Do-it-yourself polypropylene plumbing: everything about installing a system of plastic pipes

Nikolay Fedorenko
Checked by a specialist: Nikolay Fedorenko
Author: Inna Alekseeva
Last update: March 2019

Comfortable housing, whether it is an apartment, your own cottage or a small country house, is inconceivable to imagine without running water. The supply of cold and heated water has long been a prerequisite for a comfortable stay. Homeowners are trying to choose the most practical option for water supply.

Statistics show that most people prefer polypropylene plumbing: even an inexperienced plumber can equip such a system with their own hands. To ensure that the result of your efforts is impeccable, we suggest that you familiarize yourself with the detailed polymer system assembly technology.

We presented all the methods for joining polypropylene pipes, and presented the types of fittings used in the construction of circuits. Indicated typical errors. The information we have proposed is supplemented by diagrams, photo collections and videos.

Why choose polypropylene?

Steel has long been considered a traditional material for water pipes.

However, today this option is rarely used. He was replaced by various plastics, among them - polypropylene.

The popularity of PP pipes is not accidental, because the material has many advantages:

  • High stability to aggressive environments During a long time. In addition, polypropylene is not subject to corrosion.
  • Durability. The manufacturer guarantees trouble-free operation of its products for at least 50 years, which is three times more than that of analogues.
  • Good tightness of joints. Compared to other types of plastics, it is considered the best.
  • High sound absorption. The noise of water passing through the pipeline is completely absorbed by the material.
  • Total environmental safety polypropylene, it is allowed to use for the arrangement of drinking water supply.
  • Low hydraulic resistancetherefore there are no pressure losses.
  • Light weight, which greatly facilitates the installation, repair and transportation of parts.
  • Easy installation. This is due to a wide range of components, the convenience of cutting and fitting parts.
  • Possibility of concealed styling the pipeline.

The most significant disadvantage of polypropylene pipes can be attributed to a high value of thermal expansion and low heat resistance, which requires special attention when choosing a material for arranging hot water supply.

In addition, polypropylene is non-plastic, so the use of connecting fittings is required to change the direction of the trunk branch.

The use of polypropylene in the construction of a water pipe do-it-yourself
Due to the technical qualities of PP pipes can be used both in the construction of new water supply networks and in the connection of new branches to existing metal circuits

Another disadvantage of such pipes is the need to use special equipment. To connect parts, soldering is used, which is performed using a special soldering iron.

For cutting elements, it is advisable to use special scissors. True, this flaw is easily corrected. Most shops selling polypropylene pipes provide soldering equipment for rent.

DIY polypropylene plumbing
Polypropylene pipes are a great alternative to traditional steel parts. They are not subject to corrosion, resistant to aggressive environments, environmentally friendly, reliable and durable.

Features of the assortment of polypropylene pipes

Polypropylene is a type of plastic obtained by cracking petroleum products and petroleum gases. Its base is propylene gas. Under high pressure with the presence of a catalyst, the polymerization reaction is carried out, as a result of which polypropylene is obtained. Pipes are subsequently produced from it. For water supply, two varieties of such products are produced: one and multi-layer.

The first option is intended mainly for various types of pipelines through which cold water is transported. Multilayer or reinforced parts are used to equip hot water mains, they are also used for installation of heating systems. Their main difference is the presence of several layers of polypropylene, between which a reinforcing material is laid.

It can be aluminum foil, polyethylene or fiberglass. Details differ in the thickness of the reinforcing layer and base.

In the manufacture of polypropylene pipes, such marking of the material used in the manufacture is used:

  • PP-N. Products for cold water, can be used for ventilation systems.
  • PP-B. Material for products with high impact resistance. Designed for arranging cold water supply and floor heating.
  • PP-R. Pipes made from it can be used to equip any type of water supply.
  • PPs. It is used in the production of flame-resistant products intended for pipelines through which dangerous substances are transported.

The classification of materials used in the manufacture of pipeline products from thermoplastics for the construction of communications is given in GOST No. 52134-2003.

DIY polypropylene plumbing
Single-layer polypropylene pipes are mainly used for transporting cold water

Marking of finished products is different. For polypropylene pipes, the following nomenclature is used:

  • PN10. Products manufactured for transporting cold water with a working tº of not more than + 20º C.
  • PN16. Universal products that can be used for the construction of water pipelines with cold and hot water. However, the temperature of the liquid should not exceed + 60º C. It is rarely produced, moreover, in limited quantities.
  • PN20. Pipes providing normal fluid transportation tº + 80ºС. By analogy with the previous view, it is among the universal ones.
  • PN25. High pressure resistant parts can be used for both water supply and heating. The pipes are reinforced with aluminum foil; they can be used in transporting water with temperatures up to + 95ºС.

