Pressure of gas and oxygen when cutting metal. The cutting torch is oxygen-propane. Torch preparation

When it becomes necessary to work with thick-layer metal, a gas cutter is used. It cuts a metal sheet with a hot flame jet. It is formed by mixing two gases - propane and oxygen.

It is impossible to cut high-carbon metals, copper and its alloys, aluminum with an oxygen-propane torch. The range of materials that can be affected is limited to low-carbon steel grades from 08 to 20G according to GOST (1050-60) and medium-carbon steels from 30 to 50G2 (GOST 1050-60).

The propane cutter cuts metal having a thickness of no more than 300 mm.

All parts of gas equipment are standard and can be replaced in the event of a breakdown.

Preparation for work

Before starting work, you must make sure that there are no traces of oil and other flammable substances on clothing, floor, surrounding surfaces. Next, you should inspect the gas equipment for completeness and serviceability. The following steps will help you bring the equipment into ready mode:

Beginning of work

Oxygen consumption when cutting metal is 10 times higher than propane consumption.

Close all cutter valves and set the working atmospheres on the gearboxes: on oxygen - 5, on gas - 0.5.
Open the propane tank a quarter and set it on fire.
Place the torch nozzle at an angle against a metal surface and slowly open the oxygen control.
Proceed to the process of adjusting the flame: turn on oxygen and gas alternately until the flame turns blue and has a crown.
Choose the strength of the flame based on the thickness of the metal.

cutting process

Start cutting metal from the point from which the cut should go.
Heat this point to the ignition temperature of the metal (1000-1300 C). When the metal ignites (the surface will look wet), open the cutting oxygen valve and let out a narrow stream.
Gently guide the oxygen cutter along the cut line, at an angle of 84-85° in the opposite direction from the cut. If the thickness of the metal is more than 95mm, make a deviation of 7-10°.
After the cut line has reached 15-20 mm, change the angle of inclination to 20-30°.

With the correct choice of the speed of movement of the cutting torch, a stream of sparks and slag flies straight down from the cut, while the edges are clean, there are no smudges and deposits.

If your oxygen hose breaks while doing the job, don't panic. Shut off the propane supply and then both cylinders. The flame that disappeared during the adjustment process must be re-ignited by first closing the cutter valves.

Cutting and Welding Safety

The developed clear safety rules made it possible to make the process controlled, the life and health of the carvers and those around them became out of danger:

Use of a special mask with light filters, a respirator and a protective suit.
Admission to work for persons who have reached the age of 18 and have completed a special course in gas business, who have a certificate with a mark on this type of work.
Washing for density of all connections of equipment, pipelines and fittings to prevent gas leakage.
Use of special carts and stretchers to move individual cylinders. Lack of impact of cylinders against each other during transportation.
It is not allowed to get on the oxygen reducer, valve or hose of liquefied gas, fats, oils.
It is forbidden to open the reducer and the valve of the oxygen cylinder with greasy hands.
Before starting work, it is necessary to release the mixture of gas and air formed in the hose through the torch. Thus, we prevent the occurrence of a reverse blow to the hose and reducer.
Heating of metal only with liquefied gas without oxygen is strictly prohibited.

Today, gas cutting is the most popular method, due to the lack of strict requirements for the place of work and the ease of operation. In this article, you will learn about the features of the technology, the advantages and disadvantages of this method, the principle of operation of the equipment and its types.

Gas cutting of metal is a technology that is widely used today, since it involves the simplicity of the operation, does not require additional energy sources and sophisticated equipment. It is these methods that are used by specialists in repair, construction and agricultural work. Almost all gas cutting devices are mobile, easy to transport and use elsewhere.

The essence of the oxygen cutting process is as follows. The heater heats the metal to an average temperature of 1100 degrees C. Then an oxygen jet is supplied to the working area. The stream, in contact with the heated metal, ignites. The burning jet easily cuts the metal sheet, provided that the gas supply is constant and stable.

The combustion temperature of the metal must be less than the melting point. Otherwise, melted but not burnt masses are difficult to remove from the working area.

