Dielectric insert for gas: types of gas couplings and installation tips

Connection of gas appliances connected to power supply takes into account three criteria: reliability, safety for users and equipment, long service life. To ensure that gas water heaters, boilers, convectors or stoves operate without interruption, a dielectric gas insert is used - a small polymer insulator mounted in a pipe.

If you decide to connect gas equipment yourself, we recommend installing a dielectric. You can learn from this article why it is needed, what types it is divided into and how it is installed.

Purpose of the electrical insulating insert

First, let's find out why an insulating dielectric coupling for gas is needed and how it works.

The main function of the dielectric is to protect equipment from stray currents that can arise in the gas pipeline for various reasons. Is stray current so dangerous and are there any ways to prevent its occurrence?

It appears in the ground at the moment when an accident occurs on power lines, railways, or tram tracks. Due to the difference in the characteristics of the conductors - the earth and the metal structures of the gas lines, the current is transmitted to the gas system.

Where natural gas pipelines pass, apartment buildings are traditionally equipped with gas stoves. If the column or stove is installed incorrectly, stray current can penetrate into any apartment in a high-rise building

The actions of illiterate neighbors who are in no hurry to replace faulty electrical wiring or simply ground electrical appliances to pipes or batteries can also pose a danger.

Here's what will happen if stray currents reach your gas equipment:

• gas appliances, most of whose parts are made of conductive metal parts, become unusable and themselves become sources of danger;
• when an accidental spark occurs, there is a risk of fire, which becomes thousands of times more dangerous in a gas environment. A fire can cause an explosion, and for an apartment building this is a real disaster;
• stray currents transmitted to household appliances and pipes during a thunderstorm or power failure can cause serious injury to the user of gas equipment.

To maintain your health and anticipate any risks, use a dielectric coupling on the gas pipe.

One of the advantages of dielectric is simple installation. You can install the insulator yourself, but the tightness of the joints and control are checked by gas service employees

Now inserting a dielectric insert into a pipe has become mandatory for everyone who installs gas appliances in a house or apartment, while the functions and characteristics of the equipment do not matter.

Installation of insulating inserts is regulated by law - in paragraph 6.4 SP 42-101-2003 it is said that immediately after the shut-off valve a dielectric should be installed in order to exclude the presence of leakage currents, equalizing currents and short circuits to the housing in the gas pipeline. True, there is a caveat - the function of an insulating insert can also be performed by a flexible hose that does not conduct electric current.

Types of dielectric cut-offs

In everyday life, two types of dielectrics are used for gas hose or pipes: simple bushings resembling liners and threaded couplings. Let's look at how the inserts differ and choose the best solution for self-installation.

Option #1 – bushings

Let's say right away that for gas stove installation or column installation You won't need bushings, as they have a slightly different purpose. The task is the same - to protect against stray currents.

But they are mounted where there are flange connections and bolts are used. Simply put, bushings are used for electrical insulation of flange fasteners.

In appearance, bushings for gas equipment can be confused with other insulators - for various equipment: radio-controlled cars, agricultural vehicles, car steering columns, etc.

Dielectric inserts are made of polyamide PA-6. They are resistant to external influences and have a long service life.

Technical characteristics of gas bushings:

• frost resistance - can withstand low temperatures down to -60 ° C;
• elasticity and high degree of adhesion to metal elements;
• petrol and oil resistance at temperatures up to +120 °C;
• ability to withstand multiple alternating loads.

Products are marked by diameter in mm, for example, from M 8 to M 24. The manufacturer indicates the diameters of suitable flanges, bolts, and washers in special tables. There you can also specify the height of the collar and the length of the bushings.

Option #2 – couplings

Universal insulating inserts for gas pipes are connected using the coupling method, which is why installers often call them couplings.

They differ in the type of thread, diameter, material of manufacture, external design, but still perform the same function - they cut off the currents generated on gas pipe, from equipment.