According to the marking of the pipes, the pressure that the PP pipes can resist when moving water through them is determined. For example, pipes PN 10 operate normally at 1 MPa, PN 20 at 2 MPa, PN 25 at 2.5 MPa.

Polypropylene is sensitive to ultraviolet, so pipes of different colors are produced. The greatest resistance to UV radiation are black parts. The production of polypropylene pipes is standardized, so they are available in certain sizes.

Reinforced pipe
Reinforced multilayer pipes can withstand higher temperatures and pressures. The reinforcing layer may be aluminum, as shown, or fiberglass

The first thing you need to pay attention to is the inner and outer diameters. They can be marked in inches or in familiar millimeters. The diameters determine the selection of the dimensions of the reinforcement that will be used for joining the pipeline parts.

The outer diameter of the product varies from 16 to 500 mm. The length of the pipes can be from 2 to 5 m, which is quite enough for the arrangement of an intra-house water supply. Moreover, the products are easy to process.

Parameters of polypropylene pipes PN 10 and PN 20
Diameters of PP pipes must be taken into account when selecting fittings for pipeline assembly. It is assembled through tear-off connections using fittings and tees (+)

Accessories for pipes made of polypropylene

For mounting water pipes from plastic pipes various components are used. Their assortment is very extensive and counts in dozens of positions in the price lists of manufacturers. Details vary in shape, size and purpose. Consider the most common types of such elements.

DIY polypropylene plumbing
For pipes made of polypropylene, a large number of components are produced. When buying them, it is important to choose parts from the same manufacturer as the pipes

Couplings. The simplest connecting piece. The shape resembles a small barrel, the inner diameter of the hole of which exactly corresponds to the cross section of the connected pipes. The element is designed to connect two pieces of pipe.

Adapters These parts are designed to connect pipes of different diameters. Outwardly, they are very similar to couplings, but their main difference is that the inner diameter of the two opposite ends of the element is different.

Adapters are selected according to the diameter of the connected pipes and come in various sizes. Parts with internal or external threads are available for transition to threaded connections.

Corners. As known, polypropylene pipes You can not bend. Therefore, to complete the necessary turns during installation, the manufacturer produces special fittings, bent at an angle of 90 ° and 45 °.

Corners can end with holes for pipes or have threads, both internal and external. For example, such parts are used for mounting the mixer. Moreover, they can be either double or single.

Some home craftsmen argue that you do not need to complicate and use the corners. After all, polypropylene is plastic and can be bent. They heat the pipe to a softening temperature and bend it as they need.

Indeed, it is very easy to bend a part, but you need to understand that at the same time unpleasant changes occur in it: the wall on the outside of the bend becomes thinner. This will significantly reduce the service life of the pipe and lead to its breakthrough.

DIY polypropylene plumbing
The polypropylene shut-off ball valve is installed in the water supply system by soldering

Crosses and tees. This is the name of the elements designed to connect three or four pipes simultaneously, which is often required for the installation of a water supply system. Available in a wide variety of variations: with different hole diameters, with fittings for pipes of other types, for example, for metal-plastic or copper, with internal and external threads of various sizes.

Contours. These are called specially formed bends, which are used to circle the pipe around a small obstacle. It is desirable that the distance from the pipeline to the wall is minimal. The contour is welded into the gap in the water supply section so that the pipe sections lying before and after it are straight.

In addition to these components, other elements are also available. Among them are plugs used to block unnecessary water supply branches, special ball valves for polypropylene pipelines.

To fix the pipes to the wall, special clips are used that are selected according to the diameter of the part. They can be single or double.Experts advise choosing pipes and accessories from the same manufacturer. So there will be less problems during installation, and the system will turn out to be better.

Connecting parts for installation of a water supply system from PP pipes
For PP pipes of all sizes, a wide assortment of fittings is produced, which allow the installation of a plastic circuit at a fast pace and, if necessary, connect it to metal branches

Starting phase: where to start?

First of all, you need to draw up a competent project of the future system. By this is meant a scaled-out schematic plan of a pipeline on which all design features are applied and consumers are indicated.

For this, it is necessary to carry out accurate measurements, according to which a building drawing is subsequently built. After it is completed, a pipeline scheme is built.