Thus, the cutting operation is carried out by burning the material in the gas jet. The main module of the gas cutting tool is the cutter. It provides accurate dosage mixing of gases or vapors of liquid fuel with oxygen masses into a gas-air mixture. Also, the cutter provides ignition of the resulting mixture, and a separate supply of oxygen to the workplace.

Gas cutting refers to thermal methods of metal processing. Its advantages are that it is possible to work with material of any thickness, and with high productivity. The daily output of a welder can be measured in tons. Experts note the advantages of this technology in that it is completely autonomous and does not depend on the presence / absence of power sources. Since the welder often has to work in the field or does not have the opportunity to connect to a power source at a particular facility.

Manual oxy-fuel metal cutting is available to work on a wide range of materials except brass, stainless steel, copper and aluminium.

Types of metal cutting with gas

Gas cutting of various metals is classified into several methods, depending on the gases used and some other features. Each of the methods is optimal for performing certain tasks. For example, if it is possible to connect to the network, then you can use oxy-electric arc cutting, or when working with low-carbon steels, it is better to use a gas-air mixture with propane. The following methods are most in demand in practice:

Propane cutting. Cutting metal with propane and oxygen is one of the most popular ways of working, but it has some limitations. The operation is feasible for titanium alloys, low carbon and low alloy steels. If the content of carbon or an alloying component in the material exceeds 1%, it is necessary to look for other methods of oxygen efficient metal cutting. This method involves the use of other gases: methane, acetylene, propane and some others.
Air arc cutting. Oxy-electric arc cutting is a very effective method. The metal is melted using an electric arc, and the removal of residues is performed by an air jet. Oxy-electric arc cutting involves the supply of gas directly along the electrode. The disadvantage of this method are shallow cuts. But their width when performing the work of oxygen-electric arc welding can be any.
Oxy-flux cutting. A feature of oxygen flux metal cutting is the supply of an additional component to the working area. It is a flux in powder form. This component provides greater ductility of the material during oxy-flux metal cutting. The method is used to cut materials that form hard-melting oxides. Using the method of oxygen flux metal cutting allows you to create an additional thermal effect. So the cutting jet performs the operation efficiently. Oxy-flux metal cutting is applicable to cast iron, alloy steels, aluminum, copper and copper alloys, slagged metals and reinforced concrete.
Spear cutting. Oxy-fuel metal cutting is used for cutting large steel masses, technological production waste and emergency scrap. Its peculiarity is that the speed of the operation is significantly increased. in this case it is to use a high-energy jet, which reduces the consumption of steel lances. High speed is provided due to the complete and faster combustion of the metal.

Gas consumption when cutting metal

Gas consumption to cutting volumes depends primarily on the chosen method of the operation. For example, efficient air arc metal cutting requires more gas than oxy-fuel metal cutting. Also, the consumption depends on the following parameters:

the experience of the welder, the beginner will spend more volume per meter than the master;
integrity and technological parameters of the equipment used;
brand of metal with which to work, and its thickness;
width and depth of the cut.

Below is a table if propane is used to cut metal:

Advantages and disadvantages of technology

Metal cutting with oxygen is characterized by the following advantages:

the possibility of cutting sheets and products of considerable thickness;
cutting can be performed of any degree of complexity;
the possibility of surface treatment of the material;
the optimal ratio of the cost of work and its quality;
fast enough and versatile.

Among the shortcomings should be noted:

if a specialist has little work experience, he should not undertake precise operations, since skills and knowledge are required to perform them;

the method is not safe, since an explosion of the gas-air mixture is possible;
a significant area is exposed to thermal effects;
low cutting accuracy.

Deformation of the material when cutting with gas

Since cutting metal with gas involves a thermal effect on the material, deformation is a natural consequence of the operation. Uneven heating and cooling can measure the shape of the workpiece. But there are several ways to fix this defect:

the use of tempering or firing;
straightening sheet steel on rollers, after which the material becomes more stable;
to avoid warping, you can fix the product before the operation;
perform the operation at the maximum allowable speed and others.

