pipes for heating and water supply differ from their steel counterparts at an affordable price, light weight, high resistance to corrosion and external influences, therefore they are widely used for domestic and industrial water supply. Every year, the number of households who connect the heating of their home with polypropylene pipes is growing.

Polypropylene pipes, classification and marking

Polymer products are produced and labeled based on operating conditions:

• PN 10– produced for cold water supply with a liquid temperature of no more than + 20˚С;
• PN 16– also designed for cold water, but with increased pressure;
• PN 20– universal pipes for hot (up to + 80˚С) and cold water supply;
• PN 25– are produced with reinforcement with fiberglass, aluminum or an additional layer of polymer. They are characterized by high tensile strength and a minimal coefficient of thermal expansion. This brand is purchased when polypropylene pipes for heating are needed.

To marking polymer pipes includes other letter designations that indicate the presence of plasticizers and additives that determine specifications and properties of polypropylene:

• RRN– homopolymer of polypropylene. Designed for cold water supply and ventilation systems, because it is not able to withstand high temperatures;
• RRV– polypropylene block copolymer with polyethylene content up to 30%. Possesses significant flexibility, resistance to low and high temperatures;
• PPR– static (random) polypropylene copolymer with a crystalline molecular structure. It is not afraid of water hammer, high temperatures and pressure in the main line. In addition to water supply, they are used when installing water heating and heated floors;
• PPs– fire-resistant and high-strength type of polypropylene with fire retardant. It differs from other types of polymers in its high maximum permissible temperature (95˚C).

Polypropylene pipes for water supply - advantages

Manufacturers polypropylene pipes provide a guarantee for their products for more than 50 years, since this material has been widely used on an industrial scale since 1960, while many pipelines are still in stable use.

Thanks to the unique production technology, polypropylene pipes have a high threshold of heat resistance and strength, withstanding pressure in the main line up to 10-20 atmospheres.

Polypropylene pipes for water supply are not afraid of exposure to aggressive reagents and significant temperature changes; even when freezing and thawing, they do not lose their integrity.

– simple installation that does not require special skills and specialized specialization. To install a water supply, you will need additional components (fittings, shut-off and control valves), as well as special equipment for heating and welding polypropylene.

We invite you to familiarize yourself with the best way to choose polypropylene pipes for water supply. Figure out which ones are better, which pipe is intended for what. Let's watch the video review.

Polypropylene pipes for a reliable water supply system

Traditional steel pipes are practically no longer installed in modern residential buildings. They have been replaced by more reliable technologies using polypropylene pipes, which ensure high tightness in hot and cold water supply systems.

Polypropylene pipes are easy to install, do not rust, withstand high water pressure and water hammer, are light weight and affordable.

For the manufacture of polypropylene pipes it is used environmentally safe type plastic that does not contain degradable components. Pipes are classified depending on the scope of application into products intended for cold water, hot water and drinking water.

There are quite a lot of similar products on the market, differing in diameter, plastic thickness, and the presence or absence of a reinforced layer. To select suitable pipes for each specific case, it is necessary to consult with specialists.

Advantages of polypropylene pipe products:

- absence harmful substances;
– no deposits appear inside;
– not subject to corrosion;
– the connections are sealed;
– no need for coloring;
– ease of installation;
– low cost;
– can be used to supply drinking water;
– service life exceeds 50 years;
– resistance to mechanical stress;
– good flexibility;
– light weight.

Disadvantage plastic pipes from polypropylene is that they elongate significantly as a result of thermal expansion of the material. To solve this problem, manufacturers suggest using reinforced pipes in hot water supply systems.

Fiberglass or aluminum foil is used as a reinforcing layer. Fiberglass reduces the thermal elongation rate by several times, so the pipes retain their dimensions even under high heat.

There is no need to use reinforced pipes in cold water supply systems. In this case, you can install simple polypropylene products, which provides significant savings and makes the installation process easier.

The difference between the pipes, glass fiber reinforced, and pipes with an aluminum layer is that the former are more convenient to install. When pipes with an aluminum reinforcing layer are installed, the foil makes the cutting process difficult. When cutting pipes, you need to get a neat end, and due to the presence of foil, this is much more difficult to do.

