There is a misconception that the quality of the weld depends only on the performer, but this is far from the case, and any good welder understands this - electrodes for welding heating and water pipes play an important role in such work.

First of all, it should be noted that such conductive rods can be either metallic or non-metallic, that is, carbon or graphite, but in this case, we are not interested in the second type.

Let's look at what signs can be used to distinguish consumables of this type, how best to choose them, and the video in this article will demonstrate visual information on our topic.

How are they distinguished?

Electrodes made of metal can be consumable or non-consumable. The first type can be coated, with a steel, cast iron, bronze, copper or aluminum rod, but uncoated ones are currently used only in the form of wire (see photo above) when welding work is carried out in a gas protective environment.

The non-melting type includes intruded, thoriated, lanthanum, and tungsten, therefore, it is quite natural that their price is much higher.

In addition, electrodes are classified according to their purpose, that is, according to the type of material to be processed. For high-carbon steel according to GOST 9467-75, the material is marked with the letter U, for alloy and heat-resistant steels - with the letter T, but for deposition of the surface layer - with the letter T.

Tungsten – TIGWIG

In most cases, there is a coating on the rods, but it also varies and has its own marking according to GOST 9466-75.

For example:

• thin coating is marked with the letter A (international format - A);
• middle – letter C (international format – B);
• thick - letter D (international format - R);
• and especially thick - with the letter G (international format - C).

In addition to the thickness of the coating layer, it is classified according to its type:

• A – sour;
• B – basic;
• C – cellulose;
• R – rutile;
• P – mixed.

In addition, the mixed layer can be:

• AR – acid-rutile;
• RB – rutile-basic;
• RP – rutile-cellulose;
• RZh – rutile, with an admixture of iron powder.

Note. Due to the fact that welding work can be performed in different positions, electrodes here are classified into different types.
So, they can be for the lower position, vertical from bottom to top, horizontal and lower in a boat.
The instructions also include rods for any position.

By appointment. Types of materials

• Carbon and low alloy structural steels. In this case, the temporary tensile strength can be up to 60 kgf/mm or 600 MPa.
• High alloy steel types, which are endowed with special properties.
• Structural steels, where applicable arc welding. Here the temporary tensile strength will already be more than 60 kgf/mm or 600 MPa.
• Surfacing of the surface layer of metal, which has special properties.
• Cast iron.
• Non-ferrous metals. (See also article.)

More about coverage

• A – acid or sour coating. It contains oxides of iron, manganese and silicon.
• B – basic. It contains calcium fluoride and calcium carbonate. Welding work using such electrodes is carried out DC variable polarity.
• C – cellulose. It contains flour and other organic components, which are intended to create a gas protective shell during production welding work.
• R – rutile. It contains rutile as the main component, as well as other mineral and organic components. In addition to gas protection, such components can significantly reduce spatter during weld production.

Note. IN household use(heating, frames) everything is somewhat simpler, since for all cases they usually use electrodes with a main (B) coating, the diameter of which depends on the thickness of the metal.
For example, if you are interested in which electrodes to cook profile pipe, then given the thin profile wall (1.0-1.5 mm), you are better off using a rod with a cross-section of 2 mm.
Depending on the welding (transformer or inverter), you will select the consumables itself (for alternating or direct current).

Consumption rates

For heating installation, the consumption rates of electrodes when welding pipes may be different, depending on the type of seam, but we will only consider vertical connection without beveled edges, as the most commonly used.

Consumption of electrodes when welding pipes per meter of seam

Pipe dimensions in mm	Deposition weight in kg	Electrodes by groups in kg
		II	III	IV	V	VI
23´3	0,008	0,014	0,015	0,016	0,017	0,015
32´3	0,011	0,019	0,020	0,021	0,023	0,024
38´3	0,012	0,022	0,024	0,025	0,027	0,028
45´3	0,015	0,027	0,029	0,030	0,032	0,034
57´3	0,919	0,034	0,036	0,039	0,041	0,043

Consumption of electrodes when welding pipes per joint

Note. By by and large electrodes of any type are classified as one of the groups welding materials.
In addition to them, this includes filler rods, wire, shielding gases and filler fluxes.

Conclusion

As you noticed, there are quite a few brands of electrodes, but if you want to heat your home with your own hands, then you immediately need to select materials for high-alloy and non-ferrous steels, as well as cast iron.

