DIY stainless steel coil. Simple ways to bend a copper tube Where to get a stainless tube

During production building structures or installation of water supply and heating systems, sometimes it becomes necessary to bend pipes. Moreover, the required bending radius can be obtained from blanks with a profile or circular cross-section. There are many ways to bend tubular elements. The choice of one method or another depends on the wall thickness, pipe cross-section, material, bending radius, and the availability of special tools. In our article we will tell you how to correctly bend a stainless steel pipe so as not to damage it. At the same time, we will list the main industrial methods bending, as well as methods that can be used at home.

All methods of bending workpieces can be divided into manual and mechanical, as well as hot and cold. Sometimes the bending process is accompanied by undesirable consequences for the tubular product, which have a significant impact on the subsequent operation of the element. The extent to which these consequences occur depends on the material from which the pipe is made, its diameter, bending radius, and the method by which the bending procedure was performed.

Attention: stainless pipe can only be bent using cold methods, that is, without heating with a torch.

TO negative consequences bending the following points can be attributed:

• Reducing the wall thickness of the workpiece located along the outer bending radius.
• The formation of creases and folds on the wall, which is located along the inner radius of the bend.
• Changing the configuration of the section (reducing the size of the lumen and its shape - ovalization).
• Change in bending radius due to the springing effect of the material.

The most common drawback of bending is a change in the cross-section configuration and wall thickness. Due to metal stresses, the outer wall at the bend becomes thinner, and the inner wall, on the contrary, thickens. Because of this, a noticeable weakening of the tubular element occurs. This phenomenon is dangerous due to the rupture of the outer wall of the pipe, since it is this wall that is exposed to greater pressure from the transported medium.

Ovalization also significantly weakens the workpiece. This phenomenon is especially dangerous when bending a pipeline intended for transporting a substance under conditions of pulsating load. If such elements are used as building structures, then ovalization will affect appearance element. That is why during the bending process they strive to minimize such phenomena.

If on inner wall folds are formed due to thickening of the material, they will entail not only a reduction in the cross-section, but will also create resistance to the moving flow. This in turn will increase the likelihood of corrosion. Besides load bearing capacity of the structural tubular element will decrease.

Protection against ovalization

The main methods of cold bending of galvanized pipes include measures that allow bending the workpiece, preserving its shape as much as possible. cross section. Typically one of two methods is used for this:

• The use of measures to preserve the shape of the section from the inside (application internal limiter).
• Using an external stop to prevent expansion of the side walls.

Important: a mandrel - a calibrating plug or fillers such as fine sifted sand or frozen water - can act as an internal limiter. Low-melting metals, rubber and resins are also used as fillers.

Rigid materials as fillers retain their shape better, so they are used more often. But thanks to the use of elastic fillers, less stretching of the outer surface of the bend occurs.

Industrial cold bending methods

Basic industrial methods cold bending:

• Winding method. This technique allows you to bend a pipe with a cross-section in the range of 1.0-4.26 cm in different planes. To maintain the shape of the section, composite or rod mandrels are used - calibrating plugs.
• With run-in. This method is suitable for bending tubular elements with a diameter of no more than 15 cm. In this case, the wall thickness should be impressive. The essence of the method: a rolling roller moves around a static bending roller of a given size. He presses the pipe and bends it.
• Rolling. This method allows you to bend the workpiece in a spiral or into a ring. On rollers, the element is moved by rollers and acquires the curvature specified by the position of the rollers.
• By drawing. The method is suitable for bending thin-walled, seamless products. For bending, a template is made from a tubular element of larger diameter. The template is then threaded through the die and secured with a clamp. Due to the rotation of the template, the workpiece is pulled through the die and bent.
• By stretching. This technique allows you to minimize the risk of metal deformation. To do this, the workpiece is fixed at the edges, stretched and bent simultaneously through the use of a bending template.
• On supports. Typically, two supports are used on which the workpiece is laid. As the supports bend, they rotate around their axis. The template is connected to the jack rod so that the force is applied in the center of the workpiece. The method is suitable for bending tubular products with a diameter of no more than 35.1 cm. The equipment allows bending to be performed directly on the construction site.
• With hydrostatic pressure inside. For this purpose in tubular element liquid is pumped. Plugs are installed at the ends. Due to the stresses that arise, the metal reaches an almost plastic state. Then a template is brought to the bending point and the workpiece is bent.
• With pushing. The method is suitable for bending elements with a diameter within three inches. The workpiece is pushed through a fixed and movable die. Due to the displacement of the matrices relative to each other, the curvature of the bend can be adjusted. Using this technique, one workpiece can be bent several times in different planes.

