Which pipe to choose for water supply: we figure out which pipes are better and why

Nikolay Fedorenko
Checked by a specialist: Nikolay Fedorenko
Author: Marina Sturova
Last update: June 2019

The range of pipes for the communications device is extensive. Products are significantly different in their characteristics: material, flexibility, strength, durability. It is often difficult for the user to determine which pipe to choose for the water supply of a house or apartment.

The type of pipeline and transported medium, the number of plumbing points in the network - all these factors that drag the scales favor the choice of one or another type.

In our material, we will try to deal with the intricacies of choice, and also talk about how to determine the optimal diameter of the pipeline.

Pipe selection for operating conditions

TO domestic water supply the piping system (wiring) refers, which transports water to plumbing, equipment. Pipes and fittings made of polyethylene, polyvinyl chloride, polypropylene, polybutylene, metal polymers may not be used for all networks. Each of them has its own operating conditions and they can vary greatly.

Without restrictions can be used copper pipes, brass, bronze - for high-pressure systems, for the transportation of drinking and industrial, cold and hot water. Steel products with external and internal anti-corrosion coating can also be used for any purpose.

Pipe laying in stubs
To avoid possible damage, plastic pipes are hidden in plinths, channels built from GVL boxes. They must not be placed near open flames or in places subject to direct sunlight.

For each type of pipe and their size, the maximum pressure in the network that they can withstand is determined. It is better that it is higher than the maximum possible pressure in the water supply network.

For example, in a house with centralized water supply water pressure can fluctuate between 2.5-7.5 bar with a norm of 4 bar.In this case, peak values ​​can sometimes reach 10 bar, and system testing is carried out at values ​​of 12 bar. So that the pipeline does not break, when choosing pipes, a "safety margin" is provided with a reference to maximum performance.

Choosing pipes for the construction of external underground systems, pay attention to the indicator of ring stiffness. When channeling a polymer pipeline in the ground, in which it may be damaged, products with a protective coating are used.

One of the factors determining the choice is operating conditions:

How to determine the required pipe size?

For convenient determination of the diameter of pipes and fittings, their binding to all elements of the system, use the value of the internal diameter (Dy - conditional passage of pipes). Oriented to typical sizes of steel pipes - they are produced with Dy - 15 mm, 20 mm, 25 mm, 32 mm.

Delivery Length steel pipes It can be different, mainly these are segments from 4 to 12 m long. Plastic pipes can have a diameter (Dy) 16-30 mm and a wall thickness of 2-2.5 mm.

Plastic pipe
Metal-plastic and plastic pipes are delivered to wholesale and retail distribution networks in bays or sections. The total length of the products should be with a margin - 2-5% more than what is provided for in the project (if this stock was not initially included in it)

The choice of the diameter of the future pipeline depends on such factors:

  1. Water pressure in the network. The lower it is, the larger the diameter should be. A thin pipe with insufficient pressure will give only a thin stream of water.
  2. Pipeline lengths. The greater its length, the lower the pressure in the network and, accordingly, it is necessary to use a larger diameter.
  3. The number of turns and joints. Each such element reduces pressure. Choosing pipes with a large diameter, it is possible to increase the flow of water into the house.

These factors are related to the properties of the pipeline itself. In addition to them, water temperature, pumping equipment parameters and much more are taken into account.

There are special formulas for accurate diameter calculation, but the general rule when buying is not to decline your choice in favor of saving by reducing the diameter of the pipe.

In a narrow pipeline, more hydraulic losses occur, which will have to be compensated by a more powerful pump and a large amount of electricity necessary for its operation, and this is an additional cost.

At installation of the pipeline in the apartment most often there is no need for calculations - there is already a wiring at the input. Its dimensions are known, they are designed for the desired flow rate. Usually, before entering the apartment, the common pipeline is mounted from pipes, Dy which is 20–32 mm, for apartment wiring use pipes with Dy 15-20 mm.

Pipe diameters
The diameter of the polymer pipes may be different for different types. But since the input of the pipeline into the apartment, as a rule, is made of steel, in the manufacture of polymer products, manufacturers often focus on the ability to connect them to pipes with standard values

Characterization of pipes from various materials

When choosing pipes for water supply from a certain material, physical and mechanical characteristics are taken into account, as well as operating conditions - maximum temperature, operating pressure, and service life. All parameters are prescribed in normative acts and must meet state standards.

Option # 1 - Steel Pipes

The main thing that a metal pipeline is valued for is strength, resistance to high temperatures, excess pressure in the network and external mechanical damaging influences.

But those few shortcomings that exist in such products, sometimes delete them from the list of products available and convenient for installation.

Metal pipes
The main advantage of metal pipes is their strength, durability and a huge scope

Firstly, it is low corrosion resistance, if it is not copper or brass pipes, it significantly reduces the service life, worsens the quality indicators of the water supply system as a whole.

Secondly, a lot of weight, which creates additional difficulties during installation. And, thirdly, the problems that arise when connecting different parts of the water supply system are the need for threading and the inaccessibility of shaped products from expensive metals.