Installation of polypropylene pipes

When installing polypropylene pipes, traditional metal welding is not used, so sparks do not fly in the room, which increases the safety of the work. Pipe connections are made using a special device that melts the plastic at the very end of the pipe, allowing you to create a monolithic and completely sealed connection. In this case, you can do without rubber gaskets and all kinds of seals.

Polypropylene pipes are significantly superior to steel products in terms of ease of installation, system reliability, as well as decorative and performance indicators. Unlike steel pipes, plastic ones are not prone to vibration. To their inner surface solid particles do not stick, which eliminates the problem of reducing diameter and reducing throughput.

Polypropylene pipes are equally well suited for creating durable and sealed water supply systems in apartment buildings, country houses and cottages.

The economic benefit of their use is that they are affordable, do not require much effort during transportation, are very quick and easy to install, and last for many decades without requiring expensive repairs. Thanks to the high-quality installation of such pipes, the likelihood of flooding your home and your neighbors’ apartment is much lower than when using conventional metal pipes.

Industrial pipeline fittings are the name of a number of devices intended for installation on units, vessels or pipelines. The main operational task of pipeline fittings is to control (distribution, shutdown, discharge, regulation, etc.) flows of gaseous, powdery, liquid, gas-liquid working media by increasing or decreasing the flow area.

Traditionally distinguished two main operational parameters pipeline fittings: nominal size(nominal diameter) and nominal (nominal) pressure.

Conditional bore (DN or DN) is a parameter by which the connecting elements of a pipeline are characterized: the nominal bore (nominal size of the fittings) is expressed in millimeters and is approximately equal to the internal diameter area of ​​the connected element.

* Suitable for use with hydraulic and pneumatic devices.
** Not allowed for general purpose fittings.

Nominal (conditional) pressure (PN or PN) – maximum excess pressure in the system at a working medium temperature of 20° C, which allows to ensure the operational service life of individual elements connecting fittings and pipeline. Designations and values ​​of conditional pressure must correspond to the ratings specified in GOST 26349-84.

The choice of nominal pressures less than 0.01 MPa is carried out from the R5 series, more than 100 MPa - from the R20 series (according to GOST 8032-84).

When marking pipeline fittings, the design of which was developed before 01/01/1992, the use of the nominal pressure designation Ru is allowed. The designation of conditional pressure PN6 can be used instead of the designation PN 6.3.

Operating pressure Pр – maximum excess pressure at operating temperatures that ensure the specified operating mode of pipeline fittings.

Test pressure Ррр – excess pressure at which it is possible to carry out hydraulic tests of pipeline fittings and connecting elements for tightness and strength. Test pressure values ​​are determined in accordance with GOST 356-80. If the operating pressure value is below 20 MPa, then the test pressure will be approximately 1.5 times higher than Pр.

The classification of industrial pipeline fittings is carried out taking into account several technical, functional and operational characteristics.

Application area

Depending on the area and scope of application, the following types of industrial pipeline fittings are distinguished: general purpose pipeline fittings, fittings for special operating conditions, special fittings, transport and ship fittings, sanitary fittings.

1. General purpose pipeline fittings It is mass-produced and designed for use in all areas and industries.
2. Pipe fittings for special operating conditions intended for use in energy systems having high technological characteristics. In addition, industrial fittings of this type used in the installation of pipelines used to transport highly toxic and aggressive working media.
3. Development and production special fittings carried out, as a rule, on special orders from individual departments or state enterprises. Scope of application of special fittings – ships power plants, objects of the Ministry of Defense, nuclear power plants and so on.
4. Transport and ship fittings produced for use in the transport industry and, in particular, used in shipbuilding. The fittings of this class are subject to increased technical requirements: in the production of transport fittings, the dimensions, weight of products, the possibility of using the fittings in various climatic zones and other characteristics.
5. Plumbing fittings used to complete and organize functionality various types household equipment. Fittings of this type, as a rule, have a small diameter and do not cause any difficulties during operation. The production and release of sanitary fittings is carried out on production lines. In the production of sanitary fittings Special attention traditionally focused on consumer performance and, in particular, product design.

