Dielectric insert(or - permanent connection that prevents the spread of leakage currents. The dielectric insert also protects electronic components (for example, control units) and electrical circuits (for example, electric ignition system, lighting) of gas-consuming equipment from the harmful effects of stray currents. The insert is installed between the gas tap and the gas supply. Of course, the gas meter can also suffer from stray currents. And, importantly, the insulating insert eliminates possible heating and even sparking of the metal gas line as a result of the accumulation of electrical potential on it.
There are several reasons for the occurrence of stray currents, or leakage currents. The main ones are:
-Damage to the insulator on the gas main. On steel pipes main gas pipelines To prevent corrosion, a small electrical potential is specially supplied, which must be extinguished at the entrance to the apartment house or at the outlet from the gas distribution unit in the immediate vicinity of the outlet to individual home. For these purposes, a special main dielectric insert is used. In case of its destruction or absence, the electrical potential freely penetrates into the intra-house and intra-apartment gas pipelines.
-Lack of electrical grounding, faulty wiring and 
local electrical circuits. Modern gas consuming appliances ( gas boilers and water heaters, stoves, ovens etc.) are often crammed with electronics and local electrical circuits. These include electronic control modules, electric ignition, timers, lighting systems, etc. In the absence of the necessary electrical grounding, as well as when electricity enters the metal body of the equipment due to a malfunction of local electrical circuits (the so-called ground fault), such equipment itself becomes a source of harmful currents.
-Illegal grounding of electrical appliances on gas steel pipes. Often your neighbors, who have entrusted the work of connecting certain electrical appliances to “craftsmen,” are blissfully unaware of the fact that their (neighboring) electrical appliances are grounded to a gas pipe.
SPECIFICATIONS:
Connection dimensions insulating inserts: 1/2", 3/4";
Execution option: fitting-fitting;
Material of metal parts: brass CW614N according to EN12165, analogue of sanitary brass LS59-1 according to GOST 15527;
Dielectric: Polyamide according to GOST 14202-69 with fire resistance category PV-0 according to GOST 28157-89;
Nominal pressure PN=6 Bar (or about 6 atm). For reference: according to SNIP 2.04.08-87, in intra-house and intra-apartment gas pipelines, gas pressure up to 0.03 atm is considered normal;
A conversion table for pressure units is available on our website.
Electrical resistance: more than 5 MOhm at U=1000V;
Operating temperature range: from -60 to +100 degrees. Celsius.
The use of an insulating insert is regulated by MOSGAZ Letter No. 01-21/425 dated December 26, 2008: “...When connecting gas stoves to a flexible connection, provide a dielectric insert.”
Dielectric insert:
Goods ordered in the OBI online store are delivered throughout Moscow and the Moscow region within 50 km from the Moscow Ring Road. Delivery costs are automatically calculated when placing an online order, based on the weight of the product and delivery area.
Minimum order amount for free delivery:
We will deliver your order free of charge if the delivery address is located in the first delivery zone for online orders, and also:
- > 5,000.00 RUR- for orders weighing up to 5.0 kg
- > 10,000.00 RUR- for orders weighing up to 30.0 kg
The courier service delivers small-sized orders (weighing up to 30 kg) to the buyer’s door, large-sized ones - to the entrance (wicket, gate) of the house. Delivery includes free unloading of goods from the vehicle and their transfer within 10 m.
Delivery date and time
Next day delivery is available when ordering before 6:00 pm. You will be offered a choice of one of two 7-hour delivery intervals:
- - from 10:00 to 16:00
- - from 15:00 to 22:00
If you want to reduce the waiting period, you can choose one of the 3-hour delivery intervals for an additional fee:
- - from 10:00 to 13:00 +350.00 ₽.
- - from 13:00 to 16:00 +300.00 ₽.
- - from 16:00 to 19:00 +300.00 ₽.
- - from 19:00 to 22:00 +350.00 ₽.
Rescheduling the date and changing the delivery time interval is possible no later than 24 hours before the previously agreed date and time.
