Plastic pipes for heating

The organization of the heating system that in a private house, that in a city apartment is always among the most complex and ambitious.It is important to just about anything, and any seemingly small thing can play its value.And one of the basic requirements, if not to take into account installations generating heat - a high-quality materials and components for the installation of the entire system.

More 20 ÷ 25 years ago hosts special housing options and was not - had to water circuits use only metal pipes of different diameters.This laid a lot of inconvenience and technological difficulties - from the great weight of pipes and problems with the organization of their transportation to the need for special equipment for their installation and, consequently, to use the right skills, skills of work with metal.The situation is different now - to replace metal products came plastic pipes for heating.

This opened very wide horizons for independent work of domestic craftsmen.No, of course, to the heating system turned out high-quality, sustainable skills necessarily needed, but to learn to mount any plastic pipe is much easier than to perform, for example, arc welding.Even tapping on the steel pipe and

reliable «wrapping» its - much more laborious process than, for example, the installation of the compression fittings or soldering polypropylene.The equipment is not that expensive, it is easy for the "funny money" to rent, while many species of pipes - general enough set of wrenches.

The article will be considered by several varieties of plastic pipes - on their technical characteristics, advantages and disadvantages, to major technological installation methods in the heating system.

what requirements must be met when selecting pipes for heating

Sortamen reflux rubnyh products- is extremely great.They differ in the basic manufacturing material, diameter and wall thickness, the absence or presence of any reinforcement, physical characteristics - flexibility, the degree of linear expansion, the ability to attach and save desired shape, resistance and temperature, and pressure loads, ultraviolet radiation and otheroptions - up to color choices.

However, we must understand that heating - a system of very specific, in which all elements are experiencing extreme or close to them load.And any pipe, just reasons of efficiency or ease of installation, will not work here.

• Plastic pipes for heating should be free to withstand the high temperature of the circulating coolant thereon.Although in modern systems the upper limit of heating is typically less than 70 - 80 degrees, yet laid technologists "reserve" should be not less than 95 ° C .With such a heated labor must not be deformed and lose its strength properties (plastic does not have to "go" from an elevated temperature).
• Where high temperatures - there is always an increased pressure.Hence, plastic pipes for heating should guaranteed possible baric system load, including surges, water hammer.This is especially important for home wiring of central heating systems, where owners simply can not control the level of the desired flow pressure.
• pipes must have a smooth inner surface on which will accumulate layers of salts or scale, and which will not cause an increased flow resistance for the coolant circulation.
• Plastic pipes for heating should have the lowest possible coefficient of linear thermal expansion.Otherwise, they will just sag or under heating, or vice versa , they may experience unwanted internal stress when the temperature is lowered.

• One of the main advantages of high-quality polymers - inertia, no susceptibility to corrosion or chemical degradation.This is particularly important when used as a coolant no ordinary water and certain chemical compounds.
• polymer itself is not oxidized, but can pass oxygen from the air to the coolant.And it is likely to eventually lead to corrosive processes on the metal surfaces of boilers, regulating, stop, mounting hardware.Modern technologies allow to successfully combat this phenomenon - pipes for heating can be equipped with special "oxygen barriers".
• pipes must be durable - heating is always installed on the very long term, and operational resources of the pipe does not have to be lower than that of the other elements of the system.
• Not all tenants will be pleasing to the constant sound of running water pressure.So, still one requirement to the heating pipes - their « maloshumnost ».The smooth inner surface of the channel is to provide smooth, without turbulence, fluid motion, and the walls of the material - is not resonating effectively suppress the possible sounds.

• And, of course, since a significant part of the heating system is usually on the mind of the pipe to its appearance should not make "a destructive influence" in the interior.In other words, they need to be if not beautiful , at any rate - very careful.

Modern manufacture of plastics and composite materials technologies allow to create products, almost entirely responsible all specified requirements, to a greater or lesser extent.To date, the regeneration heating systems are widely used various plastic pipes, but the greatest distribution was received by polypropylene and polyethylene, in various combinations and designs.