Kickback when cutting with gas

When working with a cutting torch, there is a possibility of kickback. In this case, the gas flow begins to burn in the opposite direction, and the process rate is higher than the gas outflow rate. This effect can disable equipment, explosion of cylinders or a gearbox. There are also risks of causing significant damage to the health of the welder and other people in the vicinity. An effective solution to these dangers is the installation of a valve.

You can see some more features in the video:

Autogenous metal cutting

The most common method for cutting metal today is autogenous, it is also called gas or oxygen. Its essence boils down to the fact that under the influence of a gas flame, the metal heats up and begins to melt, and under the influence of a jet of oxygen, it burns, making a narrow groove.

Acetylene, propane-butane, natural, coke oven gas are used as a heater.

Metal cutting can be classified depending on the desired end result:

superficial;
separating;
spear cutting.

Surface gas cutting is used in cases where it is necessary to remove metal layers in order to form splines, grooves and other structural elements.

The separating view provides for a through cut to obtain the required number of metal elements, parts. Piercing metal to produce deep or through holes is called spear cutting.

Technological process

Regardless of the types of cutting, the technology for performing this process will be the same. Gas combustion provides a temperature of 1000 to 1300 o C, it is enough to melt strong steel. During this, a strong jet of oxygen is supplied, which reacts with the molten metal molecules, oxidizing them.

The result is a cut. Oxygen is supplied under high pressure. Often it reaches 12 atmospheres, such a jet, even without fire, can cut the skin.

The structure of the cutting device is designed as follows:

gas-burner;
two balloons;
mixer;
pressure regulator;
hoses.

A gas burner consists of a head with several nozzles, three is usually sufficient. A combustible substance is supplied through two side ones, and oxygen is supplied through the third, which is located in the middle. Cylinders are intended directly for gas and oxygen, depending on the volume of the intended work, cylinders of the appropriate capacity are selected.

To ensure one hour of continuous operation, an average of 0.7 m 3 of acetylene (1 m 3 of propane) and 10 m 3 of oxygen will be consumed. In general, the required amount of feedstock will depend on the density of the metal and the required temperature to heat it. It is possible to reduce propane consumption due to special nozzle attachments that fix the gas supply in a certain direction, the closer the supply is to the oxygen jet, the higher the fuel consumption.

Hoses are needed to supply oxygen and combustible substances from cylinders to the mixer, they are also called hoses. The material from which the hoses are made is two-layer rubber, between the layers is a frame made of cotton thread. Diameter - up to 12 mm, the possibility of operation at an air temperature not lower than -35 ° C.

The pressure regulator is necessary to provide different modes and cutting speeds. By supplying a smaller amount of fuel, it is possible to provide a low temperature, which is necessary for thin steel or metal of low strength, as well as reduce the consumption of raw materials.

Another important function of the reducer is to maintain a uniform pressure level. If the gas supply is interrupted during the cutting process, the metal will quickly cool and further processing will become impossible.

Metal cutting with propane and oxygen

Necessary equipment

Cutter P101

The very first cutter was the P1-01 device, it was designed back in the USSR, then more modernized models appeared - P2 and P3. The devices differ in the size of the nozzles and the power of the gearbox. More modern manual installations:

Change;
Quicky;
Orbit;
Secateurs.

They differ in a set of additional functions and performance.

Quicky-E can carry out figured cutting, according to the given drawings, the speed of work reaches 1000 mm per minute, the maximum allowable metal thickness is up to 100 mm. The device has a set of removable nozzles to ensure the processing of metal sheets or pipes of various thicknesses.

This apparatus can operate using various types of combustible gas, in contrast to the prototype R1-01, which operates only on acetylene.

The Secator manual cutter has more improved characteristics in comparison with analogues.

With it, you can process metal up to 300 mm thick, this is provided by additional nozzles included in the kit, they are removable and can be purchased additionally as they wear out. Secator can perform the following types of cutting:

curly;
straight;
ring;
under the bevel.