As for the use of mandrels, the simplest plug for pipes with a cross-section of no more than 3.2 cm can be steel rope. One end of this cable is fixed in the handle. The other end is connected to the wire to pull into the lumen. In this case, the diameter of the calibrating plug should be slightly smaller than the cross-section of the tubular product - approximately 0.1-0.5 mm.

When using calibration plugs on inner surface Undesirable scratches and nicks may occur on the workpiece. This usually happens when bending stainless steel products. To protect against such undesirable consequences, you need to choose the right material for making the cork, as well as use lubricant and thoroughly clean the surface.

Important: for lubrication you can use a soapy anti-corrosion emulsion or machine oil. Lubricate better all element by immersing it in a bath of the substance. To lubricate a bend that is far removed from the ends of the workpiece, use a mandrel with holes through which lubricant can be supplied.

Manual bending methods

To bend the workpiece at home, you can use a manual pipe bender. The most commonly used tool is a crossbow type, which bends the element by extruding it at the point of bending.

Attention: when bending at home, you should also try to avoid the undesirable consequences of this procedure.

In order to prevent changes in the cross-sectional configuration of the tubular element, means are used to counteract deformations from the inside. Typically, clean sand sifted through a fine sieve is used for these purposes. The procedure is performed in the following sequence:

1. A plug is driven into one side of the workpiece, for example, a wooden chopper.
2. Prepared sand is poured into the remaining hole.
3. This hole is also tightly closed with a plug.
4. After this, the pipe is bent around a blank of a suitable size.
5. After this, the plugs are removed and the sand is poured out.

Instead of sand, frozen water can be used as a limiter if the procedure is performed in winter. In this case, water is poured into the workpiece cavity, which is closed on one side. Then the second hole is also plugged. Bending around the blank is performed after the water freezes. After removing the plugs, the ice will melt on its own and the water can be poured out of the pipe.

Important: for bending at home, only galvanized pipes with a diameter of no more than 4 cm and a wall thickness of no more than 3 mm are suitable. Otherwise, it is better to use only professional methods.

You can also bend a galvanized pipe yourself using a spring. To do this, do the following:

1. A spring is specially made from wire with a diameter of 1-4 mm. In this case, it must fit freely inside the tubular element.
2. We tie a wire to one end of the spring and fix it on the edge of the workpiece, so that later the spring can be removed without any problems. We place the spring product itself in the place of the pipe where it is planned to bend.
3. We bend the workpiece around a steel blank or using a manual pipe bender.
4. The spring can now be removed.

This technique is ideal for bending profile pipes. Just keep in mind that the spring must have the configuration of a bendable element.

Another method is performed using a bundle of wire. Each wire is individually inserted into the workpiece so that the entire bundle tightly fills the tubular element. After bending, the wire is removed individually from the pipe cavity in the same way.

The coil is a mandatory part moonshine still, designed for condensation of alcohol vapor due to heat removal by water or air through the walls. Despite the complex definition, anyone can make a coil at home. Homemade option will work no worse than store-bought analogues. We will look at the theory and practice of manufacturing.

Coil parameters:

1. Material. The most important factor influencing the safety and taste of moonshine. The coil material must not react with alcohol or be toxic, but still have sufficient thermal conductivity to allow alcohol vapor to condense.

Taking into account the requirements, you can make a coil from copper, aluminum or stainless steel. Suitable material Glass is also an option, although it’s easier to buy a ready-made glass coil at a chemical store than to make something similar yourself.

