Pipes

Coupling for metal-plastic pipes. Types of connections

April 6, 2020

Pipe connections are an integral part of the process of designing and installing pipelines for various functional purposes. Various fittings are used for this purpose, which include couplings. They have one of the main roles in the operation of networks. After all, there are bends in any highway, and therefore utilities without couplings will not function effectively. And it doesn't matter, which type of pipeline is metal or polymer.

Metal-plastic pipes are connected with different types of fittings, installation of which has its own characteristics

Types of connections

In general, fasteners are classified according to a number of basic characteristics. Depending on the function performed, fittings are available:

  • cruciform - used to organize the diversion of two branches from the main highway of the system;
  • fittings - provide the ability to connect metal-plastic products with flexible hoses;
  • angular - change the direction of the pipeline at a certain angle - 90, 45 or 120 degrees;
  • tees - are used for the organization of one branch from the main pipe of the mounted engineering communication;
  • muftovymi - with their help standard connection of pipe products is carried out, which are on the same line.

in addition, fittings are divided into direct and transient. The former are used to connect pipes with identical diameters. The second applies, when you need to change the intersection of the highway. However, there is a basic criterion, according to which fittings for installation of metal-plastic products are divided into three types - threaded, compression and press fittings.

What tool do you need to work with metal-plastic pipes. Types of couplings and their installation

It should be noted at once, that the use of such a fitting, as a clutch, metal-plastic pipelines are not widespread. The reason for this phenomenon lies in the fact, that metal-plastic pipes come to the end consumer in bays tens of meters long. Therefore, the connection of two elements, made of this material is irrelevant. After all, the performer can unwind a measuring segment of any required length from the bay.

To work with metal-plastic pipes and fittings to them, you need to have a set of special tools

And yet, it is sometimes necessary to solve the problem of connecting two metal-plastic pipes. Working with such products does not require welding or soldering, it is enough to have such a tool:

  • extensible, carob and socket wrenches;
  • cutter or pipe cutter (as a last resort, suitable hacksaw);
  • pipe bender;
  • calibrator;
  • press ticks;
  • expander;
  • scan.

The connection of metal-plastic pipe products is made by threaded and press couplings. In addition, compression fittings are used for this purpose. Let's consider each option in more detail.

Installation on a threaded coupling. The sequence of actions in this case looks like this:

  • trim the pipes.

Importantly! The plane of the cut must be strictly perpendicular to their longitudinal axis. This will ensure a perfect fit between the end of the pipe and the edge of the coupling.

  • disassemble the threaded fitting;
  • put the split rings on the pipes and tighten the nuts;
  • fit the first pipe to the coupling fitting, tightening the connection with a nut;
  • put the second pipe on the opposite fitting and also fix with a nut;
  • lock the coupling body with a sliding wrench and then, using a socket wrench, alternately tighten the first and second tightening nut. The work on the coupling connection of metal-plastic elements of the pipeline with a threaded coupling will be completed..

To clamp the press couplings use special pliers - manual or automatic

Installation on the press coupling. Compared with the threaded counterpart, crimp connection is much faster. Its implementation includes the following stages:

  • trim the joints, as in the previous version, strictly at right angles;
  • insert into the sleeve, available in the press coupling, to be connected to the pipe;
  • crimp the joint with a special tool.

Importantly! Perform compression on both ends of the coupling at the same time.

Installation on a compression fitting. Perform this work according to the following scheme:

  • cut pieces of pipe length of the required length. Align their ends with a calibrator. Clean the edges with a round file or a sharpener drill from burrs and roughness;
  • align the metal-plastic pipe. As a result of this operation you should get a straight straight section of length from 10 centimeters before and after the cut;
  • make a western chamfer at the ends of metal-plastic products up to 1 millimeters;
  • put on a pipe at first a cap nut and a cutting ring;
  • lubricate the fitting with silicone compound, then put the pipe product on it like this, so that its end rests with its entire plane at the edge, present on the connecting element;
  • tighten the nut all the way by hand, without applying the key. If twisting requires a lot of effort, means, the nut did not go on the thread. When you easily twist it all the way, do the following: hold the fitting housing with one wrench, and others tighten the nut no more than on 2 turnover. At the same time the split crimp sleeve is compressed on a metalplastic product, thereby ensuring the tightness of the connection between the pipe and the pipe.

Connection of metal-plastic pipes with products made of other materials

In real life, it may be necessary to upgrade an existing pipeline. In houses, built during the Soviet era, utilities were made of metal. And although today such products are also present on the market, experts recommend to stop the choice on more modern pipe products - metalplastic.