In addition, the thickness of the walls of heating pipes is usually at least 2 mm, then a 3 mm rod is needed. In addition, you will need an electrode for all positions, with a medium coating (C) type, acid (A) or basic (B), for carbon and low-carbon steels.

The welding process is a rather complex and multi-component procedure that requires certain knowledge and skills. To perform a high-quality connection using welding, many nuances and parameters should be taken into account. In particular, great importance has the correct choice of electrodes for a particular case. After all, the welding mode, the amount of deposited material, the composition of the weld metal, and therefore the characteristics of the resulting weld will depend on this. Therefore, the strength of the connection largely depends on this choice.

Therefore, it must be done taking into account the properties of the material and parameters. After all, each type of electrode has its own characteristics, so it is suitable for performing some specific tasks. Therefore, it is worth considering each type of electrode that may be suitable for a particular application.

Selection by welding parameters

Rutile-acid type products have the advantage of removing slag in narrow joints.

• Rutile allows you to get an attractive appearance of the seam, the slag is easily removed, and re-ignition is easy. Used for tacks, upper layers and creating fillet welds.
• Electrodes with a rutile-base coating are used to obtain root welds, as well as in the construction of medium and small diameter pipelines.
• Rutile-cellulose has proven itself excellently in various positions. This is a universal option if the product has a thick coating.
• Cellulose ones are used for joining large diameter pipes with circumferential seams. They are suitable for making vertical seams from top to bottom. Therefore, such products are used for laying pipelines.

The main electrodes can be used for connection in any position. However appearance the seam turns out a little worse than in other cases. However, such products reduce the likelihood of cracks in the weld metal.

Effective for large wall thicknesses, as well as for poor weldability of the material. These electrodes are effectively used for welding strong steels.

Selection by material properties

In the weld metal, as in the main metal, almost the same toughness and strength indicators should be observed.

To ensure that the choice is correct according to DIN EN 499, there are instructions on the values ​​of tensile strength, yield strength, and toughness of the weld metal.

Let's give an example. Let's say the designation E 46 3 B 4 2 H5:

• E – electrode type – manual welding.
• 46 – yield strength 460 N/mm 2, minimum.
• 3 – at a temperature of minus 30 degrees a crack develops, the work of which is 47 J.
• B – main electrode coating.
• 4 – DC welding.
• 2 – welding in all positions, with the exception of vertical from top to bottom.
• H5 – hydrogen content in the weld metal up to 5 ml/100 g.

The same designation systems exist for stainless, heat-resistant and high-strength electrodes.

Diameter

Important when choosing an electrode for welding pipes, it is necessary to determine its diameter. The characteristics of the seam, as well as the consumption of filler material, depend on this.

It should first be noted that the nominal diameter is the size of the rod, without coating. As for the thickness of the coating, it is individual, determined by GOST 9466-75 according to the formula: D/d. D is the coated diameter and d is the rod diameter. Ratio:

• Equal to or less than 1.2 – thin coating;
• Equal to or less than 1.45 - medium coverage;
• Equal to or less than 1.80 – thick coating;
• More than 1.8 – especially thick coating.

It's interesting that foreign manufacturers adhere to similar rules, but the diameters of their products do not meet Russian standards.

Here are the main capabilities of electrodes, which differ in diameter:

• 8-12 mm - current strength is up to 450 Amperes, and the metal being welded has a thickness of over 8 mm. Their length is 35-45 cm. For all types of steel, for high-performance industrial equipment.
• 6 mm - current strength is 230-370 Amperes, and the metal being welded has a thickness of 4-15 mm. Their length is 35-45 cm. For all types of steel, for professional equipment.
• 5 mm - current strength is 150-280 Amperes, and the metal being welded has a thickness of 4-15 mm. Their length is 35-45 cm. For all types of steel, for powerful equipment.
• 4 mm - current strength is 100-220 Amperes, and the metal being welded has a thickness of 2-10 mm. Their length is 35-45 cm. For all types of steel.
• 3 mm - current strength is 70-140 Amperes, and the metal being welded has a thickness of 2-5 mm. Their length is 30-45 cm. For alloy and low-carbon steel.
• 2.5 mm - current strength is 70-100 Amperes, and the metal being welded has a thickness of 1-3 mm. Their length is 25-35 cm. For alloy and low-carbon steel.
• 2 mm - current strength is 50-70 Amperes, and the metal being welded has a thickness of 1-2 mm. Their length is 25-30 cm. For alloy and low-carbon steel.
• 1.6 mm – current strength is 25-50 Amperes, and the metal being welded has a thickness of 1-2 mm. Their length is 20-25 cm. For alloy and low-carbon steel.
• 1 mm - current strength is 20-25 Amperes, and the metal being welded has a thickness of 1-1.5 mm.