The speed can be adjusted from 100 to 1200 mm per minute, and with the help of a built-in freewheel, the machine moves smoothly over the sheet of metal. The air-cooled gearbox ensures cleaner operation and reduces fuel consumption.

The above models are manual, that is, they are compact, controlled by the hands of the master. But for large volumes of processed metal, work with such

installations are inconvenient and inefficient. For industrial production, stationary cutting machines are used - this is, in fact, the same technology.

They are a machine with a tabletop in which a cutting mechanism is built. It is powered by an electric

compressor, which requires an electrical network with at least 380 V and three-phase sockets. The technology of operation of models of stationary cutting installations is nothing, but different from manual ones. The difference is only in productivity, maximum heating temperature, and the ability to process metal with a thickness of more than 300 mm.

Conditions for cutting metal with gas

Gas cutting of metal will be effective only when the ignition temperature of the metal is lower than the melting point. Such proportions are observed in low-carbon alloys, they melt at 1500 o C, and the ignition process occurs at 1300 o C.

For the high-quality operation of the installation, it is necessary to ensure a constant gas supply, since oxygen needs a constant amount of heat, which is maintained mainly (by 70%) due to the combustion of the metal and only 30% is provided by the gas flame. If it is stopped, the metal will stop producing heat and oxygen will not be able to perform the functions assigned to it.

Cutter work, metal cutting training

The maximum temperature of handheld gas torches reaches 1300 ° C, this is a sufficient value for processing most types of metal, however, there are those that begin to melt at especially high temperatures, for example, aluminum oxide - 2050 ° C (this is almost three times higher than the temperature melting of pure aluminum), steel with a chromium content - 2000 o C, nickel - 1985 o C.

If the metal is not sufficiently heated and the melting process is not started, oxygen will not be able to displace refractory oxides. The reverse of this situation, when the metal has a low melting point, under the influence of a burning gas, it can simply melt, so this cutting method cannot be used for cast iron.

Safety

It is better to entrust metal cutting with a gas installation to an experienced specialist, since if handled carelessly, the consequences can be quite sad.

Safety precautions require the following conditions:

good ventilation in the room where the work will be carried out;
at a distance of 5 meters there should not be cylinders with gas and other combustible substances;
work must be carried out in a protective mask or special glasses, as well as in fireproof clothing;
it is necessary to direct the flame in the opposite direction from the gas source;
hoses during the operation of the device must not be bent, stepped on, clamped with your feet;
if a break is taken, then the flame at the burner should be completely extinguished and the gas valves of the cylinders should be tightened.

Compliance with these simple conditions will ensure safe and efficient metal cutting work with a gas machine.

Video: Cutter operation, metal cutting training

Gas cutting seems to be a simpler process than gas welding, and therefore even a person who does not have special skills can handle it. For this reason, almost any of us can master the work with a cutting torch. The main thing here is to understand the essence of gas cutting technology. In modern conditions, propane cutters are increasingly used. Working with them requires the use of propane and oxygen at the same time, since the combination of such substances provides the maximum combustion temperature.

Advantages and disadvantages

Propane metal cutting has a number of advantages, among which are the following:

Gas cutting is in demand in a situation where it becomes necessary to cut metal of considerable thickness or create products according to templates that provide for the manufacture of a curved cut that cannot be performed using a grinder. Also, you can’t do without a gas cutter even when the task is to cut a disk out of thick metal or make a blind hole of 20-50 mm.
The cutting torch is very convenient tool in work and differs in small weight. All home craftsmen who have had experience with gasoline models are aware of the inconvenience associated with heavy weight, size and noise. In addition to the fact that vibration creates significant inconvenience, the operator is forced to provide serious pressure during operation. Gas models, on the other hand, seem to be a more attractive alternative due to the absence of all the above-mentioned disadvantages.
The use of metal cutting with gas allows you to speed up the work by 2 times, which cannot be done using a machine equipped with a gasoline engine.
Among most gases, including gasoline, propane stands out at a lower price. For this reason, it is better suited for a significant amount of work, for example, if the task is to cut steel for scrap metal.
When using propane cutting, it is possible to create a narrower cut edge than when working with acetylene torches. At the same time, the method under consideration allows you to create a cleaner cut than that which can be performed using gasoline burners or a grinder.