Products are used for installation of external and internal water supply networks, hot and cold pipelines. They can be galvanized and not galvanized. The first serve a little longer and clog less. But over time, they also lose the protective layer and, like non-galvanized ones, begin to rust. On average, steel pipelines have been around for 40 years.

Steel pipes are produced with different wall thicknesses, according to these parameters they are divided into light, ordinary, reinforced. The thicker the wall, the longer the product lasts and vice versa. Reinforced pipes are harder to cut, they require great effort in bending.

Pipes are easily amenable to gas welding, but, nevertheless, their installation is more difficult to carry out than installing a pipeline of other materials.In addition, welding can be used not always and not in all rooms.

Steel units and parts are ordered in specialized workshops and stores. To connect the pipes, a thread is cut into them:

  • in half an inch, if Dy= 15 mm;
  • three quarters of an inch at Dy= 20 mm;
  • in one inch, if Dy= 25 mm.

They are called, respectively, half-inch, three-quarter inch and inch pipes.

The main disadvantages of the steel pipeline are weak anti-corrosion properties, a high degree of clogging. It must be periodically cleaned of the formed plaque, otherwise it loses its throughput. At the same time, alkaline products that corrode metal cannot be used, and pipes begin to leak over time.

Purified water passing through old water supply networks enters the consumer enriched with harmful chemicals and microorganisms
Purified water passing through old water supply networks gets to the consumer “enriched” with harmful chemicals and microorganisms

Option # 2 - copper pipes

The copper pipeline is least affected by negative factors affecting strength and durability. It does not lend itself to corrosion, does not form plaque, does not deform due to a change in the temperature regime.

When interacting with chlorine compounds that are contained in the water of a centralized water supply system, it does not form harmful compounds.

Copper pipe
Copper pipes are easy to process - they can be easily bent or joined using gas welding or high temperature brazing

If you compare copper pipe with other types of pipes for water supply, it can be noted its extremely high cost. This is perhaps his biggest drawback.

But then he serves more than 70 years. It is often used if it is impossible to conduct a hidden installation of a water supply system, and the aesthetics of the room must be preserved.

Option # 3 - plastic pipes

The choice of pipes made of plastic is made taking into account their purpose, working conditions - the temperature of the water used, the maximum working pressure, etc. For all the similarity of the material for production, the properties of different types of products can vary greatly.

Due to the many positive characteristics, plastic pipes are often used in the design and construction of pipelines. They are characterized primarily by high corrosion resistance.

Unlike metal products, they do not require a special protective coating, have a lower mass, which simplifies and facilitates the installation process, transportation. Their inherent flexibility allows to reduce the number of bent inserts, connecting elements.

Plastic pipes have a smooth smooth surface and, due to this, are distinguished by a small hydraulic resistance, increased throughput (do not clog). They are not subject to corrosion, are characterized by low thermal conductivity, which eliminates the formation of condensate.

Pipe Durability Schedule
The projected life of the plastic pipeline is 50 years. But it must be remembered that the manufacturer indicates the timing for the product to operate at a certain and stable temperature

Of the shortcomings - they are easily damaged, are negatively affected by negative temperatures, becoming fragile. It is strongly recommended that installation at sub-zero temperatures. They can not be used in the construction of wiring sections passing near open sources of fire and in places of direct sunlight.

The temperature of the water transported through the pipeline, which differs from the normative indicators, also has a negative effect on the service life of the products. Besides, plastic pipes during storage, transportation and operation, it is necessary to protect from sunlight and mechanical damage.

The linear expansion problem inherent in plastic pipes is solved with the help of special compensators, which bend when heated and cooled.

Plastic pipe is a general characteristic of products made on the basis of plastic. This includes products made of polyethylene, polypropylene, unplasticized polyvinyl chloride.

The pipeline made of polyethylene (PE) is used to supply cold water for household and drinking purposes with a temperature from 0 ° C to 40 ° C, with a maximum working pressure not exceeding 25 bar (the exact value depends on the pipe size). Installation of elements is carried out by welding.

Polypropylene pipes (PP) include several types of products, which may differ slightly in the composition of the raw materials for production and are designated as PPH, PPR and PPB. Used for transportation of household and drinking water (except for those used for fire safety networks).

They withstand temperatures of 70–80 ° C, and have reduced resistance to bending and shock loads. These properties are especially pronounced at minus temperatures.

Pipes, depending on the class of operating conditions, can withstand pressure of 4, 6, 8 or 10 bar. Their connection is carried out by welding, with a special butt or butt socket, as well as using thermistor welding.

Unplasticized polyvinyl chloride (PVC-U) pipes are suitable for transporting water for any purpose with temperatures from 0 ° C to 45 ° C. It is not permissible to use this type of product for hot water.

It can be used for external above-ground and internal cold water supply networks, provided that it is protected from sunlight and mechanical damage. The connection of parts is carried out with a socket using glue.

Shaped products
For each type of polymer pipe, manufacturers stamp parts with a specific configuration. Therefore, it is necessary to choose only the same type of pipes and assemblies

Units and parts for mounting a plastic pipeline are produced in the factory. A wide selection of their configurations and sizes makes it easy to assemble the most complex plumbing systems.