Functional purpose

Depending on the functional purpose The following types of industrial pipeline valves are distinguished: shut-off, control, distribution and mixing, safety, protective and phase separating.

1. Functional purpose shut-off valves– complete opening or blocking of flow in the pipeline. The operation of shut-off valves is determined by technological requirements.
2. Pipeline control type fittings used to regulate the parameters of working media by changing the flow rate. Control valves are various models pressure regulators, liquid level regulators, throttling valves, control valves, etc.
3. The main purpose separation and mixing valves(valves, taps) – mixing flows of the working medium, redirecting flows in the required direction.
4. Safety fittings used for automatic protection of pipelines and equipment from overpressure. When operating safety valves, emergency situations are prevented by discharging excess working fluid from the system. The most common types of safety valves are impulse safety devices, safety valves, bypass valves, diaphragm bursting devices.
5. Functional purpose protective fittings(disconnecting and check valves) – automatic protection pipelines and equipment from failures in technological process due to changes in the parameters of working media, changes in the direction of flows. When operating protective valves, emergency situations are prevented without the release of excess working fluid from the system.
6. Phase separating pipeline fittings are used when it is necessary to organize automatic separation of working environments, taking into account their current state and phase. The most common types of phase separation valves are gas separators, condensate traps, air separators and oil separators.

Construction types

Depending on the design features The following types of industrial pipeline fittings are distinguished: gate valves, valves (gates), taps, gates.

1. Gate valve– a structural type of pipeline fittings, the movement of the working element of which is perpendicular to the direction of flow of the working medium. As a rule, valves are most often used as shut-off pipeline valves.
2. Valve– a structural type of industrial valves, the movement of the control or shut-off element of which is carried out parallel to the axis of the flow of the working medium. There is a variety of this type of fittings - diaphragm valves. In the design of a diaphragm valve, the role of a shut-off element is a membrane, which is fixed between the body and the cover along the outer perimeter and serves as a seal for the shut-off element, body parts and moving elements relative to the external environment.
3. Tap– a structural type of industrial pipeline fittings, the regulating or shut-off element of which has the shape of a body of rotation (or part of it), rotates around its axis and is located arbitrarily in relation to the direction of flow.
4. Gate– a structural type of pipeline fittings, the regulating or shut-off element of which has the shape of a disk and rotates around a non-its own axis.

Conditional pressure of the working medium

• Vacuum fittings (working medium pressure below 0.1 MPa abs.)
• Low pressure (0-1.5 MPa)
• Medium pressure fittings (1.5-10 MPa)
• High pressure (10-80 MPa)
• Ultra-high pressure pipeline fittings (80 or more MPa)

Method of connection to the pipeline

Depending on the method of fastening to the pipeline, the following types of industrial fittings are distinguished: coupling, nipple, welding fittings, clamping, pin, flange, fitting.

1. Accession coupling industrial fittings to the pipeline is carried out using couplings having internal thread.
2. Accession nipple fittings to the pipeline is done using a nipple.
3. Accession pipeline fittings intended for welding, is carried out by welding. This method of connecting fittings to a pipeline has both advantages and obvious disadvantages. In particular, high-quality welding of fittings guarantees absolute tightness of the connection, does not require maintenance (tightening of flange connections), however, it can cause certain problems when carrying out repair work, work on replacing reinforcement elements.
4. Fastening tie rods to the pipeline is done using nuts and studs.
5. .Joining flanged fittings to the pipeline is done using flanges. This method fastening also has advantages (the possibility of repeated installation and dismantling of fittings, high strength, the ability to operate under a wide range of operating pressures and passages) and disadvantages (possible loosening of the fastening, loss of tightness of the connection, large weight and dimensions).
6. Installation pin fittings to the pipeline is carried out at external thread with a collar for sealing.
7. Union fittings attached to the pipeline using fittings.

Sealing method

Depending on the sealing method, the following types of industrial pipeline fittings are distinguished: membrane, bellows, stuffing box.