Read more about the working conditions courier service can be found in the section
A dielectric coupling is a cut-off fitting that protects the “brains” of gas-consuming devices from destructive impact stray currents. That is, we have before us a very useful unit, the effectiveness of which has been proven by the definition itself. However, many owners of gas stoves, water heaters and boilers, as well as employees of gas services, do not know about the existence of such an insert. And in this material we will try to eliminate this gap in knowledge by talking about the benefits of dielectric fittings, their types and installation methods.
Stray current - where does it come from in the gas pipeline
Such currents appear in the ground due to an accidental breakdown of a household or industrial power line. The source of stray voltage can be either a grounding loop or an electrified Railway or tram line. Such current enters the gas pipeline due to the difference between resistivity earth and metal parts of the gas supply line. In fact, all electricity discharged into the ground does not go into the ground (it has too much resistance), but into uninsulated cables or metal structures. And since most of Main and household gas pipelines are made of metal, then the appearance of stray current in the system is only a matter of time.
The main pipe can become a source of stray voltage in a household gas pipeline. To protect the gas supply pipeline from corrosion, the line is loaded electric potential insignificant force, which suppresses the natural process of electrochemical splitting in the structural material. And if in the common insulator separating the main line from the household branch, a breakdown of the dielectric insert for gas occurs, then the useful protective potential will turn into an unwanted stray current.
In addition, stray voltage may appear in the internal gas supply line due to poor grounding of the circulation pump or other electrical appliances in contact with the heating system wiring or the home gas pipeline branch. Another reason for the appearance of such currents may be an error when installing a boiler, column or gas stove connected to the electrical network. As you can see, stray current is not a myth, but a real problem. And the metal structure that falls under its influence turns into a serious threat to the safety of all residents of the house connected to the gas pipeline.
What happens if the system does not have a shut-off fitting?
To cut off stray currents in pipelines, a special dielectric insert is used. It cuts into the area between the tap and the supply to the gas-consuming device. Or in the area between the gearbox and gas meter. What happens if there is no such insert? Believe me, nothing good. Firstly, your or your neighbor’s stove, water heater or boiler may suffer from stray current or become a source of it. As a result, there is a risk of losing their functionality due to damage to the “smart” filling, assembled on the basis of capricious chips that react even to minor voltage surges.
Secondly, a spark may occur in the pipeline - a source of fire. Moreover, cases of spontaneous combustion of the liner are not so rare. And if this fact is not discovered in time, the matter could end in a big disaster. The detonation of the gas-air mixture can destroy even an apartment building. Third, the user may receive an electric shock. If the potential of a stray charge is significant, and this happens during a thunderstorm or a power failure, then we may not be talking about an unpleasant “bite”, but about a full-fledged injury with difficult to predict consequences.
Therefore, in the set of rules SP 42-101-2003 regulating the construction of gas distribution systems, there is a special clause (6.4) stipulating the mandatory presence of a dielectric insert, used even in polyethylene pipelines. A modern industry produces several types of similar cut-offs.
Types of dielectric cut-offs - couplings and bushings
The product range of stray current cut-off devices for gas distribution systems is usually divided into two groups, which include:
- Dielectric couplings (MD) are special fittings with threaded ends, mounted between the gas pipeline and the device consuming blue fuel.
- Dielectric bushings (VD) are non-conducting bushings installed in the place of dismountable coupling of gas pipeline elements.
In turn, the range of couplings is divided into four standard sizes, based on the diameters of the threaded part: ½, ¾, 1, 1 ¼. Such a set allows you to cover all types of pipeline fittings used in gas pipelines, since diameters less than ½ inch and more than an inch and a quarter are not used in such systems. In addition, the range of couplings can be divided into design features this fitting, distinguishing three groups: MD thread/thread, MD thread/nut, MD nut/nut. After all, the thread of this fitting can be cut both outside and inside the end part.