By means of transition couplings it is possible to replace a site of a metal pipe on metalplastic

Of course, it is inexpedient to change all pipeline - it is simply possible to replace its problem metal sites. But for this you need to know, how metal-plastic pipes are connected to the elements of the engineering network branch, made of other materials.

Connection with metal pipes. For this purpose the coupling coupling for metalplastic pipes is used, made of metal. The step-by-step instructions for this procedure look like this:

  • the end of the metal (old) clean the pipeline of rust and dirt;
  • screw on the clutch, using a wrench;
  • calibrate the product. Put a crimp ring and nut on it;
  • put a metal-plastic pipe on the free end of the coupling and tighten the nut.

Useful to know! Paint and rags can be useful in the work. Using them helps to create a tighter connection, which does not allow leakage.

Connections with polypropylene pipe elements. Usually, products of this type are used to connect gas columns, washing machines, boilers. In this case, the connection is performed using a special coupling-adapter. This detail has its own characteristics: part of the coupling on the other side, where a purely polymer pipe will be connected, made of polypropylene. The connection is made by soldering or welding. And here connection of a metalplastic pipe product is carried out to a metal part of a connecting detail by winding on a carving. That is, everything is simple and no additional comments are needed.

How cast iron pipes are connected

These products are used mainly in sewer systems. There are cast iron pipes on the market, as with the bell, and without him. They are labeled SME and SMU respectively. The tightness of the bell connections is ensured by a rubber gasket installed in the bell. Installation of smooth segments is performed using various cast iron fittings: couplings, leads, knees, tees, crosses, flanges, plugs and piping.

The connection of cast iron pipes is most often carried out by the bell method, but in this case the joint may require additional sealing

As for the couplings, then there are three types:

  1. Coupling cast iron coupling. This part is a cylinder with an internal thread. Used to connect two pipe products with the same diameter.
  2. Adapter. Design - two cylinders, on the inner surface of which there is a thread. It is intended for coupling connection of segments with various diameters.
  3. Futurka. Threaded cylinder on the outer and inner surfaces. Used to connect elements of heating systems.

The coupling for cast iron pipes may have a socket or a flange at the end. This makes it possible to use different types of pipe products when installing the system. The most reliable way to connect cast iron pipes with metal-plastic ones is to use a press fitting, one side of which is designed to be connected to a metal-polymer element, and the other has a metal thread.

Make the connection in the following sequence:

  • evenly trim the end of the old pipeline;
  • smear it with solid oil and cut the thread;
  • wipe the thread and wind the sealant on it. FUM-tape will be suitable for this purpose;
  • screw in the coupling.

Importantly! That it did not burst, wind your hand. If a leak appears after connecting the system, the coupling can be tightened.

Universal couplings can be used to connect a cast iron pipe to a pipe made of another material

Cast iron pipes are connected to steel pipes by means of branch pipes, at one end of which there is an adapter to steel, and on the other - a bell. Such details are different in weight and length.

The sequence of stages of accession is as follows:

  • insert the end of the old pipe into the socket;
  • cut a thread on the steel end;
  • wind FUM tape on it first, and then the coupling;
  • Screw the steel pipe product to the other end of the connector.

In the absence of leakage, it is possible to put the created branch of engineering communication into operation.

How to mount a cast iron coupling with chamfering joints

Embossing couplings have been used for more than a century. These parts are equipped with two bells, directed in opposite directions. Without some knowledge, it will not be possible to securely connect the pipe to the coupling. Therefore, we will dwell on this issue in more detail.

  1. To seal the joint, it is necessary to have access on all circle, as to the pipe, and to the coupling. When installing the sewer near the wall, part of the wall will have to dig out.
  2. A sealant must be used to prevent leakage. Organic fiber is suitable as such, impregnated with oil (T. zv. bondage). No worse the result will be obtained, when minting joints with graphite stuffing box.
  3. So that the seal simply does not fall inside, the pipe is inserted into the coupling as far as it will go.
  4. Mince should be minted in several turns. And each of them must be sealed around the circumference of the tubular element.

In the absence of a special tool for minting at hand, home builders offer such a solution: use a wide screwdriver or a steel ton tube with a flattened end.

After sealing, the joint must be covered with cement mortar.

Carefully considering and studying all existing options for connecting metal-plastic and cast iron pipes using couplings and fittings, you will be able to easily correct the abnormal situation in your water supply and sewerage system and even repair the pipeline with your own hands.