It should be noted that each brand of electrodes may have its own current strength, so the specified parameters are approximate. The consumption will also differ.

Right choice the electrode is the key to a high-quality and durable seam, and therefore the entire structure. Therefore, this choice should be approached especially carefully.

Regardless of where you live, in your house or in an apartment, you have probably had to deal with the need to weld metal pipes for heating or for plumbing.

When welding such pipes, you probably had to try a lot, because these were critical welds. In order for the welding to be of high quality, you probably used special electrodes for welding pipes.

With pipes that will subsequently be subjected to high blood pressure things are different, because with such welding, the seams must be as strong as possible, that is, capable of withstanding heavy loads. However, in order for the welding seam to be of high quality and durable, your skill alone is not enough.

It takes more than just experience. Yes, you need suitable electrodes, which, thanks to their special structure, will be able to make the welding seam you need. One of the most popular electrodes used in the construction of gas pipelines, oil pipelines and other critical systems , are electrodes from ESAB with the same name "ESAB".

ESAB electrodes are among the most popular electrodes which are used in welding different types steel, as well as when welding pipe structures. For welding pipelines ESAB electrodes OK 53.70 and OK 74.70.

They are designed specifically for thorough welding of the root of the seam, and if the root of the seam is welded perfectly, this means that further welding will be successful. They are also used as a filling material, and also for welding the facing layer, which will be visible to people. ESAB's wide range of electrodes allows you to choose best electrodes for welding critical pipelines.

In addition to this type of electrode, MP-3 electrodes are sometimes used for welding pipelines under pressure. They are similar in many ways to OK electrodes from ESAB, but have several disadvantages. For example, they have more metal spatter than electrodes OK 53.70 or OK 74.70.

If a novice welder decides to weld pipelines with ESAB or MP-3 electrodes, then he is on the right track, because the high quality of both brands of electrodes will help him quickly learn how to weld, because with their help welding will occur quickly and comfortably.

However, it is best to follow the advice of professional welders and use electrodes from ESAB. Of course, no one is saying that MP-3 electrodes are bad, but nevertheless, many professionals choose ESAB. Most likely, almost all welders know that the experience of professionals is invaluable, so you need to listen to it.

No matter what, buy electrodes and use them for their intended purpose, just remember that high-quality pipeline welding under pressure is only possible with these electrodes.

There is an erroneous conclusion that the level of quality of the weld depends only on the performer, but this is far from the case, and any good welder understands this - electrodes for welding heating and water pipes play a significant role in such work.

First of all, we want to emphasize that such conductive rods can be either iron or non-iron, in other words, carbon or graphite, but in this case, the second type does not interest us.

Let's look at what indicators it is possible to distinguish between consumables in order to see how best to select them, and the video in this article will demonstrate visual information on our topic.

How are they distinguished?

Electrodes made of metal can be melting or non-melting. The first type is possibly coated, with a steel, cast iron, copper, bronze or aluminum rod, but uncoated ones are currently used only in the form of wire (see photo above), while welding work is carried out in a gas protective environment.

The non-melting type includes intruded, thoriated, lanthanum, and tungsten, based on this, it is completely natural that their price is much higher.

In addition, electrodes are classified according to their purpose, in other words, according to the type of material to be processed. For high-carbon steel according to GOST 9467-75, the material is marked with the letter U, for alloy and heat-resistant steels - with the letter T, but for deposition of the surface layer - with the letter T.

As a rule, there is a coating on the rods, but it also varies and has its own marking in accordance with GOST 9466-75.

So, for example:

• narrow coverage is marked with the letter A (international format - A);
• middle - letter C (international format - B);
• thick - letter D (international format - R);
• and very thick - the letter G (international format - C).

In addition to the thickness of the coating layer, it is classified according to its type:

• A - sour;
• B - main thing;
• C - cellulose;
• R - rutile;
• P - mixed.

In addition, a mixed layer is possible:

• AR - acid-rutile;
• RB - rutile-basic;
• RP - rutile-cellulose;
• RJ - rutile, with an admixture of metal powder.

Note. Due to the fact that welding work can be carried out in different positions, electrodes here are classified into different kinds. So, they can be for the lower position, vertical from bottom to top, horizontal and bottom in a boat. In addition, the instructions also include rods for any position.