Copper has the best thermal conductivity, but many moonshiners consider it a toxic material; in fact, this is not the case. For example, for several centuries the French have been distilling all strong alcohol in alambiks - special copper distillers, and so far no one has been poisoned. Aluminum is in second place in terms of thermal conductivity (1.6 times worse than copper), but it is relatively cheap, accessible and easy to process. Stainless steel coils are 3-4 times inferior to copper ones; moreover, the exact brand of stainless steel is not always known, and only food-grade ones are suitable for home brewing, which can withstand high temperatures and do not react with alcohol.

2. Dimensions. The longer the tube, the larger area contact of vapors with water (better cooling), but at the same time the hydraulic resistance increases (the distillation speed decreases). The correct length of the coil in a moonshine still (the tube itself before curling) is 1.5-2 meters.
The larger the cross-section (inner diameter) of the tube, the larger the contact area and the lower the resistance. I recommend using a tube with an internal diameter of 8-12 mm.

The small thickness of the coil wall increases thermal conductivity, improving condensation, but tubes that are too thin are difficult to process and operate because they are very fragile. In addition, when two media come into contact, in our case condensed alcohol and steam, the thermal conductivity drops sharply, regardless of the size and material of the wall. Optimal thickness coil tubes – 0.9-1.1 mm.

3. Orientation in space. The coil can be positioned vertically, horizontally or obliquely. In moonshine brewing, it is desirable to use a vertical connection scheme, in which the condensed distillate flows by gravity and does not create additional obstacles to the movement of steam.

Vertical coils are either ascending (steam goes from bottom to top) or descending (from top to bottom). For minimal resistance, steam should be supplied from above.

4. Cooling system. The coils are cooled with water, ice and air. The last two options are less effective and require complex structures, so we will not consider them further. Water cooling systems are open - they work at running water, and closed - the tank is immediately filled the right amount water. The design of closed systems is simpler, but they cool worse; the moonshine often comes out warm, and after a couple of hours of distillation, even hot.

In open systems, water circulation cools the coil much better, and the moonshine turns out cold. In addition, flow-through designs use a smaller volume water tank, resulting in a more compact device.

It is correct to supply water from below and remove it from above. For normal cooling, the water must move towards the moonshine, otherwise Bottom part the coil will not cool well. This scheme is called "counterflow mode".

Coil manufacturing technology

You will need a copper, aluminum, brass or stainless steel tube 1.5-2 meters long, with a cross-section of 8-12 mm and a wall thickness of 0.9-1.1 mm. I advise you to find a housing (reservoir) in advance to install the coil. The coiling diameter of the pipe depends on the size of the housing. For example, a plastic sewer pipe with a diameter of 75-80 mm is suitable. For effective cooling, the coil must occupy at least 15-20% of the tank volume.

The coil installed in the housing is called the refrigerator of the moonshine still, the drawing is shown in the photo.



Subsequence:

1. Fill the tube tightly with dry bulk material, for example, river sand or soda, so that the metal does not flatten when curling. As a last resort, you can fill the tube with water and freeze it.

2. Place wooden choppers (pegs) on the ends of the tube. Alternative option– solder or clamp tightly. It is advisable to weld a nut on one end.

3. Wind the tube around any smooth object with an even round required diameter(in the example 35 mm) with a pitch between turns of 12 mm.

4. Release the ends of the coil, pour out sand, and rinse with running water.

5. Install pipes for water supply and drainage on the cooler body.

6. Place the coil in the housing, install plugs at the top and bottom, and seal all connections with superglue or another method.

With a strong desire and in the absence of the necessary materials at hand, a system for turning mash into moonshine can be built without a coil. However, it is useless to expect more or less normal performance and acceptable quality of the resulting drink from such a device. Good moonshine is obtained only when alcohol vapor passes through a condenser with the correct organized system cooling. In this case, the material of manufacture of the moonshine still’s coil, the diameter of the tube, size, wall thickness, and location of the refrigerator in space are important.

What's better? Should I buy a ready-to-use distiller or try to assemble it myself? The first option is more reliable and simpler, the second? more profitable. Moreover, in practice, making a coil (condenser) for a moonshine still turns out to be not as difficult as it looks in theory.