Modern gas boilers are equipped with electronics that are powered by electricity. The impact of stray currents can instantly disable the “brains” of the boiler, which will result in expensive repairs

Inserts are manufactured in the factory according to GOST or TU. They are produced in special molds in an automatic way, using screw extrusion of two materials: an insulating polymer and metal for threaded pipes. Polymer material meets the requirements GOST 28157-89.

The products are intended for operation at a working pressure of 0.6 MPa; the critical value is 1.2 MPa. The average operating temperature is from -20 °C to +80 °C.

By GOST 14202-69 gas inserts belong to group 4 (flammable gases) and are marked yellow, but products with a black polyamide part can also be found on sale.

The brand name and diameter are also marked on the surface of the insulating element. For household use, dielectrics are produced 1/2″, 3/4″ - DN15, DN20, respectively

It is better to purchase products from well-known brands rather than Chinese counterfeits, and choose products based on the following criteria:

• fire safety – threaded metal elements do not burn, and plastic ones do not support combustion;
• wear resistance and durability – high-quality parts are made of brass and have a 20-year service life;
• suitable technical specifications – resistance of at least 5 Ohms with a sharp increase in voltage to 1000 V.

The best place to install the coupling is between gas tap and flexible liner.

The connection method is threaded, made by screwing the device onto a pipe. The fittings can have both external and internal threads.

Sample of a tap with an insulating coupling. A combination of products from one manufacturer simplifies the installation of the dielectric and makes it faster. The device is installed at the end of the pipe, before connecting the hose leading to the stove or boiler

Before purchasing a dielectric, it is necessary to clarify the diameter of the gas pipe, as well as select a flexible hose that is suitable in size. Sometimes connection hoses are sold with the equipment, so be sure to check the package.

The gas insulator is installed for a long time and does not require maintenance, but is constantly under the control of the gas service, which inspects the equipment annually.

The procedure for installing a dielectric on gas

Before any work on gas equipment or lines, it is necessary to turn off the tap to stop the flow of fuel and ensure safety. If the stove, heater or boiler was used before, you need to leave the burners in working order so that the remaining gas burns out.

Then we proceed in order:

1. If the flexible line is already attached to the pipe, use a wrench to carefully twist the nut. Fasteners that have been installed for a long time often “stick”, so to be sure, you can use two keys.
2. We wrap a sealant - fum tape - around the free end of the pipe and carefully tighten the connection, first by hand and then with a wrench. We screw the coupling or “barrel” as far as possible, being careful not to knock off the threads or deform the dielectric body.
3. In the same way, screw the flexible line nut onto the other end.
4. We diagnose the connection in a safe way.

A soap solution is used not only by users of gas equipment, but also by Gorgaz employees to check the tightness of connections. Diagnostics is simple: apply soap foam with a shaving brush or brush to the joints and observe what happens.

The appearance of bubbles, even small ones, indicates a lack of tightness - the coupling will have to be tightened. If there are no bubbles, the installation was completed correctly and you can safely use the equipment.

It is prohibited to use open flames such as matches or lighters to check for gas leaks.

Step-by-step instructions:

We remind you that you cannot use gas appliances until a gas service employee arrives. He must carry out verification, record the fact of installation of the dielectric and give permission to operate the connected equipment.

And in the future, carry out all activities related to connecting, replacing, and repairing gas equipment together with representatives of the service organization.

Conclusions and useful video on the topic

How to install a dielectric into a faucet in practice:

The sequence of connecting the column to the gas pipeline:

Now you know how to correctly and quickly install a dielectric insert for gas on a pipe. The installation procedure can be carried out independently or by a specialist - in any case, the result will be your safety and the serviceability of your home gas equipment. If you still don’t have a dielectric, we recommend installing it, and at the same time changing the gas hose, which has a limited service life.

If you have had to deal with installing a dielectric on a gas pipe, please share your experience with visitors to our site. Leave your comments, ask questions to experts and participate in the discussion of the material. The communication block is located under the article.