Among the disadvantages that propane cutters have, only one should be singled out: they can only be used for a limited range of types of metals. They are suitable for cutting only low and medium carbon steels, but also ductile iron.

Features of use

Such tools are not suitable for cutting high-carbon steels because they have a fairly high melting point, which is almost the same as the flame temperature. This leads to the fact that instead of ejection of scale, which looks like a column of sparks, from the reverse side of the sheet, it is mixed with molten metal along the edges of the cut. As a result, oxygen cannot reach the thickness of the metal, which is why it cannot burn through the material.

Difficulties when cutting cast iron creates the shape of the grains, as well as graphite between them. True, this does not apply to ductile iron. It is impossible to solve the problem if you have to deal with aluminum, copper and their alloys.

It is important to dwell on the following point: the category of low-carbon steels is represented by grades from 08 to 20G, medium carbon - grades from 30 to 50G2. A characteristic feature of carbon steel grades is the presence of the letter U in their name in front.

As with any other job, even before you start cutting metal with gas, you should prepare the necessary equipment:

Cylinder with propane and oxygen - 1 pc.;
High pressure hoses;
Cutter;
Mouthpiece, which must have certain dimensions.

A prerequisite is the presence of a reducer on all cylinders, with which it will be possible to adjust the gas supply. It should be remembered that the propane tank has a reverse thread, which is why it will not work to screw an additional gearbox onto it.

In general, gas equipment for cutting metal has a similar device, regardless of the manufacturer. In design three gates can be distinguished:

the first provides the flow of propane;
the second valve allows you to change the oxygen supply;
the last is the cutting oxygen valve.

Blue markings are usually used to designate oxygen valves, and red or yellow markings for propane supply valves.

Metal cutting is provided by a jet of hot flame that acts on the metal, which is created using a cutter. When it is turned on, propane and oxygen are mixed in a special mixing chamber, which leads to the appearance of a combustible mixture.

With a propane torch, you can cut metal, the thickness of which does not exceed 300 mm. The detailed installation is equipped with elements that are mostly interchangeable. For this reason, if one or another part fails, it will not be difficult for the operator to carry out repairs directly at the workplace.

With special care should be approached to the choice of the mouthpiece. The key parameter to pay attention to is the thickness of the metal. If you have to deal with an object that provides elements of different thicknesses, ranging from 6 to 300 mm, then you will have to prepare mouthpieces with internal numbers from 1 to 2, and external ones from 1 to 5.

Preparation for work

Even before starting gas cutting, it is necessary to inspect the device, make sure that the propane torch is in working order. Next you need perform the following operations:

Getting Started

First you need to move the oxygen reducer to the position corresponding to 5 atmospheres, gas - 0.5. You also need to make sure that each valve is in the closed position.

After that, you need to take a propane cutter and slightly open the propane, and then set fire to it. The torch nozzle must be positioned so that it rests on the metal, after which it is necessary to slowly open the regulating oxygen. Next, you should adjust these valves one by one, thereby ensuring the required flame supply force. During such a setting, you need to sequentially open gas, oxygen, gas, oxygen.

When choosing the strength of the flame, it is necessary to focus on the thickness of the metal. With an increase in the thickness of the sheet, it will be necessary to increase the strength of the flame, which will lead to an increase in the consumption of oxygen and propane. After setting the flame strength, you can start cutting metal. The nozzle must be held in relation to the edge of the metal so that it is 5 mm away from the object being cut, and it must be at an angle of 90 degrees. In some cases it may be necessary cut through the sheet or product in the center. In this case, the place from which the cut will go is chosen as the starting point.

The essence of the procedure is to heat the upper edge to a temperature of 1000-1300 degrees Celsius. The exact temperature is determined taking into account the metal. In practice, such work will look like when the surface seems to be “wet”. It will take no more than 10 seconds to warm up. After waiting for the metal to ignite, you need to open the cutting oxygen valve, after which a powerful narrowly directed jet will begin to flow.