Geometric dimensions

Length, diameter, thickness of the tube? parameters that primarily affect the rate of condensate formation and distillation of alcohol-containing liquid. The larger the area of ​​contact between the vapor and the cooling surface, the faster the process proceeds. The thinner the walls of the coil, the higher its thermal conductivity and, therefore, the higher the condensing capacity.

This means that it is better to choose a larger length and diameter (internal cross-section) of the tube, and what about the wall thickness? slightly less. However, such a decision will not be entirely correct. A tube that is too long will increase the hydraulic resistance along the vapor path, as a result of which the distillation speed will automatically decrease.

To achieve optimal balance, it is recommended to make a coil from a tube 1.5-2 m long. This means that this should be its size before curling, and not the length of the finished coil. What are the optimal dimensions for the internal diameter of a capacitor? 8-12 mm.

Thin walls. On the one side? ok, on the other hand? Not good. The fact is that during the curling process they are easily damaged, and the service life of the fragile structure is shorter. In addition, the thermal conductivity of a coil with thin walls at the moment of contact of two media (steam and condensate) sharply decreases, regardless of the diameter of the tube and the material of its manufacture.

What, in this case, should be the thickness of the walls of the moonshine still cooler? The most suitable size is considered to be 0.9-1.1 mm, no more and no less.

Material of manufacture

Important characteristics of the material for making a coil? good thermal conductivity, non-toxic composition, no reaction upon contact with alcohol vapor. These requirements are met by copper, aluminum, brass, food grade stainless steel, silver, glass. The degree of thermal conductivity is most often
metals and alloys used in decreasing order:

• silver? 429 W/(m K);
• copper? 382-390 W/(m K);
• aluminum? 202-236 W/(m K);
• brass? 97-110 W/(m K);
• stainless steel? 20 W/(m K).

Not any stainless steel is suitable for making a coil, but only food grade. In addition, during processing and welding, the composition of the alloy changes and it is unknown how the metal will then react to contact with an aggressive environment, which is an alcohol-containing liquid.

Aluminum tubes are also a good option, but they are inferior to copper and brass tubes in terms of service life. Silver? metal is expensive. It is not advisable to use it in the manufacture of a homemade distiller.

Thus, it is most practical to make a coil for a moonshine still from copper. This material is not difficult to obtain, it has a fairly high thermal conductivity, is easy to process, and does not release toxins when in contact with alcohol.

Glass? the material is non-toxic, with sufficient thermal conductivity, 1-1.15 W/(m? K). But at home it is not possible to make a coil out of it. Therefore, it is best and easiest to buy a glass capacitor at a laboratory equipment store.

Location in the diagram

Depending on the model and configuration of the moonshine still, the refrigerator may be located in general scheme horizontally, vertically or at an angle. Most rational option for moonshine? vertical capacitor connection diagram. In this case, the liquid flows down the tube by gravity, without interfering with the movement of steam.

Let us clarify that vertical coolers are either ascending or descending. It is more practical to use a downward system, in which steam enters the refrigerator from above. In the rising
In the coils, the vapors of the distilled distillate are fed from the bottom up, which creates additional resistance to the movement of the condensate.

Cooling system

While the moonshine still is operating, the coil must be constantly cooled. Cooling can be air, but in this case it will be necessary to make complex design with a cooler, fan, etc. You can use ice or snow as a coolant, which also requires additional effort and material costs in the manufacture of the coil cooling system. In addition, get a large number of ice or snow is not always possible.

The easiest way to cool the coil is with water. It should be taken into account that water cooling systems can be closed or open. In an open system, water circulates constantly; in a closed system, cooling is carried out by a certain amount of water, which is poured into the tank before the distillation of moonshine begins.

Advantage of closed systems? simple design. But at the same time, the tank needs to be made large enough in volume. In addition, when water comes into contact with the warm walls of the coil, it quickly heats up, so that after a short time the distillation of the distillate has to be stopped.

Open cooling systems are more convenient to use. Firstly, do they cool a coil made of any material and any diameter much more efficiently? The distillate will always be cold at the outlet. Secondly, the refrigerator body with open system cooling can be made compact, which makes assembly, operation and storage of the unit more comfortable.