DIY polypropylene plumbing
For the distribution of water pipes, you can choose one of two options: tee or collector

At project creation different options for the placement of plumbing are considered, and the optimal one is selected. In addition, several factors must be considered in the design process. The first is the type of wiring.

It can be tee or collector. In the first case, the water points are connected in series, one after the other. On the one hand, this is good because it requires a minimum number of pipes and, therefore, low costs.

However, the pressure in water-consuming devices will be different. The farther from the beginning of the pipeline, the lower the pressure. This is extremely inconvenient, and in the case of a large number of draw points, it is unacceptable.

Collector wiring assumes the presence of a special distribution unit that separates the flows of water and directs an individual branch to each consumer.

Polypropylene sewer assembly
For the collector assembly of the pipeline from PP products, you can use a ready-made distribution unit or assemble the collector yourself using connecting parts

In this case, there is practically no pressure loss in the system, all devices work with the same water pressure. The main drawback of the collector wiring is the high consumption of pipes and, consequently, the higher cost of the entire structure.

The second important point is the installation of the pipeline. You can do this with an open or hidden method. The second is more aesthetic and involves laying pipes inside walls or partitions.

DIY polypropylene plumbing
The open laying method assumes that the pipes are fixed over the wall. Closed - fit into the strobes made in the base

In addition, experts recommend that when designing a pipeline, reduce its length as much as possible. The number of bends and joints should be minimal. This is because it is in these areas that the risk of leakage is most likely.

Turning the pipe at right angles reduces the pressure in the line, this also needs to be taken into account. According to the finished scheme, the required amount of materials for laying the water supply is calculated.

Concealed installation of water pipes from plastic pipes
Technical characteristics and 50 years promised by the manufacturers of excellent service of PP pipes allow manufacturers to lay water pipe branches in a hidden way

How to connect polypropylene pipes?

Soldering is used to connect pipe segments made of polypropylene. It is carried out using a special soldering iron. Using such a device is not difficult. Anyone, even the most inexperienced plumber, can learn this very quickly.

Process soldering polypropylene pipes as follows. First you need to prepare the parts to be soldered. To do this, sections of pipe fastening are outlined on the wall.

After that, using the level, the correct marking is checked, then the so-called clips or mounting supports are installed on the wall. Then you need to measure the pieces of pipe that need to be connected, and then cut them with a cutter or special scissors.

Now you can start soldering. First you need to choose a nozzle for a soldering iron. Included with the device are several of these elements.

DIY polypropylene plumbing
A soldering iron for mounting polypropylene pipes can be rented. Included with it are nozzles for different diameters of pipes and fittings

They differ in the diameter of the working surface. The nozzle is selected in accordance with the cross section of the pipe and fitting. The part is put in place and the soldering iron is turned on. There is always a temperature controller on the device’s case, with which you can control the heating of the nozzles.

For work with polypropylene it is recommended to choose a range of 250-270ºС.

The fitting and pipe are put on the corresponding heated tips of the soldering iron and heated for about 5-10 seconds. It depends on the diameter of the elements. The larger it is, the longer the warm-up time, respectively.

After the details will warm up, they are removed from the nozzles and immediately pressed against each other. In this case, it is impossible to make a twisting motion. Elements do not rotate, but press one against the other.

In this position, they are held for about half a minute. During this time, the plastic will have time to harden and you can remove your hands. After the polypropylene is completely cooled, a strong monolithic connection of two nodes is formed.

A sign of quality work is a uniform bead that is visible around the entire circumference of the pipe. It is also inside the fitting, it just cannot be seen there.

DIY polypropylene plumbing
The parts are heated to the desired temperature on the tips of the soldering iron, after which they are firmly pressed against one another

A collar is formed when a part is heated. If it is uniform, then warming up was normal. With uneven heating of the parts, the height of the flange will be different. Where it is least, a leak is subsequently likely.

An important point is the quality of the tips for the soldering iron. They are coated with Teflon so that plastic does not stick to them. In the process, the Teflon layer becomes thinner and even disappears.

Specialists strongly discourage the use of nozzles partially coated with a non-stick coating. This is due to the fact that when heated, the plastic will necessarily stick to those parts of the nozzles that are not covered with Teflon.

This does not mean that the part cannot be removed from the nozzle. It will be perfectly removed, but the connection will be of poor quality. It is very likely that where the element adhered to the nozzle, a leak will subsequently appear.

General mounting features

For a novice plumber it may seem that the process of installing a polypropylene pipeline is complicated, but it is not. Before work, it will be necessary to prepare all the necessary materials. Their type and quantity is easily determined by a pre-compiled design of the structure.