1. With help membrane fittings The housing elements and movable connecting elements are sealed relative to the external environment. In addition, the membrane fittings make it possible to ensure a seal in the valve.
2. Gland fittings allows for sealing of the spindle or rod relative to the external environment: the sealing of the connection is carried out using an stuffing box that is in direct contact with the movable spindle or rod.
3. Bellows fittings used to seal moving parts (spindle, rod) relative to the external environment. A bellows, which is a power or sensitive element of the structure, is used as a seal.

Control method

Depending on the control method, the following types of industrial pipeline valves are distinguished: drive valves, valves with remote, automatic and remote control.

1. main feature fittings intended for remote control, - absence of a control body. The connection to the control is made using transition elements (columns, rods, etc.).
2. Control driven pipeline fittings carried out using a drive (remotely or directly).
3. Control industrial pipeline fittings designed for automatic control, is carried out without operator participation. Automatic control is ensured due to the direct influence of the working environment on the power or sensitive element, or with the help of signals supplied to the drive from instruments and devices of the automated control system.
4. Control manual valves carried out using an operator.

According to GOST 9544-93, for all types of shut-off valves (except for special valves and valves with electric drive), the following classes of tightness of connections are established at a nominal pressure of 0.1 MPa or more.

Table of minimum duration of hydraulic mash tests:

Table of dependence of media values ​​and pressures for hydraulic tests on nominal (conditional) pressures and diameters:

The choice of medium for hydraulic testing is carried out depending on the functional purpose of the pipeline fittings and compliance with GOST requirements (water - GOST P 51232-98, air - class 0 GOST 17433-80). When conducting hydraulic tests, the temperature of the test medium must be less than 5° C, but not more than 40° C. Permissible error when measuring leaks: ±0.01 cm³/min. for leaks less than 0.1 cm³/min. and ±5% for leaks more than 0.1 cm³/min.

Symbol of fittings according to the TsKBA classification (table-figure)

Classifications of industrial pipeline fittings (TsKBA classification) are made on the basis of accepted symbols, consisting of letters and numbers. The first two digits in the product labeling indicate the type of industrial fittings (see Table 1). The letter (or combination of letters) after the first two digits indicates what material the product body is made of (see Table 2). The letters (or combination of letters) are followed by one or two numbers indicating the model number. If three digits are indicated after the letter designation, then the first is the type of drive (see Table 3), and the next two digits are the model number. The last letters in the marking indicate the material from which the sealing surfaces are made (see Table 4) or indicate the method by which inner covering product body (see Table 5). Reinforcement made without welded or insert rings is designated “bk”.

Table 1

table 2

Table 3

Table 4

Table 5

In parallel with the TsKBA classification system, a system of codes obtained by abbreviating the factory name of products is often used to classify industrial fittings. For example, to indicate ball valve, having a nominal pressure of 16 kg/cm³ and a nominal bore of 15 mm, the designation KSh-16/15 is used. To designate some types of reinforcement structures, only the number of the drawing documentation according to which they were manufactured is used. Often, when classifying products, a letter is indicated indicating the name of the manufacturing plant.

To classify valves intended for use in industries such as oil refining and oil production, a symbol consisting of numbers and letters is also used. If the letters indicate the type of fittings, then the digital value indicates the operational parameters of the product. For example, a cast wedge valve of the 2nd modification, having a nominal pressure of 16 kg/cm³ and a nominal diameter of 200 mm, is designated as ZKL2-200-16.

To designate the working environment in catalogs of industrial pipeline fittings, it is customary to use abbreviations (see Table 6).

Table 6

Selection of shut-off valves for gas distribution systems

When choosing pipeline shut-off valves intended for use in gas distribution systems, you must be guided by the following provisions and regulatory documents: PB 12-529-03, SNiP 42-01-2002 and SP 42-101-2003. In gas supply networks with pressures up to 1.6 MPa, it is recommended (depending on operating conditions) to use the types of pipeline fittings indicated in the table:

When installing pipeline fittings on external gas pipelines in areas with cold climatic conditions, it is necessary to use products in climatic version UHL1, UHL2, HL1, HL2. When conducting installation work pipeline fittings on internal gas pipelines in heated rooms, it is necessary to select products in climatic modifications U1, U2, U3, U5, UHL4, UHL5, KHL5, and for unheated rooms it is recommended to use UHL3, KHL3 (according to GOST 15150-69).