Polypropylene pipes

General concepts about as a raw material for the production of pipe material

Polypropylene (PP) has been used for a long time.But to apply it in the conditions of high temperature and high pressure has allowed the creation of a modern modifications this material.

huge variety Thus, all polypropylene products are distinguished pronounced chemical inertness - can be used to pump even highly corrosive compounds.But the criteria for strength and heat resistance may be quite large "spreads»:

• The original wide popularity this material brought homopolypropylene (there are different designations - such as "Type 1" or PP-H ).Pipes from PP-H - High-strength, chemically inert, but high temperatures they can not stand.Their typical use - cold water supply, drainage, ventilation ducts, technological production facilities not related to the heating of liquids.
• Polypropylene "Type 2", or a block copolymer polypropylene (PP-2 and PP-B ) - while retaining all the advantages of its predecessor, is more than significant opportunities for keeping performance thermal load. Nevertheless , extreme temperatures, around 80 - 90 ° With he not will take even a short time.Scope The PP pipes, in principle, the same as that of the PP-H.Perhaps its application in hot water systems with limited heating threshold, in « warm floor" systems, where the temperature should not be rolled over for 45 - 50 ° C .
• significantly expanded the scope of polypropylene development technology of the so-called « random copolymer » .During synthesis of the material into the molecular chain of the propylene molecule fragments are introduced ethylene, dramatically changes the performance of the better products.

Static PP "third type", PP-3, PP Rili RRRS - this is the material that is perfect for pipes exposed and compression, and thermal stress.Not at all without compromising chemical inertness and environmental material such upgrade dramatically improves elasticity, viscosity, resistance to elevated temperatures .

Polypropylene PP-R it became one of the basic materials for the production of pipes for various purposes.It is used both in pure form and still create multilayer structures.

pipes can vary in color - available in white, grayish, with varying degrees of saturation, green or shades of blue and etc .By the way, this does not say anything about their some features, rather, here it plays the role of the desire of some of the leading manufacturers in some way to differentiate their products.

exception may be a pipe black color - a coloring usually give products which are characterized by high resistance to ultraviolet rays.And yet - pipes for sewerage or drainage systems made to give an orange color.One the installation of heating or black, orange or pipes are not meet, so consider them no there is no need.More

tell longitudinal colored stripe on the tube.Here everything is simple and clear - blue bar indicates the possibility of using only cold water in the system, and red - on-RT pipes.By the way, the band is not applied to all products - it is better to pay attention to the marking.

fact that PP-R pipes differ in several respects.The first, of course, what to look for - is the outer diameter and wall thickness.Standard values ​​of diameters which are used for creating a home heating - 16, 20, 25, 32, 40, the maximum - 50 mm.As a rule, the larger the pipe used in the heating system of a private house just do not want - there is no such significant amounts of coolant pump.However, on its own diameter - the option is not saying a lot, and it can not be seen in isolation from the pipe-type figure, in the name of which is indicated by the rated working pressure of the hydraulic system.Total of four types of defined - from PN -10 to PN -25.Features and scope of application - in the attached table:

type polypropylene pipes	Nominal working pressure	Scope of use pipes
	MPa	technical atmospheres (kgf / cm ²)
PN 10	1.0	10.197	Cold water supply, as an exception - underfloor heating to the level of heating to 45 ° C
PN 16	1.6	16.32	hot and cold water with a water temperatureup to 60 ° C
PN 20	2.0	20.394	hot and cold water, heating system with a low level of coolant pressure (autonomous systems)
PN 25	2.5	25.49	hot water supplyand all kinds of heating systems, including - central (with water temperature to 95 ° C)

Scope is indicated for good reason - it is the result of research, during which studied not only limit the possibility of pipe, but also the durationtheir safe operation in such extreme conditions.

temperature (° C)	Life (years)	tube type
		PN 10	PN 16	PN 20	PN 25
		Permissible excess pressure kgf / cm2
20	10	13.5	21.7	21.7	33.9
25	13.2	21.1	26.4	33
50	12.9	20.7	25.9	32.3
30	10	11.7	18.8	23.5	9.3
25	11.3	18.1	22.7	28.3
50	11.1	17.7	22.1	27.7
40	10	10.1	16.2	20.3	25.3
25	9.7	15.6	19.5	24.3
50	9.2	14.7	18.4	23
50	8.67	13.9	17.3	23.5	21.7
25	8	12.8	16	20
50	7.3	11.7	14.7	18.3
60	10	7.2	11.5	14.4	18
25	6.1	9.8	12.3	15.3
50	5.5	8.7	10.9	13.7
70	10	5.3	8.5	10.7	13.3
25	4.5	7.3	9.1	11.9
30	4.4	7	8.8	11
50	4.3	6.8	8.5	10.7
80	5	4.3	6.9	8.7	10.8
10	3.9	6.3	7.9	9.8
25	3.7	5.9	7.5	9.2
95	1	3.9	6.7	7.6	8.5
5	2.8	4.4	5.4	6.1

Asit is clear from the above data for use in heating systems are only suitable pipe type PN -20 (with reservations), but still the best solution - PN -25.

Advantages and disadvantages of polypropylene pipes

use of polypropylene pipes is a number advantages:

• Easy material itself determines the absence of major difficulties in transportation, delivery pipes to the place of work - not tedious nospecialized equipment or lifting devices.