Copper pipes and fittings: types, markings, features of copper pipeline arrangement
Despite the popularity of metal-plastic and polypropylene, copper pipes and fittings are widely used for the installation of heating and water supply networks. They are considered the best option for equipping refrigeration equipment and air conditioners.
We will try to understand the variety of copper products and find out which methods of connecting pipes are the most effective.
The content of the article:
Copper pipes for internal wiring
Unlike metal-plastic analogues, copper pipelines have minimal thermal expansion, do not deform over a long period and do not react to sunlight. They can be installed in winter and summer - the technical characteristics of copper do not change due to exposure to low temperatures.
All types of home communications are constructed from copper pipes:
We offer information that may be useful when choosing or installing copper pipe material.
Varieties: insulated and non-insulated
We are used to seeing uninsulated copper pipelines - metal networks of a reddish tint, assembled using fittings made of copper, bronze or brass, sometimes soldered or connected using a welded coupling method.
Domestic and foreign manufacturers offer products that differ not only in size, section shape or manufacturing method, but also in external design.
Thus, among copper pipes you can find the following types of pipes:
- non-insulated for installation of intra-house networks and assembly of gas and electrical equipment;
- with PVC insulation for protection against corrosion and mechanical damage;
- with elastic polyethylene insulation for water supply systems;
- with polyurethane foam insulation for networks with maximum heat-saving requirements;
- with protective insulation for underfloor heating and complex systems.
To connect copper pipes with insulation, fittings without insulation are used, and the installation methods do not differ from conventional ones.
How to understand the markings?
In order not to make a mistake when purchasing pipes for self-installation, you need to learn to read markings and color marks.
The production of domestic brands of pipes is carried out in accordance with GOST 617-90, the section of which is called “Copper Pipes”.
The marking is applied according to a general scheme and contains the following information:
- manufacturing method (drawn, cold rolled - D, pressed - D);
- cross-section (round - KR);
- manufacturing accuracy (normal - N, increased - P);
- condition (from soft - M to hard industrial strength - H);
- length (unmeasured - ND, multiple of measured - KD, in coils - BT);
- special conditions.
Special conditions include designations of products of increased length or high accuracy in curvature and length.
The marking sample GKRPT 32*3*5000 M3 is deciphered as follows: pressed solid round section of increased manufacturing precision, with an external cross-section of 32 mm, a wall thickness of 3 mm, a measured length of 5 m, made of MZ grade copper.
In addition to the GOST marking, a designation system according to the international standard NF is used: the country, manufacturer, plant number, and standard size must be indicated.
Assortment and selection conditions
Soft copper pipes of small cross-section are sold in coils of 25 m and 50 m, and large-diameter products are sold in pieces of measured length, most often 3-5 m. The so-called “soft” types, widely used for floor heating, are rolled into coils.
In the installation of copper pipelines, three types are used, differing in degree of hardness:
The thin cord bends easily and does not require the installation of fittings or other elements that ensure the installation of rigid-type pipeline bends.
To determine the parameters or characteristics of pipe materials of various sections, tables are used.
Some types of pipes are in high demand. For example, for water supply systems, products from 12 mm to 22 mm in diameter are used, and for drainage systems - from 32 mm and above.
In addition to the external cross-section, it is customary to indicate the wall thickness or internal diameter (let’s say 12/2 or 12/14 is a pipe with an external diameter of 14 mm, an internal diameter of 12 mm and a wall thickness of 2 mm).
Types of Copper Pipe Fittings
Fittings are necessary when assembling pipelines to create reliable detachable and permanent connections. The result of a properly made connection is the operation of the network without repair for 15 years or more. Let's look at what types of fittings are used for copper pipes.
Option #1 - compression
Soldering is not used to install compression fittings. Collet structures are called conditionally detachable, since they create a sealed connection that needs tightening from time to time. In this regard, pipelines cannot be sewn into the floor or walls.
To install a compression fitting, no special tool - pliers or clamps - is needed. First, crimping is done manually, and then the union nut is tightened with an adjustable or open-end wrench.
It is recommended to use a pair of keys: one to hold the body, the other to perform semi-rotational movements. For a strong connection, 2-3 additional turns are usually enough.
Push-in fittings have standard dimensions - according to the cross-section of the pipes, and their inner wall is pre-calibrated (for making a socket connection). In addition, they differ in purpose.Let's assume that parts for the plumbing and heating systems may differ in design.
Option #2 - press fittings
Compression fittings have a completely different design. They have a tubular structure, and each end is equipped with a recess with a seal. The principle of mounting on a pipe is based on one of the qualities of copper as soft and pliable when processing metal.
During the crimping process, the design of the part is deformed in such a way that the material with the sealing ring creates a permanent, hermetically sealed connection.