When installing pipeline fittings on internal (in unheated rooms) and external gas pipelines in areas with a moderately cold climate, it is necessary to select products in the climatic version U1, U2, U3, UHL1, UHL2, UHL3 (according to GOST 15150-69).

Select pipeline fittings for external and internal gas pipelines in unheated rooms, taking into account the operating pressure in the system, climatic conditions, housing material, recommended based on the data given in the table:

Carbon steel

* Production of valve body parts must be carried out from the following materials: stamped and forged products - deformable alloy grade D-16 (alloy D-1 can be used), cast products - guaranteed quality with mechanical properties not lower than AK grade - 7ch (AL-9) (according to GOST 1583-93).

As the design operating temperature of the fittings and the temperature of the working medium, it is customary to choose the temperature that is most cold week security 0.92 (according to SNiP 23-01-99).

The hermetic tightness of the valves and gate valves with a nominal bore up to 80 mm must correspond to class B. If there is a nominal bore above 80 mm, it must correspond to class C (according to GOST 9544-93).

The hermetic tightness of the valve of tension cone valves with a nominal pressure of up to 0.1 MPa, which are not covered by GOST 9544-93, must comply with the class standards for a working pressure of 0.1 MPa (according to GOST 9544-93).

The hermetic tightness of valve closures, which are installed on gas pipelines of the liquid phase of LPG, must correspond to class A. When installing valve closures on other types of gas pipelines, compliance with class B (according to GOST 9544-93).

Industrial pipeline fittings used in gas supply systems must have a passport that states that the working medium for this product is liquefied or natural gas.

In a number of cases (subject to compliance with the requirements for the tightness of products; provided that the sealing materials of the valve and body connectors are resistant to the transported gas), the operation of valves intended for natural or liquefied gas, possible for steam, water and ammonia.

The choice of operating and conditional pressure of shut-off valves is carried out depending on the operating pressure parameters in the system and must correspond to the data specified in the following table:

According to the requirements of GOST 4666-75, all types of pipeline shut-off valves must be marked and distinctively painted. The marking is applied to the product body and must contain the manufacturer’s trademark, operating or nominal pressure, nominal diameter and, if necessary, an indication of the direction of flow of the working fluid. The cover and body of the shut-off valves are painted depending on the material.

The electric drive of the shut-off valves must be manufactured in an explosion-proof design.

Tsugunov Anton Valerievich

Reading time: 5 minutes

It is no coincidence that polypropylene pipelines are becoming increasingly popular among home craftsmen and professional installers. Polypropylene pipes have a number of advantages, thanks to which they are gradually replacing products from traditional materials. The choice of plastic pipes today is simply huge and all products differ in their characteristics and purpose. Deciphering the markings of polypropylene pipes will help you find out which of them are suitable for the heating system, cold or hot water supply, and ventilation.

“Reading” the information

• The first place is usually the name of the manufacturer.
• Next comes the designation of the type of material from which the product is made: PPH, PPR, PPB.
• Pipe products must indicate the operating pressure, which is designated by two letters - PN - and numbers - 10, 16, 20, 25.
• Several numbers indicate the diameter of the product and the wall thickness in millimeters.

• On domestic modifications, the operating class may be indicated according to GOST.
• Maximum allowed.

Additionally indicated:

1. Regulatory documents in accordance with which pipe products are manufactured, international regulations.
2. Quality mark.
3. Information about the technology used to make the product and MRS classification (minimum long-term strength).
4. 15 digits containing information about the production date, batch number, etc. (the last 2 are the year of manufacture).

Now let's take a closer look at the most important characteristics polypropylene pipes specified in the marking.