Cutting features

When opening the propane torch valve, do not rush. In this case, the ignition of oxygen will occur naturally as a result of interaction with the heated metal. By doing so, you eliminate the risk of kickback flame, during which you can see the pop. It is necessary to slowly lead the oxygen jet strictly parallel to the given line. It is important not to make a mistake with the angle of inclination.

First, it is maintained at a value of 90 degrees, after which it is necessary to create a slight deviation of 5-6 degrees in the direction that is opposite to the movement of the cutter. If you have to deal with metal whose thickness is more than 95 mm, then it is allowed to increase the deviation to 70 degrees. After the cut in the metal reaches 15-20 mm, the angle of inclination begins to increase to 20-30 degrees.

The nuances of metal cutting

When cutting metal, it is important maintain the required speed. Its selection is carried out visually, for which the speed of sparks is estimated.

If the speed is optimal, then the stream of sparks will fly out at an angle of about 88-90 degrees with respect to the surface being cut. In a situation where the flow of sparks tends in a direction that is opposite to the movement of the torch, it can be concluded that the cutting speed is set too low. In some cases, the stream of sparks flies out at an angle of less than 85 degrees. This is a hint that the current cutting speed is too high.

When cutting with gas, it is important to take into account such a parameter as the thickness of the metal. If it has a value of more than 60 mm, then it is desirable to place the sheets at such an angle that the slags easily go to the side.

If you have to work with metal having a significant thickness, then a special approach must be applied here. It is unacceptable to move the cutter until the metal is cut to its full thickness. As the cut is completed, it is important to gradually reduce the advance speed and maintain the angle of the torch. more than 10-15 degrees. The cutting procedure itself should be carried out in such a way that no significant pauses occur during it. If it so happened that you had to stop at a certain area, then you do not need to return to cutting at the point where the work was interrupted. It starts over, and a new starting point is chosen.

After cutting is completed, the cutting oxygen supply must be shut off, after which the same is done with the regulating oxygen. The final action should be to turn off the propane.

Surface and shape cutting

In some situations, it may be necessary to create relief on the surface by cutting grooves into the sheet. If it is decided to use a similar cutting method, then heating the metal will provide not just one cutter flame. The molten slag will also contribute. Becoming liquid, it will spread over the entire surface, which will lead to heating of the lower layers of the metal.

The first step in the implementation of surface cutting is the heating of the selected area to the ignition temperature. After starting the supply of cutting oxygen, you will create a metal burning zone, and due to the uniform movement of the cutter, the cut line will receive a clean edge. The operation itself must be performed in such a way that the cutter is at an angle of 70-80 degrees with respect to the sheet. When cutting oxygen begins to flow, the cutter is positioned so that it forms from the surface to be treated angle of 17-45 degrees.

To create grooves of suitable sizes, it is necessary to change the cutting speed: for greater depth, the speed is increased, and for shallower, it is reduced. To create more depth, you need to increase the angle of the mouthpiece, cutting must be done at a slower pace, while the oxygen pressure will also have to be increased. The width of the groove can be influenced by the correct diameter of the cutting oxygen jet. It should be borne in mind that the difference between the depth of the groove and its width should be up to 6 times. Moreover, the latter should have an advantage. Otherwise, you may encounter such an unpleasant phenomenon as occurrence on the surface of sunsets.

Conclusion

Despite the fact that, against the background of gas welding, gas cutting has its positive aspects, this work should be approached with the same responsibility. In addition to preparing the necessary equipment, you should familiarize yourself with the main nuances of this work. And although this operation seems quite simple, if mistakes are made during gas cutting, this can lead to serious problems associated with subsequent use of the product.

R3P is designed for cutting metal using a combustible mixture (propane + oxygen). This model is in demand, it can be called the most popular among propane cutters, it is sold regularly. The cutter is produced in Izhevsk, so the quality is decent. This model is also called JET 055. But all knowledgeable gas cutters call it simply - p3p. (Length 480 mm). By the way, there is also an elongated model - by 800 mm and 1000 mm. They cost a little more. Let's consider the tool in more detail.