If such work is performed for the first time and the welding experience is still very small, you should buy everything “with a margin” in case of possible damage.

DIY polypropylene plumbing
Components and pipes must be purchased with a small margin, since during the soldering process it is easy to spoil the material

The installation of the water supply should begin not from its beginning, as it may seem, but from the points of drawdown. Fastening to water-consuming devices is carried out using suitable sized adapters with a threaded connection.

Before each plumbing fixture, it is strongly recommended to install ball valve, which will allow you to quickly turn off the water supply if necessary.

From the consumer, the branch goes to the collector or to the next pickup point. It depends on the type of wiring. In any case, the pipe is laid so that it can be repaired without any problems. To do this, it is fixed so that the distance between the wall and the part is at least 20 mm.

Fixing clips are placed at a distance of not more than 1.5 m from one another, as well as at each corner junction and cornering.

It is important to try to minimize the number of pipes passing through partitions or walls. Each of these passages should be equipped with a sleeve or a glass, into which pipes are laid.

If there are drain taps in the system, the pipes should be laid with a slight slope in their direction. All walks and corners are carried out only with the help of special fittings.

DIY polypropylene plumbing
Connection to the collector is carried out only through shutoff valves, so that, if necessary, it is possible to easily disconnect the branch

When the branch is pulled up to the collector, it is connected. It should be remembered that before connecting to the outlet of the collector, it is necessary to put shutoff valves as close as possible to it.

Each branch of the water supply is connected to "its" outlet of the collector. This is true for both cold pipelines and hot water pipelines.

If the number of exits on the collector comb is more than necessary, the excess can be cut off. After that, a plug is welded to the open part. In the case when there are not enough outputs, you can additionally weld a square-coupling.

It is best that it is already with the transition to the desired diameter in the work. If you wish, you can make a homemade collector with the desired number of outputs by welding it from several fittings.

At the last stage of the installation of plastic water pipes, the branches prepared and connected to the collectors are assembled into a single system. Consider a typical version of this design. Its beginning falls on the section of the tie-in to the centralized highway.

If it is about autonomous system, then its beginning will be considered the place of connection to the well, well or other water source. In the first case, water meters are installed immediately after the insertion section.

If the water supply is connected to a private house, then some part of it will be laid along the street. This is the so-called external section of the highway.

In areas with a cold climate, the external water supply is laid in a trench, the depth of which exceeds the level of freezing of the soil. At the same time, it is still desirable to insulate the trunk so that the water in it does not freeze in the most severe colds.

DIY polypropylene plumbing
Water meters must be installed on a water supply connected to a centralized highway. With their help, water consumption is recorded

The system is brought to the house, it is put into the building, and then the installation of the internal plastic water supply is carried out. A coarse filter must be installed at the pipe inlet into the house or apartment.

It will be quite enough to get rid of the largest particles of pollution present in the water. Further, before each household and plumbing fixture, it is desirable to install more filters.

In the kitchen, cleaning equipment is usually installed suitable for specific conditions, such as to obtain drinking water. If it is planned to organize water heating, then a tee should be installed after the coarse filter. It will divide the incoming water flow into two branches. The first will be cold, the second will be hot.

The pipe with cold water immediately after the tee must be connected to the appropriate collector. He, in turn, is connected to the wiring going through the building. The branch along which the hot water will move is first connected to the heating device. This must be done exactly according to the instructions.

Next, a collector for hot water is mounted. Everything else is similar to a “cold” pipeline.

Common mistakes and how to avoid them

Errors in the work are quite possible. To prevent an unpleasant situation, you should find out what are the most common mistakes to try to prevent them. All branches of pipelines near the points of water intake must end with couplings with an external thread, which is used to connect plumbing. This is true for all devices except the bathroom faucet.

This will require fittings with internal thread. This is often forgotten, and you have to either buy new couplings or put on the legs. Many errors are associated with soldering pipes.

If during the alignment process the pipe is not fully inserted into the fitting, a small gap will remain between its inner part and the end of the part. It is a section with a smaller wall thickness and a larger inner diameter than the pipe itself.

For this reason, the operating pressure in this section will be lower than in the rest of the system. Another problem may arise with excessive force, which is applied when connecting two parts.

In this case, the shoulder formed during the compression process will be too high. It will become an obstacle to the movement of water through the pipeline. Overheating of elements gives a similar effect.

DIY polypropylene plumbing
The performance characteristics of the new water supply depend on the quality of the soldering of polypropylene pipes. There should not be underheating or overheating of parts

The internal section of the parts is reduced, and outwardly it is completely invisible. Dangerous and insufficient heating of the elements.