An indispensable condition when organizing a water cooling system for the condenser of a moonshine still? counterflow mode or reflux condenser. This means that water should enter the vertical tank from the bottom and exit from the top. In order for cooling to be uniform, the water flow must be directed towards the movement of the distillate along the coil tube.

Manufacturing technology

The dimensions, material, and diameter of the coil tube were discussed above. Now you need to decide what kind of housing to make for the refrigerator of the moonshine still.

It is most convenient to use under the tank sewer pipes made of plastic, metal-plastic. They are not difficult to get, easy process, install fittings for water supply/discharge, ensure connection through adapters with a distillation cube or steam chamber. Optimal size cross-section of such a pipe? 75-80 mm.

The sequence of manufacturing a moonshine still cooler:

1. The cavity of the coil tube is filled with any bulk material so that the metal does not flatten during the curling process.
2. The ends of the tube are clamped, sealed or plugged with wooden pegs.
3. Gently wind the tube around any hard object cylindrical with a cross section of 35 mm. Distance between turns? approximately 12 mm.
4. The spiral-curled tube is freed from the filler and washed with water.
5. 2 holes are cut out on the cooler body, and a pipe (fitting) is installed in them for supplying and draining water. The holes for the fittings should be located at the level of the spiral part of the coil.
6. The coil is installed inside the housing; the tube is attached to the inner surface of the walls with superglue in 2-3 places.
7. The ends of the body are covered with round sheets of tin and glued around the perimeter with the same superglue. The remaining voids are filled with paper.
8. The ends of the refrigerator and the connection points to the body of the fittings are sealed epoxy resin with a silver coin.

After a day (time for the compound to harden), a homemade condenser with a flow-through cooling system will be ready for use. Refrigerator performance similar design depending on the heating power, the average is 3-4 liters of distillate per hour.

Bending copper pipes is a technically simple task, but it requires attention and accuracy from the performer. Copper, as a fairly plastic material, is easy to mechanically influence, and therefore the pipe can easily be bent at home using human physical strength. But accuracy is very important, because If the load is exceeded, the metal may deform and become unusable.

To bend a copper pipe, you do not need complex equipment: all the work can be done at home using simple devices, for example, a regular spring or river sand or using special tool– pipe bender.

Copper pipes are often used for arranging interior and apartment buildings. utility networks. Hot and cold water supply and heating system based on copper proves to be durable and holds up well thermal energy coolant.

During installation of a system based on copper pipes, it is necessary to change their direction and lead it around obstacles. Sometimes plumbers use flange and coupling connections, tees and elbows, but in practice they reduce the reliability of the system and leak over time due to wear of the seals.

Bending pipes maintains the tightness of the water supply, giving it the required shape. You can physically bend the pipe manually: the thinner the diameter and wall, the easier it is to be mechanically affected.

Important! Essentially, pipe bending is stretching the metal surface by outside bending and its compression - on the inside. If you apply more force to the pipe than required, the surface may become deformed, creating a wavy section where the metal structure is less strong. In this case, it will be almost impossible to restore the original structure of the pipe.

Methods for bending copper pipe

For manual bending of a pipe made of any metal, always use heat. The metal surface is heated using gas burner or blowtorch at the bend. Once the required temperature has been reached, the pipe can be carefully adjusted the required form, carefully bending it at the required angle.

Copper products are in great demand in the field of housing and communal services, namely in the arrangement of water supply and heating networks, as well as in the conduct of various repair work. Copper tubes are integral components of the heating system when installing heated floors. Popularity of this chemical element due to its excellent characteristics: strength, flexibility and corrosion resistance. And since copper products are laid mainly at a certain angle, the information is how to bend copper tube at home - for many it will be very useful. It is worth immediately noting that you can bend a pipe without a pipe bender, this is very convenient in many cases.

Spring to the rescue

For this procedure, regardless of the bending method, a heating instrument will be needed. Therefore, work should be carried out on fresh air or in a well-ventilated area. Great option there will be a yard or garage with an open gate.

There are several methods of bending at home, but they all differ in the level of complexity, price of materials and the use of specialized equipment.

