Coupling for pipes: types and features

When repairing an existing pipeline or laying a new one, the question of "how to connect the components" arises very often. This question is really important, as an unreliable connection may cause problems over time, and even a serious accident. In many cases, a pipe coupling can be a reliable connecting element. You will learn from this article, how to choose this product yourself, based on the characteristics of the pipeline.

Installation of pipelines is carried out by means of various types of couplings, which are selected according to the size and type of pipes

What is a clutch

Pipe couplings often look like a small cylinder, in which the ends of pipes are fixed in a certain way, which need to be connected. The method of installation depends on the specifics of the fitting. Couplings can be used as a simple connection between two sections of pipeline, and as an adapter. With the help of special types of fittings, you can connect the components of the line of different material or different diameters. If you follow the instructions during installation, the couplings can ensure high reliability of the pipe joints.

Advantages of couplings

Couplings have the following advantages:

• low price;
• relatively quick and easy installation in most cases;
• durability;
• reliability;
• availability and wide range;
• the possibility of rapid disassembly of the structure (subject to threaded connection).

Types of couplings

The fittings considered by us are issued for the following types of pipes:

• metal-polymer;
• polypropylene;
• polyethylene;
• plastic;
• cast iron, copper;
• steel.

A wide range of couplings is available for each type of pipe

Importantly! When installing the fitting, it is strongly recommended to choose a coupling, the material of which coincides with the material of the pipeline. When installing a coupling made of another material, the reliability of the joint can be significantly reduced.

Metal-polymer coupling

In the case of metal-polymer pipelines, pipe couplings are not particularly common fittings due to their uselessness. They are designed to connect short elements of the future network. Pipes made of this material rarely need additional connections, as most often blanks of the necessary length are bought at once.

However, an "adapter" fitting can be useful., which connects the metal-plastic pipe to the valve or steel pipe. If you change the plumbing in the house to metal, then the connection to the valves will be provided by just such a coupling.

Features of installation

The following steps are required to install this product.

1. Sealing. The external thread should be wrapped clockwise with flax. It is desirable to impregnate the flax or drying oil, or lead red lead. But, if these substances are not at hand, you can use any paint.
2. Careful, without exerting much force, it is necessary to turn the adapter on the previously sealed external thread. It is recommended to use an adjustable wrench for this purpose, so as not to scratch the material.
3. You need to put a cap nut on the pipe, and after - a cutting ring. The chamfer should also be removed from the inside of the pipe.
4. It is necessary to throw a pipe on the coupling union. Then two keys are used. The first fitting is kept in a stable position, the second - the pressure nut is tightened. Care should be taken in this step, so as not to move the seals.

Metal-polymer coupling allows you to quickly and easily connect metal and metal-plastic pipes

If you still need to connect two sections of plastic pipe with a regular pipe coupling, installation should be carried out in the same way. The only difference is the thread difference.

The sizes of similar fittings are selected according to the sizes of a pipe. So, the most commonly used sizes in 16, 20, 26 and 32 mm.

Polypropylene couplings

Fittings for this type of pipeline are a very simple design. It's just a piece of thick-walled pipe, which has a diameter, slightly larger than the diameter of the connecting pipe. At the same time the pipe in the coupling "does not walk", on the contrary - to insert it into the coupling, some effort is needed.

Installation

Installation is as follows:

1. First of all it is necessary to remove chamfers: external from a pipe and internal from the coupling.
2. If possible, you should set the temperature on the soldering iron close 270 degrees. Next you need to install the nozzle, which corresponds to the diameters of the fused products.
3. If the pipe has aluminum reinforcement, then it needs to be cleaned.
4. Next, you need to put the fitting on the narrow part of the nozzle, and insert the pipe into the wide one. You need to keep them 5-10 seconds. It is not recommended to press on the parts during soldering and keep them on the soldering iron longer.
5. Finally, remove the parts from the soldering iron and insert the pipe into the coupling.

Importantly! The pipe must be inserted directly, without turning. Otherwise, waves may form on the surface, which can greatly reduce the reliability of the connection.

The polypropylene coupling is mounted on the end of the pipe melted by a special soldering iron

Polyethylene couplings

Fittings for polyethylene pipes are divided into the following types:

• compression;
• electric;
• protective.

Each type implies its own method of installation.

Pipes of the same diameter can be connected with compression couplings for pipelines, and different. in addition, there are special fittings, which have an internal or external thread for connection to steel pipes, valves or other products, having a thread. So, this type of connector is universal.

Installation in this case is quite simple.

1. First, the fitting itself is partially disassembled, at half a turn the pressure nut weakens.
2. The pipe is cleaned of dust, the outer chamfer is cut with a knife or chamfer.
3. Depth is noted on a pipe, on which it must enter the fitting.
4. Insert the pipe into the coupling to the mark.
5. Tighten the tension nut completely.

Though, that the nut must be tightened completely, do not make excessive efforts in this process. Otherwise, you may damage the connector.

Wrinkle! For, so that the pipe fits better into the coupling, it is recommended to lubricate with liquid soap.

Electric couplings are used to connect polyethylene pipes

The electrical coupling is a connector, inside which is the heating element. Installation in this case is also quite simple. You only need to have a power source - a special device.