By appointment. Types of materials

• Carbon and low alloy structural steels. In this case, the temporary tensile strength can be up to 60 kgf/mm or 600 MPa.
• High alloy steel types, which are endowed with special properties.
• Structural steels where arc welding is used. Here the temporary tensile strength will already be more than 60 kgf/mm or 600 MPa.
• Surfacing of the surface layer of metal, which has special properties.
• Cast iron.
• Non-ferrous metals. (See also the article Sewerage in a cottage: highlights.)

More about coverage

• A - acid or sour coating. It contains oxides of iron, manganese and silicon.
• B is the main thing. It contains calcium fluoride and calcium carbonate. Welding work using such electrodes is carried out with direct current of alternating polarity.
• C - cellulose. It contains flour and other organic components, which are intended for a gas protective shell during welding work.
• R - rutile. It contains rutile as the main component, and other mineral and organic components. In addition to gas protection, such components can significantly reduce spattering during weld production.

Note. In domestic applications (heating, frames), everything is simpler, since in most cases electrodes with a basic (B) coating are used there, the diameter of which depends on the thickness of the metal. For example, if you are interested in which electrodes to weld a profile pipe, then given the narrow profile wall (1.0-1.5 mm), it is better for you to use a rod with a cross-section of 2 mm. Depending on the type of welding (transformer or inverter), you will begin to select the consumables itself (for alternating or direct current).

Consumption rates

For heating installation, the consumption rates of electrodes when welding pipes can be different, depending on the joining of the welded heating pipes and type of seam, but we will consider only a vertical connection without beveled edges, as is most often used.

Consumption of electrodes when welding pipes per meter of seam

Pipe dimensions in mm	Deposition weight in kg	Electrodes by groups in kg
II	III	IV	V	VI
23?3	0,008	0,014	0,015	0,016	0,017	0,015
32?3	0,011	0,019	0,020	0,021	0,023	0,024
38?3	0,012	0,022	0,024	0,025	0,027	0,028
45?3	0,015	0,027	0,029	0,030	0,032	0,034
57?3	0,919	0,034	0,036	0,039	0,041	0,043

Consumption of electrodes when welding pipes per joint

Note. By and large, electrodes of any type are classified as one of the groups of welding materials. In addition to these, this includes filler rods, wire, shielding gases and filler fluxes.

Conclusion

As you have seen, there are enough brands of electrodes a large number of, but if you want to heat the house with your own hands, then you immediately need to discard the materials for high-alloy and non-ferrous steels, and cast iron.

In addition, the thickness of the walls of heating pipes, in most cases, is not less than 2 mm, then a 3 mm rod is needed. In addition, an electrode for all positions is suitable for you, with a medium-hard coating (C) type, acidic (A) or basic (B), for carbon and low-carbon steels.

There is an opinion that welding pipes is quite simple technological operation, which even a beginner can handle.

Indeed, it would seem that there is nothing complicated here. The parts are quite large, the connecting surfaces are well adjusted to each other and processed, the material is of high quality. At first glance, there is everything necessary to form an aesthetic and durable seam!

In practice, however, it turns out completely differently. This process is quite difficult, especially if we're talking about on the formation of a full-fledged pipeline operating under pressure. The best specialists are attracted to work with its segments.

Why is this happening? How to perform high-quality welding without significant experience? What tips and tricks should you follow?

The most common and popular technique is electric arc welding.

Yes, it has alternatives in the form of gas welding, but its undeniable advantages lie in simplicity, a minimal set of equipment and a result that meets the most stringent standards.

Even when designing main pipelines, this method is used. To achieve High Quality, it is necessary to treat the work with full responsibility.

Selecting Electrodes

Connecting Segments steel pipelines must be carried out using high-quality consumables, otherwise it is unlikely that a good result will be achieved.

For example, when it comes to choosing electrodes, the following models are considered the best:

• , ANO-24 and. They operate on alternating currents. Work is allowed even with wet coating. The cost of the products is low, which explains their demand in everyday life; they are ideal for connecting structural elements gates, greenhouses and other structures of small mass that do not experience high loads. Work with pipelines in which the medium is transported under significant pressure is not permitted.
• . The quality of the cores deserves flattering reviews even from professional welders, but they have a disadvantage - work cannot be carried out at high speed. It is necessary to constantly monitor the stability of the arc; the weld is deposited gradually, so the worker must have some experience in interacting with classic ANO and MR electrodes.
• Excellent for metal pipes. This is a Japanese development. It is she who is given preference when implementing major projects. They form an even and stable arc, the resulting seam combines strength and aesthetics. The downside is the rather high cost, but they are suitable for both specialists and beginners.