The connection will look absolutely normal, but it will be extremely unreliable and will leak quickly enough. To prevent this, it is important to always pay attention to the temperature of the soldering iron and remove the heated parts only when the control lamp goes out.

Conclusions and useful video on the topic

Clip # 1. All about the types of polypropylene pipes:

Clip # 2. Professional plumbers reveal the secrets of working with polypropylene pipes:

Clip # 3. Example of incorrect pipe soldering:

Plumbing from polypropylene pipes is an excellent alternative to the traditional metal system. Many advantages make its use very attractive for homeowners, and the relative ease of installation allows you to cope with the installation of such a system, not even the most experienced home master.

However, the advice of professionals should not be neglected. Then the new water supply will please you with a long and uninterrupted operation.

Would you like to tell how you independently assembled a polypropylene pipeline? Do you know the nuances that will be interesting and useful to site visitors? Please write comments in the block located under the text of the article.

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Visitors Comments
  1. On the one hand, such pipes are a real salvation from corrosion and the need to constantly paint the pipeline. But on the other - they are more difficult to repair if a similar need arises. Naturally, more often a leak can form at the junction, and here it’s not enough just to wind up the tow, tighten or install a clamp - you need to redo the entire assembly. One advice - to buy high-quality materials and not skimp on the call of a good master.

    • Expert
      Nikolay Fedorenko

      Igor, everything is perfectly repaired, much easier than on steel pipes. In extreme cases, just cut out a piece, and solder a new one in 10-15 minutes.

  2. I fully agree that polypropylene pipes are much more practical than steel pipes and have a lot of advantages compared to them. But about the ease of installation, I would argue. To sit down to solder PP pipes is not skillful - not the best idea. In addition, the service life of such pipes is long, so once in a lifetime you can, as they say, go broke and hire a normal craftsman. Moreover, installation will still require special equipment, which you buy only to make yourself a water pipe is stupid.

    • Victor

      In fact, you can buy a soldering iron for thousands and a half and it will be quite suitable for use (for sure). I believe that in the arsenal of any man should have a set of necessary tools, ranging from a screwdriver to just a simple soldering iron.

      Slightly distorted when I read about the fact that plastic has some significant drawbacks, while polypropylene pipes are the most ingenious invention in plumbing for the entire existence of this area of ​​activity. Plastic completely changed the idea of ​​plumbing in terms of reliability and durability. As I recall this fuss with metal, it thrills.

      • For polypropylene pipes, special soldering irons are used. How often do you solder PP pipes to spend money on it? Yes, a man should have a set of tools, but if you buy every highly specialized tool, then there will not be enough money.

        • If there is no 2000-2500 r for the purchase of a soldering iron, then you can catch it in some sale, which is always full. I believe that a 2000 watt soldering iron should be in any family household. Relatives can be given for use, if that. And soldering can impatient at any time. From the installation of a summer shower to a full replacement of plumbing in the house. A man should have as many tools as needed.
          A grinder, a puncher, a drill for metal, a screwdriver, an electric jigsaw, an end saw, a chain saw, a plane, a welding machine, a grinder, a concrete mixer - this is a very important list, against which buying welding for pipes is a drop in the bucket.

        • Expert
          Nikolay Fedorenko

          Hello. The acquisition of such a soldering iron is beneficial in self-assembly of an autonomous water supply system. The cost of budget models is quite low, as the commentator answered below - from 2500 thousand. It depends on the region, but in our city, for example, 1 soldering point costs about 180-300 rubles by specialists, renting a tool costs 1000 rubles in 24 hours.

          And if you need to repair the pipes, replace their individual parts or modernize the water supply, take water out to the street for irrigation or an outdoor shower, the benefit in buying becomes even more obvious.

  3. Volodya

    Please help me choose which material should be a pipe for hot water heating diameter 16. We live on the last floor and there is a common pipe. The last 50 years steel, but whole, hot. Neighbors want to change at home, is there a need for me to do this? I know that the heat transfer of plastic pipes is low - is it worth it to deprive yourself of heat? And if you have to do this, then what material should it be from? Thank.

    • Expert
      Nikolay Fedorenko

      Hello. I don’t understand if the pipe is whole, what is the point of changing it. Moreover, you live in an apartment where an independent replacement involves repair, responsibility and maintenance by you personally in case of problems, and not the Criminal Code. That is, if you really want out of aesthetic reasons - change, and if you are in thought - the neighbors change, maybe for me, then it’s not worth it.