The installation is performed as follows:

1. Clean the pipe of dust and remove the top layer of polyethylene at the installation site.
2. Install the connector on the pipe.
3. Apply power to the fitting terminals.
4. Disconnect the wires after heating.
5. Leave the design on 20 minutes.

Thanks to the heating element, polyethylene components melt. When the power is turned off, they harden and form an almost monolithic and very reliable connection.

Protective couplings are used in the case of laying the pipeline through reinforced concrete walls. Constant contact with reinforced concrete can adversely affect polyethylene, therefore, it is recommended to use such protection. The coupling is an integral ring, which is installed in the wall. A pipeline should be routed through this ring. Having established similar protection, you can not worry about the impact of reinforced concrete on polyethylene.

Plastic couplings

Plastic couplings are very easy to install. They are a cylinder with two seals, it is sometimes called "connecting pipe". For installation, simply remove the outer chamfers from the pipes and connect them to the fitting.

Plastic couplings are very easy to use, they put on pipes without the use of tools

Wrinkle! If for some reason you think, that the connection is not secure enough, you can walk on the seams with sealant.

Cast iron and copper couplings

There are special fittings for connecting this type of pipeline, but installation in this case is rather difficult. Firstly, be sure to be able to approach the pipe from each side, otherwise it is unrealistic to ensure the tightness of the joint. If the pipeline is laid near the wall, you will have to dig a part of it near the joint. Secondly, all work must be done very carefully and focused. Extremely desirable, that the installation was done by an experienced man, as such work may not be possible for a beginner.

Installation is as follows.

1. First, the joint is sealed with a bobbin.
2. The pipe is inserted into the fitting as far as it will go. This is necessary for that, so that the seal does not fail.
3. Coinage is minted. It is necessary to make some turns and each turn to mint on all circle.
4. After stamping it is necessary to cover a joint with a cement solution.

You can mint with a simple screwdriver.

Importantly! Do not neglect the stamping of the seal. If you limit yourself to cement mortar, the connection will not last long. After a while, it may leak.

Steel couplings

Steel couplings are very popular. They can be used to connect pipeline components, and to eliminate fistulas, cracks and other similar damage.

Steel couplings can be used not only for pipeline installation, but also for its repair

These products are divided into two types: threaded and compression.

Threaded fittings

Threaded connectors are the simplest cylinder, having a thread. By means of this carving also components of the pipeline are fixed. The fitting provides high reliability, and at installation it is possible not to be afraid to damage a product - it is rather steady against mechanical influences. The disadvantage of such parts is one - if they are used on cold water, over time, under the influence of condensate, the threads stick to each other, which will greatly complicate possible disassembly in the future. To avoid such consequences fittings are made of cast iron or brass - they are not susceptible to such phenomena. Installation is simple - just screw two sections of pipe into the connector thread.

It happens, that during installation and disassembly it is not possible to rotate the pipe. In this case, use special couplings with theft.

Such connections are installed in the following steps.

1. The locknut and the coupling must be screwed on a long thread of theft.
2. The short thread must be screwed into the coupling valve, another fitting, etc.. P. Wrap the connection with linen.
3. Next, you need to wind the outer thread of the pipe from the side of the long thread of theft.
4. It is necessary to bend on a pipe the coupling on a long thread of theft.
5. After the coupling the locknut is driven away. Here, too, it is necessary to wrap the connection with linen.

This results in a reliable and durable connection of the steel pipeline.

Compression fittings

Such connectors are a universal solution in those cases, when there is no thread on the pipe, or it has rotted, or cut it is impractical. Properly installed, such fittings will ensure a high tightness of the connection.

Compression couplings are installed in those cases, when it is not possible to use a threaded fitting

As with other pipe couplings, there are many types of compression parts, which allows you to use the fitting as an adapter from one diameter or material to another. in addition, compression steel connectors can be threaded on one side to connect the valves, threaded pipes, etc.. d.

Such fittings are also often called Gebo.

Installation in this case is carried out quickly enough. Another advantage of such products is that the connection is easy to disassemble at any time.

They are installed as follows.

1. You need to cut the thread from the pipe (for cases, when the thread is damaged and a threaded fitting cannot be used).
2. Clean the area of ​​the pipe at the intended joint from paint and other.
3. Then put on the details of the fitting in this order: push nut (per pipe), crimp ring (cone to nut), clamping metal ring rubber ring (cone from the nut), clutch housing (per pipe). It is not necessary to press a pipe into a fitting up to the stop, it is better to leave a small stock - about 5 mm.
4. Tighten the cap nut. Hold the connector housing with one key, and others to tighten the nuts.

After installation it is necessary to check up, whether it leaks or the joint. If this happened - then, the surface was poorly cleaned and there is no tightness in this joint.

Such connections are very useful when repairing old pipelines. The point is, that welding in this case may be a short-lived solution: as a result of welding, the fault may appear elsewhere.

Wrinkle! Most of the compounds we have considered can be used multiple times (except polypropylene and electric polyethylene). When dismantling, do not rush to throw them away - they may still be useful. However, be sure to replace the rubber seal, if he is. If you reinstall it, the reliability of the connection is not guaranteed.

So, pipe coupling - a universal and very convenient tool for connecting all types of pipes and creating various transitions to other diameters or materials.