Watch a video on the topic of which electrodes to use for welding pipes:

Basic methods

The connection can be made in one of the following ways:

1. Butt joint, when the pipes to be connected are placed opposite each other. The most common option, characterized by relative ease of implementation. However, it is also characterized by certain difficulties. The first point is that it is better to work from below. The second point is that the metal must be thoroughly welded so that the depth of welding corresponds to the thickness of the wall.
2. Overlapping. This method is focused on connecting elements that initially differ in diameter, or segments, one of which is flared, that is, its diameter is intentionally increased by mechanical action.
3. The T-joint is made at a 90-degree angle.
4. A corner connection assumes that the angle between the connected segments is less than 90 degrees.

Before electric welding pipes, it is worth remembering a number of tips, following which will simplify the process and also improve the quality of the final result:

• If the connection is made using the butt or tee method, then electrodes whose diameter varies from 2 to 3 millimeters perform best.
• The recommended amperage is from 80 to 100 amperes, with the exception of overlap welding, when it is recommended to increase it to 120 amperes.
• When filling a welding seam, you need to ensure that the rise of the metal above the plane of the element reaches 2-3 millimeters.
• If the cross-section of the pipe is not the usual ovals or circles, but profiles, that is, rectangles and squares, then a point method of connecting it is used.

Its essence is that you first need to cook small area on one of the sides. Next - a similar section on the opposite side, then - on the remaining two planes. Only after this the pipe is finally welded.

This approach makes it possible to eliminate the possibility of warping of the product when the temperature rises; its geometry remains stable.

Preparatory operations

The final quality of the joint depends not only on the professionalism of the welder and the use of the “correct” electrodes, but also on how well the preliminary preparation is done.

It consists of the following operations:

• Checking the compliance of the geometry of the connected elements with the selected technology. It must be remembered that the wall thickness must be identical, otherwise it will not be possible to fully weld a thick-walled pipe, and in the case of working with a thin-walled product, on the contrary, the risk of burn-through increases.
• The presence of defects on the welded products, be it cracks, creases or deformations, is not allowed. During the process of thermal expansion, they can turn into areas complete destruction designs.
• Geometric deviations of the cut are not allowed. Its angle must be 90 degrees, otherwise the welding seam will not be strong enough and problems will arise with its formation, which will pose a threat of destruction of the entire structure.
• The edges of the connected pipes must be cleaned until a shiny metal surface appears, for which coarse sandpaper or a special brush is used. The minimum length of the area to be cleaned is a centimeter from the edge.
• Grease and other contaminants, traces of paint and corrosion are removed. Most effective remedy removal - chemical solvent.

This video shows how to prepare the edges of a pipe for clearance using a grinder:

Process Features

Pipe welding technology involves following following rules:

• The seam must be continuous, that is, end at the point of its beginning. Tearing of the electrode from the surface is not allowed. It is impossible to follow the rule if the pipe diameter is too large. In such a situation, multilayer welding is used. The number of layers must be correlated with the thickness of the walls.

2 layers correspond to a thickness of less than 6 millimeters, 3 - from 6 to 12, 4 - more than 12. Before applying subsequent layers, you need to make sure that the first one has cooled completely.

• Before welding two pipes, they need to be fixed. The tack will simplify the work, eliminate transverse and longitudinal movements, and allow you to form an even and strong seam without unnecessary effort.
• When the pipe wall thickness is more than 4 millimeters, it is possible to form a root seam, the main feature of which is to fill the area between adjacent edges to the full depth. An alternative to a root seam is a roller analogue, which is identified by a 3 mm bead on top of the seam.
• Checking the quality of the seam. It is tapped with a hammer, which allows you to remove slag inclusions. After this, a visual inspection is carried out; cracks, areas with insufficient penetration, chips, gouges, and burns are not allowed.

If a liquid or other medium under pressure will be transported through pipes, a test run is carried out to determine the tightness.

Useful video

Watch the video where an experienced welder shows how to easily and quickly weld pipes for beginners:

Video for beginner welders, welding pipes with a crescent:

Conclusion

So, welding pipes is a responsible task, but with the proper approach and careful attention, even beginners can cope with it. The main thing is to do everything according to the instructions, not to deviate from technology, to remember all the little things.