During the acquisition, unwinding of coils or installation, make sure that there are no flattened sections, fractures, and strong bends on the pipes. If such a site is still found, it must be removed - it is not suitable for installation.

When buying products, they are inspected for cracks, burrs, traces of peeling. Often these defects appear due to improper storage or transportation.

Wall thickness, outer diameter are selectively measured. Check the performance of valves and taps. Shaped elements should be without breaks, sharp edges, burrs. Rubber gaskets and cuffs should not have tears, shells.

Plastic pipe defects
The presence of defects in the form of peeling layers and bubbles on the surface indicates poor product quality, violation of production technology

Each manufacturer of water supply products must provide data on the properties of water that can be transported by this type of pipe, the features of its use, including how to withstand penetration into the air system. The material of the pipe should not affect the composition and quality of water.

Option # 4 - plastic pipes

Pipes made of metal-plastic combine the characteristic properties of metal and plastic - strength, flexibility, corrosion resistance, and no plaque.

They are made of several layers of durable polyethylene, welded together “overlap”, and an interlayer of aluminum, which serves as a frame. The metal layer may be solid, perforated, or spiral.

The basis of the pipe is the inner polyethylene layer. It performs a bearing function, gives strength, thanks to a smooth surface eliminates the formation of scale and layering.

The inner aluminum layer of the foil prevents the penetration of oxygen into the water supply, stabilizes the linear expansion. The outer polyethylene layer serves as protection for the inner layers.

The device of a plastic pipe
The expansion coefficients of metal and plastic are different, and constant temperature jumps over time lead to weakening of joints and leaks. This feature is taken into account when mounting pipes and preventing their tension, and in the places of bends, providing compensation loops

This type of product is designed for the installation of plumbing and heating systems. Withstand pressure up to 16 bar and temperature up to +90 ° C. They can be used for transportation of both hot and cold water, suitable for cooking and household needs. The service life of a metal-plastic water supply system is 20-50 years; the actual life depends on the quality of installation and operating conditions.

Are delivered metal pipes in bays, complete with special fittings designed for their type. Unlike steel pipes, there is no need for threading for metal-plastic pipes; the joints are made using special detachable and one-piece fittings.

Installation of the pipeline can be carried out without the use of welding equipment, which means that it can be installed where welding is prohibited

Pipe bender
The pipe is afraid of repeated bends.To properly bend it, use a special spring - a pipe bender

The connection sections of the segments and reinforcement are a weak link in the system of metal-plastic. Connections must be tightened periodically, at least once every two years. But in general, experts speak well of the properties of metal-plastic pipes and call them one of the most acceptable options in a relatively inexpensive price segment.

Conclusions and useful video on the topic

Differences of pipes made of plastic - polypropylene, polyethylene, metal-plastic:

How to choose pipes for water supply. Professional Tips:

When buying a pipe for a water supply system, the user most often has to choose the optimal ratio between the affordable price and acceptable quality. Often the choice is leaning towards the economics of the project. But among the cheaper offers, you need to carefully study the properties of the product and weigh all the arguments.

If doubts remain, then the advice of an experienced specialist will help determine which pipes are best to choose for water supply, how to avoid common mistakes.

Have you ever had to change the water supply in an apartment or a private house? Or maybe there is valuable information that you can share with our readers? Please leave your comments in the box below.

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Visitors Comments
  1. Anton

    No matter how much steel or plastic pipes are touted for their comparative cheapness, I want to say that copper is the most optimal material. Only copper pipes for water supply guarantee the greatest durability during operation. I work in the housing and utilities sector, and I can say with confidence that only they break down less often than others and do not bring as many problems as steel pipes.

    • Expert
      Nikolay Fedorenko

      Hello. “They break less often than others” - can pipes leak, burst, but break? The cost of copper pipes, fittings and soldering, not everyone can afford it. Even wealthy people install them in prominent places, and in a hidden system they combine them with more budget ones.

  2. Correctly noted - copper pipes are good in every way. But they are too expensive a pleasure, therefore for internal works I choose plastic pipes. They are easier to stack than galvanized, they look quite aesthetically pleasing. For outdoor work I take metal-plastic - we have frosts of 30-40 and ordinary plastic quickly fails. And I’ve already had such for 15 years.

  3. Andrew

    I wonder if anyone else uses steel pipes for internal wiring in a house or apartment? Here the question is not even the cost of the material itself, or its sanitary qualities, you just need to compare the installation process of steel and plastic pipelines. Steel is welding, pipe benders, subsequent painting.
    Polypropylene is mounted in white gloves, without smoke and dust. A soldering iron costs from 700 rubles, and no more tools are needed. If there are no scissors for the pipe and special stripping, then all this can be done with improvised means - a hacksaw and sandpaper. Well, aesthetics, after completing work, is incomparable.

    • Expert
      Nikolay Fedorenko

      Of course use why not.True, in most cases, these are pipes from the Soviet era. Change to steel is now extremely rare.