Plumbing coupling - types and features

14-02-2018

Pipes

In most cases, the connection of water pipes is carried out using a coupling. This fitting performs an important function - it provides a tight installation of pipeline elements. Below we consider what types of couplings exist, the features of their installation, as well as the main functions that they can perform.

General information

A classic coupling is a short tube whose inner diameter corresponds to the outer diameter of the pipes being joined. Such fittings can be used both in monolithic and collapsible pipelines.

It should be noted that the material of the part can be any, the only requirement is that it must be the same as the material of the pipeline. Below we take a closer look at the various types of these products.

Mounting methods

The main difference of the products under consideration is the method of their installation.

By this parameter, they are distinguished by the following types:

Threaded;
Welded plastic;
Crimp;
Compression.

Threaded

As a rule, threaded fittings are used for steel pipelines.

Instructions for their connection using this coupling is as follows:

First of all, it is necessary to cut the connected pipes strictly perpendicular to the axis.
Then the thread is cut into the part.
Further tighten the nuts.
After that, the pipes are in turn screwed into the connecting piece.
At the end of work tightened the clamping nuts.

This work is completed.

Welded

As a rule, the welded method install plastic couplings for water supply. Moreover, depending on the type of plastic, the process of assembling the water supply system may vary:

Polypropylene	Welding (soldering) of the fitting is as follows: The pipe and fitting are inserted into the heated nozzles of a special soldering iron. After softening the plastic surface, the parts are pulled out of the soldering iron and are connected to each other. After cooling of the plastic, the second pipe also connects to the fitting.
PVC	The method of installation of PVC pipelines is more like gluing, not welding. However, the joined surfaces under the influence of chemical composition (glue) melt and weld. Therefore, it can also be attributed to welding. Installation is carried out in this order: The joined pipe is cut, after which it is inserted into the connecting part. Then you need to make a mark on how deep it goes into the part. Further, the marked-up area is smeared with a brush with a special adhesive using a brush. After that, the elements are connected and rotated a quarter turn. After a few minutes, the second pipe is glued in the same way.
HDPE	As a rule, the installation of HDPE plumbing is carried out using an electric-welded coupling, which has electric spirals. After joining all the parts, a special device is connected to the electrofusion that supplies electricity to the spiral. As a result of the heating of the spiral, the parts are welded together.

Tip! The price of welding machines for plastic pipes is quite high. Therefore, for a one-time installation of water supply it is more expedient to hire equipment.

Crimp

Crimp couplings for plumbing apply to metal-plastic systems. It should be noted that the need for them arises extremely rarely, since “metal-plastic” is sold in bays, which are tens of meters long.

However, if the need for matching nevertheless arises, the crimp element is installed as follows:

As in the previous cases, the joints should be cut at a right angle;
Then the tubes are inserted into the sleeves;
After that the junction is crimped with a special tool.

Compression

Compression fittings exist for PVC and metal-plastic pipelines. Their main advantage is that their installation does not require special equipment.

It is carried out as follows:

The fastener parts are put on the tube - nut, collet ring, etc.
Next, the pipe is put on the fitting or inserted into the pipe fittings.
After this, the collet ring is pulled in and the nut is tightened.

Note! When installing compression fittings do not strongly tighten the nut, this is especially true of plastic pipes. Otherwise the pipe may crack.

This process is complete.

Purpose

As we found out, the main purpose of the products in question is to connect the pipes during the assembly of the pipeline. However, in addition, some of their species can perform additional functions.

These include the following fittings:

For a conclusion of the thermal pipeline - provides a tight conclusion of a wire outside. Accordingly, the coupling for taking the heat pipe out of the plumbing has rubber seals that compress the wire.

For tapping under pressure - are used in the case when it is not possible to block the water supply. The coupling for tapping into the water supply under pressure has a clamp-type fastener, which is put on the main line and a locking device that blocks the flow of water. Drilling line is carried out after installing the clamp.

Fire couplings for plumbing provide passive fire protection of housing. These products, in fact, represent a steel casing, which is installed on the pipe.

As a rule, fire protection couplings are installed on the risers of the water supply system, at the places of its passage through the ceiling, as well as on the wiring, in the area of the passage through the walls.

Here, perhaps, are all the most common types of fittings under consideration, which are used in plumbing.

Conclusion

Couplings are used in almost all types of water pipes. Most of them are designed to connect pipes together, however, there are fittings that perform other equally important functions.

From the video in this article can be found with some additional information on this topic.