It is intended for oxygen cutting of steel (low-carbon and low-alloy), that is, for ordinary ferrous metal. Very often I had to see how metal is cut with this cutter right in the fields (for example, you found a heavy part from a tractor weighing about 300 kilograms in a field or forest, how to take it to a metal delivery point - of course, cut it into pieces - here is such a cutter and useful).

For cutting you will need 2 cylinders with a lawn - combustible (propane) and oxygen. You will also need a 9 mm oxygen hose, 2 reducers - propane (orange) and oxygen (blue) and the cutter itself.

It consists of a barrel (2 tubes), at the end there is a thickening - a mixing chamber, where 2 gases are mixed, forming a combustible mixture. Next comes the tip, consisting of two mouthpieces - inner and outer. There are 2 fittings for connecting propane and oxygen. By the way, when you screw the adapter for connecting the hose to the propane fitting, then there is a left-hand thread, so screw it in the opposite direction. The oxygen fitting has a normal, right-hand thread.

The cutter has 3 valves - combustible gas, oxygen and the actual cutting valve - oxygen dir.

Equipment:
The cutter itself
2 nipples (hose adapter)
2 nuts (left for propane, right for oxygen)
2 additional mouthpieces No. 1 and No. 3, number 2 is already installed.

Mouthpiece numbers - for adjusting the strength and thickness of the flame, number 3 has a thick hole, so the flame is stronger and thicker - for cutting something thick and large. If it is necessary to make a thin cut, then a mouthpiece number 2 or even 1 is placed. Accordingly, a mouthpiece with a thicker hole “burns” more gas, the consumption of a combustible mixture is higher.

Beginning of work:

Propane is connected to the bottom fitting, oxygen - to the top. Before starting work, make sure that all connections are securely fastened and that there is no gas leakage. All fasteners must be on clamps, sealed. Next, set the gas pressure according to the table in the instructions.

How to cut metal with an oxy-propane torch?

Then we open the oxygen valve a quarter turn, then the propane valve 1 turn. Adjust the flame with the cutter valves, then open the cutting gas - oxygen valve. You can work. Turn off the gas in the following order - first combustible gas, then oxygen.

Cutting metal with a propane torch R3P will help out in conditions of unavailability of electricity, when it is not possible to work as a grinder. By the way, here is a small table showing which inner mouthpiece number is suitable for what thickness of the metal being cut:

No. 1 5-25 mm
№2 up to 50 mm
№3 up to 100 mm
No. 4 50-100 mm
No. 5 100-200 mm
No. 6 200-300 mm

If you install the inner mouthpiece No. 5 and No. 6, then they already need another outer mouthpiece - No. 2. The fifth and sixth numbers are designed for cutting very thick metal, so they are elongated and have a large hole diameter.

The approximate price of R3P is 1400 rubles.
R3PS(800 mm) - 1950 rubles
R3PS(1000 mm) - 2050 rubles

Laser cutter for metal - how does it work, is it possible to make it yourself?

Cutting metal with a torch

Using an insert cutter turns a gas burner into a tool that cuts metal along straight and curved contours, makes holes of large and small diameters, cuts pipes and metal rods. The insert cutter is the most convenient device for beveling the edges of products that need to be butt-jointed. Prior to cutting, the metal is heated by an annular flame created by holes in a special mouthpiece located in a circle. After heating the metal with the help of a lever, the oxygen supply is turned on through the central hole in the mouthpiece, which burns out the metal as the cutter moves along the cut line. Both during heating and cutting, the edge of the core of the flame should be approximately 3 mm above the metal.

To improve the accuracy of cutting, the cut line should be applied with a special chalk that does not collapse when heated. The marking of the cut line can also be done with a center punch, placing the marks left by it at a distance of about 6 mm from each other. A corner or a special jig should be used as a guide for moving the insert cutter along the cut line.

As with welding, different insert torches are used to cut different thicknesses of metal. There is a table that allows you to select the torch recommended for the job, as well as the appropriate oxygen and acetylene pressures (other than those recommended for welding).