Material and application

Manufacturers from different countries use slightly different designations, but the PP marking will certainly be present, demonstrating that the pipe is made of polypropylene. Additional letters or numbers indicate a specific type of this material, which has its own properties.

1. РРН (РР-type 1, РР-1) – the pipe is made of homopolymer. Due to the characteristics of this type of polypropylene, it is intended only for cold water, as well as for ventilation.
2. RRV (PP-type 2, PP-2) – the product is made of block copolymer. Can be used for cold water supply and low-temperature types of heating systems.
3. PPR (PP-2, PPR, PP-random, PPRC) - the pipe is made of random copolymer. Products with this marking are the most common due to their versatility. Due to increased heat resistance, they can be used in heating systems of any type, as well as for supplying hot and cold water to apartments and houses.

Nominal pressure

The letters PN indicate the permitted operating pressure. The following number indicates the level of internal pressure in bars that the product can withstand over a service life of 50 years at a water temperature of 20 degrees. This indicator directly depends on the wall thickness of the product.

• PN10. This designation is given to an inexpensive thin-walled pipe, the nominal pressure of which is 10 bar. The maximum temperature it can withstand is 45 degrees. This product is used for pumping cold water and installing heated floors.

• PN16.Higher nominal pressure, higher maximum liquid temperature - 60 degrees Celsius. Such a pipe is significantly deformed under the influence of strong heat, and therefore is not suitable for use in heating systems and for supplying hot liquid. Its purpose is cold water supply.

• PN20. A polypropylene pipe of this brand can withstand pressures of 20 bar and temperatures up to 75 degrees Celsius. It is quite versatile and is used to supply hot and cold water, but should not be used in a heating system, since it has a high coefficient of deformation under the influence of heat. At a temperature of 60 degrees, a 5 m section of such a pipeline lengthens by almost 5 cm.

• PN25. This product has a fundamental difference from previous types, because it is made of fiberglass. The properties of a reinforced pipe are similar to metal-plastic products, it is less susceptible to temperature effects, and can withstand temperatures of 95 degrees. Designed for use in heating systems, as well as in hot water supply.

Service class

When choosing domestically produced polypropylene products, the purpose of the pipe will indicate the service class according to GOST.

• Class 1 – the product is intended for hot water supply at a temperature of 60 °C.
• Class 2 – DHW at 70 °C.
• Class 3 – for underfloor heating using low temperatures up to 60 °C.
• Class 4 – for floor and radiator heating systems that use water up to 70 °C.
• Class 5 – for radiator heating with high temperatures – up to 90 °C.
• CW – cold water supply.

HELPFUL INFORMATION: Which water filter to choose for an apartment

Dimensions

The sizes of polypropylene pipes vary widely. The values ​​for outer and inner diameters and wall thickness can be found in the following table.

Polypropylene (PP - according to Russian, RR - according to international classification) pipes are stiffer than metal-plastic pipes, they are assembled using diffusion welding using fittings: angles, tees, etc. Polypropylene pipelines use permanent connections, the pipeline is assembled using welded fittings once and for all. Unlike a metal-plastic pipe, which is essentially a thin aluminum pipe coated inside and outside with a protective layer of plastic, a polypropylene pipe is completely plastic. The plastic used to make pipes also varies. Unlike polypropylene pipes, most metal-plastic pipes use polyethylene.

Due to the special properties of materials piping system made of polypropylene can be used in: water supply to houses; connecting boilers; water distribution; water risers; distribution across floors (regular or at each sampling point with individual connection); connecting the pipeline to existing water supply networks mounted from metal pipes; heating networks; connection to the boiler installation; distribution devices; heating risers; connecting metal radiators.

The long service life of the standard polypropylene pipe allows it to be used for all known species laying of pipelines: open laying, laying on the wall, hidden laying. For internal systems For hot water supply and heating, the most heat-resistant type of polypropylene is used - random copolymer (labeled as PP type 3 or PP Typ 3). Pipelines made of this material, depending on the operating pressure, can serve for a long time with liquid temperatures up to 95°C. The estimated duration of use of the pipeline is more than 50 years, and in cold water supply pipelines it is even longer - from 50 to 100 years. Temperatures of the order of 100°C, resulting from short-term faults, do not have a negative impact on the service life of the pipeline.