To assemble a pipeline using press fittings, you need a special tool - press pliers.For temporary and one-time work, a manual device is suitable, but with constant professional use it will quickly cause fatigue.
For qualified plumbers, hydraulic and electromechanical models are available - expensive, but saving energy and time.
The difficulty of pressing is that after crimping it is sometimes difficult to distinguish a processed fitting from one simply put on the pipe. To avoid any omissions, manufacturers have equipped the parts with special signal elements that change their appearance after crimping: bright plastic rings or deformable bulges called SC-Contur.
It is not difficult to distinguish parts by purpose, since they are marked with a marker of different colors:
- blue or red – water supply (drinkable or non-drinkable);
- green – heating;
- yellow – gas supply.
There are also universal options: for example, yellow-blue markings indicate that the fittings can be used in systems for moving gases and water. Color is also used to mark the seal (yellow for gas, black for water, etc.)
Option #3 - for soldering
Soldering provides a strong and permanent connection between two pipe fragments. This is done using a special tool. Immediately before soldering, the ends of the pipes are overlapped, that is, a socket joint is used.
However, there should be a small gap between the walls, which is necessary for filling with molten solder. The gap size is from 0.02 mm to 0.4 mm.
The main tool for soldering is burner, but for the primary processing of pipes they also use a calibrator (expander), a chamfer, a pipe cutter and all kinds of cleaning tools (brushes, sandpapers).
A hand burner with a 200 ml gas cartridge is suitable for home use. A lightweight and convenient hand-held device produces a flame with a temperature of + 1100 °C, which is quite enough to melt soft solder.
You will also need a flux solution that is used to lubricate the connecting parts of the fitting and pipe.
The surface of copper parts is coated with flux using a brush. It ensures uniform spreading of solder over the joint area.
For self-soldering, low-temperature technology is usually used. Fittings for this type of welding are equipped with a strip of soft solder, which is placed in a special encircling groove.
The high-temperature welding method is used in production and when creating industrial networks.Distinctive features are the use of hard solder, and further the ability to move gases and liquids under high pressure. For more information on how copper pipes are soldered, read this material.
How is capillary soldering with a fitting performed?
Before starting work, you should prepare the following tools and materials:
- gas burner;
- flux;
- solder;
- pipe cutter;
- chamfer;
- brush and fine sandpaper.
Procedure:
After the tin solder cools, a strong connection is formed, ensuring 100% tightness. The soldering process without a fitting is carried out according to the same scheme, but with the only difference: instead of the connecting element, the end of the second pipe is processed, overlapped on top. The gap between the pipes is filled with molten solder in the same way.
Instructions for pressing copper pipes
The only tool required for the pressing procedure is press jaws. Before starting work, prepare pipe sections according to the instructions given above.
Step-by-step instructions:
We remind you that crimping creates a maintenance-free connection that lasts up to 30 years or more. The finished pipeline can be laid in grooves, covered with plasterboard or filled with screed.
There are a number of nuances, knowledge of which will help you cope with pressing copper fittings yourself, even if you are doing this for the first time.
When crimping by hand, try not to use excessive force so as not to deform the pipes.
The choice of fittings depends on many reasons, including your skills. If your skills are not enough, then you shouldn’t take up the torch, but make a crimped or pressed connection that even beginners can do.
We also recommend reading our other articles, where we examined in detail the types of copper pipes:
2. Water pipes made of copper.
Conclusions and useful video on the topic
While watching the videos, you can see technical nuances that are difficult to imagine when reading the article.
Video instructions for pressing a gas pipeline:
Video review of copper fittings for various purposes:
How copper pipes and fittings are made:
The entire soldering process in one video:
The connection of copper pipes into one system is carried out by analogy with steel and metal-plastic products, but with the use of special fittings - brass, copper and bronze.
If you master pressing technology or a more complex soldering method, you will be able to install a heating network or water supply system yourself. But keep in mind that copper communications are very expensive!
Please write your comments on the topic of the article in the block below. Perhaps you know the nuances that we did not mention in this article? Share them with other site visitors.
12/14 - wall thickness is 1 mm, not 2.
I don’t even know who can afford copper pipelines; non-ferrous metal itself is very expensive. And the shaped parts and fittings are several times higher than the cost of other materials. During my practice, I soldered copper only twice, nothing particularly difficult. But this is such painstaking work, slow and boring.
During the time it takes to solder one connection, you can solder the 4-point polypropylene wiring. Copper is relevant only for radiators, and there the volumes are completely different.
Yes, copper is relatively expensive, but copper piping is far from uncommon. I know many examples when people in newly built cottages prefer copper to other materials.Durable, flexible, easy to install - copper pipes have many advantages.