Rice. 123. Insert cutter device: 1 - mouthpiece; 2 - insert cutter; 3 - oxygen supply lever; 4 - oxygen supply valve; 5 - cutter handle; 6 - holes for metal heating; 7 - hole for cutting metal

Rice.

124. Flame adjustment: 1 - oxygen supply valve; 2 - valve for supplying oxygen to the burner; 3 - valve for supplying acetylene to the burner; 4 - normal cutting flame

Insert cutter device(Fig. 123). A plug-in cutter is screwed to the barrels of the welding torch, which supplies a mixture of oxygen and acetylene through one tube into small holes in the mouthpiece arranged in a circle. This mixture is used to preheat the metal before cutting. For cutting metal, a separate tube is provided, which opens and closes with a special lever and supplies oxygen from a cylinder into a large central hole in the mouthpiece. The oxygen supply valve is used to control the supply of oxygen to the preheat port. Oxygen is supplied to the central opening under pressure, which is maintained in the supply hose.

Flame adjustment(Fig. 124). Prepare the setup in the same way as for welding and attach the torch insert to the welding torch shafts. Set the operating pressure of oxygen and acetylene to the recommended values for the given mouthpiece size. To ignite the torch, open the oxygen supply valve fully and the acetylene supply valve approximately halfway and ignite the gas by bringing the igniter to the mouthpiece. Set the flame to normal by turning the oxygen supply valve on the torch insert. Press the oxygen supply lever for a second and check the resulting flame (make it normal if necessary).

Rice. 125. Oxy-fuel cutting in a straight line: 1 - clamp; 2 - cutting line; 3 - conductor; 4 - oxygen supply lever

Using a homemade guide(Fig. 125). Mark the cut line with special chalk or a punch and place the workpiece on a table covered with metal so that the distance from it to the edge of the table is at least 100 mm. Using two clamps, secure a piece of angle so that there is a distance of about 6 mm between it and the cut line and it can be used as a guide. Pressing the side of the burner against the corner, make two or three slow passes along this line. For stability, rest your forearm on the table. Preheat the metal at the beginning of the cut to a bright red color, then fully open the oxygen supply with the lever and begin to evenly move the torch flame along the marked line, using the angle as a guide.

Rice. 126.

Cutting metal with an oxy-propane torch

Using oxyfuel cutting to bevel: 1 - conductor; 2 - cutting line

Beveling Edges with Guide Cutting(Fig. 126). Draw a cutting line on the workpiece and fix the workpiece on the table so that the distance from it to the edge of the table is approximately 100 mm. Set the corner piece so that it is in the shape of the letter L at a distance of about 6 mm from the cut line. To secure the corner in place, clamp its rear shelf with two clamps. Heat the metal along the cut line and bring it to a bright red color at the beginning of the cut line. Fully open the oxygen supply and begin to move the torch flame evenly along the marked line, pressing the side of the torch against the corner, due to which the cut is made along a plane inclined at an angle of 45 degrees.

Punching holes and cutting pipes

Rice. 127. Cutting holes of different diameters

Cutting holes of large and small diameters(Fig. 127). To cut a hole up to 15 mm in diameter, heat the cutting site by holding the edge of the flame core approximately 3 mm above the metal surface. Then use the lever to gradually turn on the oxygen supply to burn through the metal. To cut holes of a larger diameter, draw the outline of the future hole and burn a hole in the center of this outline. Bring the through cut to the edge of the outline, and then lead it further along the circumference.

Rice. 128. Pipe cutting

Pipe cutting(Fig. 128). Draw a cutting line around the pipe. Starting at the top of the tube, heat the metal by pointing the torch mouth toward the center of the tube, then press the oxygen lever and burn the hole. Holding the mouthpiece of the torch towards the center of the pipe, cut through the middle of the pipe on one side. Release the oxygen lever, raise the torch, and starting again at the top of the pipe, heat the pipe and cut through to the back. To complete the cut, turn the pipe and repeat the procedure on the other side.

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