The range of dielectric bushings is divided only on the basis of their geometric dimensions - by the diameter of the liner. In this case, we are dealing with 11 standard sizes and diameters from 8 to 27 millimeters. At the same time, both couplings and bushings have the same safety margin. Operating pressure of both types of cut-offs is 0.6 MPa (about 6 atmospheres), and the limit is 50 MPa (493 atmospheres). In both cases, a practically non-flammable polymer is used as a dielectric - polyamide, which has a colossal resistance (about 5 million Ohms).
How to install the coupling - proceed carefully
Point 6. 4 of the set of rules SP 42-101-2003 indicates that MD and VD must be installed between the gas distribution valve and the consuming appliance, therefore, when installing dielectric cut-offs, the following sequence of actions is used:
- Close the valve to metal pipe, supplying gas to the stove, boiler or column. In this case, it is better to leave the burners of the devices open so that the gas in the supply burns out.
- Holding the valve body with the first adjustable wrench, carefully twist the supply nut with the second wrench - a flexible pipeline (hose) connecting the shut-off unit to the gas inlet pipe of the boiler, stove or column. The use of a pair of keys in this case is mandatory, since the supply nut can “stick” to the fitting or branch pipe of the valve and transmit torque to it, after which gas will flow into the room, and its supply can only be shut off with a street reducer valve.
- We screw the FUM coupling (polymer seal) onto the free ends of the coupling and screw it into the gas pipeline valve by hand. Next, take the same two keys and, holding the valve body, screw in the coupling until it stops. Be careful not to overdo it at this stage, as too much force will cause the valve body to deform and cause gas to leak.
- We screw the supply nut to the device consuming gas onto the free end of the coupling, controlling our force and holding the fitting with one of the adjustable wrenches.
- Next, you need to check the tightness of the resulting connection. To do this, you need to purchase a shaving brush and, after thoroughly lathering it, treat all the joints of the valve, coupling and supply. After this, you open the valve and observe the foam at the joints. If you do not see any bubbles, the joints are sealed and your gas pipeline is ready for safe operation.
If found soap bubbles at the joints you need to close the gas supply valve and carefully tighten the coupling or supply nut. If this does not help, you will have to disassemble the entire connection and add several turns of FUM to the ends of the coupling.
Attention: the use of matches or lighters instead of soap foam when testing the tightness of joints is strictly prohibited. You may not have time to react and turn off the gas, causing a serious fire. And if there is a strong leak, you may be overwhelmed by panic - the sight of a flaming valve unbalanced even the most cold-blooded craftsmen. Therefore, the best leak tester is soap suds.
>Why do you need a dielectric coupling for gas and how to install it?
Dielectric coupling is a cut-off fitting that protects the “brains” of gas-consuming devices from the destructive effects of stray currents. That is, we have before us a very useful unit, the effectiveness of which has been proven by the definition itself. However, many owners of gas stoves, water heaters and boilers, as well as employees of gas services, do not know about the existence of such an insert. And in this material we will try to eliminate this gap in knowledge by talking about the benefits dielectric fitting, its varieties and installation methods.
Stray current - where does it come from in the gas pipeline
Such currents appear in the ground due to an accidental breakdown of a household or industrial power line. The source of stray voltage can be either a ground loop or an electrified railway or tram line. This current enters the gas pipeline due to the difference between the resistivity of the earth and the metal parts of the gas supply line. In fact, all electricity discharged into the ground does not go into the ground (it has too much resistance), but into uninsulated cables or metal structures. And since most of the main and household gas pipelines are made of metal, the appearance of stray current in the system is only a matter of time.
The main pipe can become a source of stray voltage in a household gas pipeline. To protect the gas supply pipeline from corrosion, the line is loaded with an electrical potential of insignificant strength, which suppresses the natural process of electrochemical splitting in the structural material. And if a breakdown of the dielectric insert for gas occurs in the common insulator separating the main line from the household branch, then the useful protective potential will turn into an unwanted stray current.
In addition, stray voltage may appear in the internal gas supply line due to poor grounding of the circulation pump or other electrical appliances in contact with the heating system wiring or the home gas pipeline branch. Another reason for the appearance of such currents may be an error when installing a boiler, water heater or gas stove connected to the electrical network. As you can see, stray current is not a myth, but a real problem. And the metal structure that falls under its influence turns into a serious threat to the safety of all residents of the house connected to the gas pipeline.