All parts of the pipeline that are in contact with drinking water, comply with current Russian standards. The suitability of polypropylene for work in contact with liquid food products is confirmed by national certificates of Belgium, Germany, Great Britain, Italy, Spain, and the USA.

Pipes (Fig. 20) are divided into three categories:

• PN 10 - thin-walled version, for cold water supply (up to +20°C) and heated floors (up to +45°C), nominal operating pressure 1 MPa (10.2 kg/cm²);
• PN 20 - universal pipe, used for hot water supply (temperature up to +80°C), nominal pressure 2 MPa (20.4 kg/cm²);
• PN 25 - reinforced aluminum foil, for hot water supply and central heating (up to +95°C), nominal pressure 2.5 MPa (25.49 kg/cm²).

Polypropylene pipe PN 16 - for cold and hot water supply (up to +60°C), nominal operating pressure 1.6 MPa (16.32 kg/cm²), could be fourth on the list of categories of these pipes, but it is rare.

Rice. 20. Polypropylene pipes

	PN 10 Size, mm	D, mm	S, mm	d, mm
	20×1.9	20	1,9	16,2
	25×2.3	25	2,3	20,4
	32×3.0	32	3	26,0
	40×3.7	40	3,7	32,6
	50×4.6	50	4,6	40,8
	63×5.8	63	5,8	51,4
	75×6.9	75	6,9	61,2
	90×8.2	90	8,2	73,6
	110×10	110	10	90,0
	PN 20 Size, mm	D, mm	S, mm	d, mm
	16×2.7	16	16	10,6
	20×3.4	20	3,4	13,2
	25×4.2	25	4,2	16,6
	32×5.4	32	5,4	21,2
	40×6.7	40	6,7	26,6
	50×8.4	50	8,4	33,2
	63×10.5	63	10,5	42,0
	75×12.5	75	12,5	50,0
	90×15.0	90	15	60,0
	110×18.4	110	18,4	73,2

Unlike metal-plastic pipes, the aluminum layer in PN 25 pipes is closer to outside and, most often, there is perforation on it, which makes it possible not to use glue to fasten the layers of the pipe. The connection of the outer and inner layers of polypropylene to each other or to the aluminum layer occurs through perforated holes, which, in turn, can be through or surface from different manufacturers. The direct connection of polypropylene with aluminum significantly increases the stability and strength of the pipes. PN 25 pipes are intended for special use - mainly in heating pipelines, as well as in hot water supply pipelines, but can also be used for cold water supply systems. For example, this is one of the most “favorite” pipes among domestic plumbers; it is installed on all types of wiring.

Polypropylene pipes come in gray, white, black and green. Color other than black does not mean any restrictions on the use of pipes. The black color of the pipe indicates that it is most protected from ultraviolet radiation.

It should also be noted that the service life of polypropylene pipes declared by the manufacturer is 50 years, which implies that the pipeline will be operated at normal pressure and normal temperature. That is, pipes can withstand long-term significant pressures, but the temperature of the transported liquid must be low, or, conversely, the temperature of the liquid can be very high, but the pressure must be low. At high pressure and high temperature, the service life of the pipe is sharply reduced and can reach 1–5 years. To determine the service life of pipes operating in extreme conditions, there is a special table. We will not present it, since at the household level such long-term loads do not occur in household pipelines, but short-term ones emergency situations associated with a sharp rise in pressure or a sharp jump in the temperature of the transported liquid, the pipe will withstand.

For polypropylene pipelines, we produce all types of fittings necessary for the device engineering communications, which makes it possible to avoid including metal parts in the pipe system and to perform optimal installation of the pipeline. They also allow you to connect a polypropylene pipeline to a metal one. The pipes are environmentally friendly and are successfully used in cold and hot water supply and heating pipelines. Thanks to fittings with chrome and brass inserts, pipes can be easily combined with existing steel fittings and plumbing fixtures.

Coupling with internal