What happens if the system does not have a shut-off fitting?
To cut off stray currents in pipelines, use a special dielectric insert. It cuts into the area between the tap and the supply to the gas-consuming device. Or in the area between the reducer and the gas meter. What happens if there is no such insert? Believe me, nothing good.
- Firstly, your or your neighbor’s stove, water heater or boiler may suffer from stray current or become a source of it. As a result, there is a risk of losing their functionality due to damage to the “smart” filling, assembled on the basis of capricious chips that react even to minor voltage surges.
- Secondly, a spark may occur in the pipeline - a source of fire. Moreover, cases of spontaneous combustion of the liner are not so rare. And if this fact is not discovered in time, the matter could end in a big disaster. The detonation of the gas-air mixture can destroy even an apartment building.
- Third, the user may receive an electric shock. If the potential of a stray charge is significant, and this happens during a thunderstorm or a power failure, then we may not be talking about an unpleasant “bite”, but about a full-fledged injury with difficult to predict consequences.
Types of dielectric cut-offs - couplings and bushings
The product range of stray current cut-off devices for gas distribution systems is usually divided into two groups, which include:
Dielectric couplings (MD)- special fittings with threaded ends, mounted between the gas pipeline and the device consuming blue fuel.
Dielectric bushings (VD)- non-conducting liners installed in the place of dismountable coupling of gas pipeline elements.
In turn, the range of couplings is divided into four standard sizes, based on the diameters of the threaded part: ½, ¾, 1, 1 ¼. Such a set allows you to cover all types of pipeline fittings used in gas pipelines, since diameters less than ½ inch and more than an inch and a quarter are not used in such systems. In addition, the range of couplings can be divided according to the design features of this fitting into three groups: MD thread/thread, MD thread/nut, MD nut/nut. After all, the thread of this fitting can be cut both outside and inside the end part.
The range of dielectric bushings is divided only on the basis of their geometric dimensions - by the diameter of the liner. In this case, we are dealing with 11 standard sizes and diameters from 8 to 27 millimeters. At the same time, both couplings and bushings have the same safety margin. The working pressure of both types of cut-off valves is 0.6 MPa (about 6 atmospheres), and the maximum pressure is 50 MPa (493 atmospheres). In both cases, a practically non-flammable polymer is used as a dielectric - polyamide, which has a colossal resistance (about 5 million Ohms).
How to install the coupling - act carefully
Dielectric coupling must be mounted between the gas distribution valve and the consuming appliance, therefore, when installing dielectric cut-offs, the following sequence of actions is used:
- We close the valve on the metal pipe supplying gas to the stove, boiler or column. In this case, it is better to leave the burners of the devices open so that the gas in the supply burns out.
- Holding the valve body with the first adjustable wrench, carefully twist the inlet nut with the second wrench - a flexible pipeline (hose) connecting the shut-off unit to the gas inlet pipe of the boiler, stove or column. The use of a pair of keys in this case is mandatory, since the supply nut can “stick” to the fitting or branch pipe of the valve and transmit torque to it, after which gas will flow into the room, and its supply can only be shut off with a street reducer valve.
- We screw the FUM coupling (polymer seal) onto the free ends of the coupling and screw it into the gas pipeline valve by hand. Next, take the same two keys and, holding the valve body, screw in the coupling until it stops. Be careful not to overdo it at this stage, as too much force will cause the valve body to deform and cause gas to leak.
- We screw the supply nut to the device consuming gas onto the free end of the coupling, controlling our force and holding the fitting with one of the adjustable wrenches.
- Next, you need to check the tightness of the resulting connection. To do this, you need to purchase a shaving brush and, after thoroughly lathering it, treat all the joints of the valve, coupling and supply. After this, you open the valve and observe the foam at the joints. If you do not see any bubbles, the joints are sealed and your gas pipeline is ready for safe operation.
If soap bubbles are detected at the joints, you must shut off the gas supply valve and carefully tighten the coupling or supply nut. If this does not help, you will have to disassemble the entire connection and add several turns of FUM to the ends of the coupling.
Attention: the use of matches or lighters instead of soap foam when testing the tightness of joints is strictly prohibited. You may not have time to react and turn off the gas, causing a serious fire.
And if there is a strong leak, you may be overwhelmed by panic - the sight of a flaming valve unbalanced even the most cold-blooded craftsmen. Therefore, the best leak tester is soap suds.
1 area of use
1.1. Insulating inserts (hereinafter referred to as inserts) for intra-apartment gas pipelines are designed to prevent leakage currents from flowing through the gas pipeline when a neutralized electrified gas occurs on the housing gas appliance electric potential.
1.2. The inserts are designed for installation on gas pipelines transporting natural gas according to GOST 5542-87 and liquefied gas according to GOST 20448-90 and GOST R 52087-2003.
1.3. Application of the insulating insert provided for by SP 42-101-2003 ( General provisions on the design and construction of gas distribution systems made of metal and polyethylene pipes).
2.Specifications
2.1. Inserts are manufactured in accordance with TU 4859-008-96428154-2009.
2.2. The production of inserts is carried out in a mold on a thermoplastic machine using the screw extrusion method. polymer material as an electrical insulator and metal threaded pipes.
2.3. Operating pressure of the insert: 0.6 MPa.
2.4. Breaking insertion pressure. 1.2 MPa, no less.
2.5. Working temperature: from -20"C to +80"C.
2.7. Electric strength. Inserts withstand test voltage 37508 alternating current frequency 50Hz, applied to metal pipes. Electrical breakdown is not allowed. Electrical strength is ensured for 1 minute, no less. The leakage current does not exceed 5.0 mA.
2.8. Specific electrical resistance Inserts DC voltage 10008 is 5.0 MOhm, no less.
2.9. Resistance category of polymer electrical insulating material is PV-0 (according to GOST 28157-89). Electrical insulating material has a distinctive color yellow color(according to GOST 14202-69, group 4, flammable gases (including liquefied gases)) At the request of the consumer, the use of black material is allowed.
2.10. Marking. Markings are applied to the surface of the electrical insulating material, including the indication trademark, 1/DI-GAS, and nominal diameter, for example, DN20.
2.11. Nominal diameters of inserts (threaded pipes): DN15 (1/2"), DN20 (3/4").
2.12. Inner diameter passage. DN15 10.0 mm, DN20: 15.0 mm.
2.13. Connection type: cylindrical pipe thread, external/external thread.
3. Transportation and storage
3.1. Inserts can be transported various types transport, subject to protection from mechanical damage and exposure to precipitation in accordance with the rules of transportation for this type of transport.
3.2. Inserts are stored in closed and other premises with natural ventilation without artificially regulated climatic conditions, where fluctuations in temperature and air humidity are significantly less than in the open air (for example, stone, concrete, metal storage facilities with thermal insulation and other storage facilities), located in any macroscopic areas, including temperate and cold climates.
4. Installation and operating instructions
4.1. Installation of the Insert must be carried out by specialists who have been trained and have a license to connect gas equipment.
4.2. It is prohibited to dismantle/install the Insert without pre-coating gas supply valve.
4.3. The inserts do not require verification or maintenance during operation.
4.4 The insert is used in conjunction with a flexible metal connection to electrified gas appliances and is installed on the intra-apartment gas pipeline on the outlet after the tap.
5. Manufacturer's warranty
5.1. The manufacturer guarantees that the inserts comply with the requirements of TU 4859-008-96428154-2009 provided that the consumer complies with the conditions of transportation, storage, installation and operation.
5.2. Guarantee period operation - 36 months from the date of commissioning of the Insertion, but not more than 60 months from the date of manufacture, subject to compliance with the rules of storage, installation and operation.
5.3. The service life of the insert is 20 years. Does not require maintenance during operation.
5.4. The manufacturer reserves the right to make changes to the design of the Insert without notifying the consumer.