The most common method is to bend a copper tube using a steel spring, which must consist of frequent turns and a thick wire, and its diameter should be smaller than that of the tube. This condition is necessary so that the spring easily enters the product. Most best option, when the lengths of the products are approximately equal. In the case of a short spring, you will need a piece of wire that is attached to it, and then the whole thing can be easily removed.

Many people do not know how to bend small diameter copper tubes. In this case, the size of the spring must exceed the diameter of the pipe that will fit inside it.

Next, the workpiece is heated using a heating device. A gas heating pad or blowtorch is suitable for these purposes. By the change in color of the pipe, you can understand that it is heated well enough and has become plastic. Now you can easily give the copper tube any shape and you can leave it to cool.

Do not forget that you can remove the spring from the pipe only after final cooling.

You can bend pipes using sand

The next method - how to bend a copper pipe at home - is quite simple, because... no steel springs or specialized devices are needed. The steps are the simplest - heat the tube and bend it.

But in order to avoid deformation of the copper product due to its increased flexibility, it is better to use useful advice from experts:

1. Prepare a supporting surface, a heating device, a couple of pieces of wood with diameters corresponding to the size of the future pipe, and sand.
2. Construction material To avoid deformation when bending copper tubes, it must be dry, sifted, river, without bulky components.
3. Plug one edge of the workpiece with a wood plug, fill the hollow space with sand, shaking the pipe repeatedly for more uniform filling.
4. Use the remaining stopper to seal the second edge of the tube.
5. Then heat it and, leaning on a solid base to avoid tearing the walls of the product, carefully bend it.
6. Do not overheat the pipe due to the pressure of sand on its walls.
7. When the product has taken the appropriate shape, it must be immersed in cold water.
8. After the copper pipe has completely cooled, remove the plugs and pour out the sand.
9. It is advisable to blow ready product to remove any remaining debris.

Application of pipe bender

Let's consider another way - how to bend a copper tube without applying any additional effort. A reliable assistant in this matter will be a special device - a pipe bender, thanks to which you can save time, speed up and facilitate the bending procedure itself.

What kind of device is this? This is a mobile tool that bends a pipe according to a given parameter, fixing one end of the pipe and moving the other. And the bend point is always in a stable position.

All pipe benders, according to their operating principle, are classified into:

1. Lever (manual), including a pair of levers with a shoe and a bending template. To set the desired angle, you need to take a reference from the marks on the surface of the levers. Then fix the workpiece in the bracket, combine the zeros and do the main work. Using this pipe bender, you can bend a pipe at almost an angle of 180° at home.
2. Hydraulic, which relate to devices professional level and bend the tube much more quickly than the previous ones. Thanks to hydraulic principle operation of a pipe bender, you won’t have to strain yourself too much.
3. Electrical, which are used in industrial production or business. With the help of such devices it is quite possible to fulfill a serial order. Electric pipe benders are powered by an electric drive and are very similar to their manual counterparts. The tubular product is placed in a bracket and bent according to the parameters that are specified by special segments.

Having understood the topic - how to bend a copper pipe, you still have to choose the right equipment in accordance with the parameters of the workpiece to be bent. For example, a manual pipe bender, spring or sand will come in handy when bending a product of small length and diameter. But only hydraulic and electric tools can change the profile of a large workpiece.

How to bend a copper pipe using the spiral method

Sometimes bend pipes in the usual ways fails due to non-standard parameters, for example, the workpiece is square rather than cylindrical. To understand how to bend a copper pipe in this case, you need, first of all, to purchase a rubber mallet and a pair of supports. Then fill the tube cavity with sand or fill it with ice (in winter); install the product with its ends on supports; warm up the bend; Using a mallet, give it the appropriate shape.

Often craftsmen have to bend a copper pipe into a spiral to order.

To do this you will need:

1. Fire the workpiece for greater flexibility.
2. Let cool completely.
3. Pour sand inside the pipe or freeze water there.
4. Bend the product by hand or using a blowtorch, which will significantly speed up and facilitate the bending process.

When bending a copper pipe, you can use a cylindrical support, and then the spiral will turn out perfectly smooth.

As you can see, methods for bending copper pipes, a lot has been invented. But no matter which one you choose, you must strictly adhere to the basic rules. First of all, perform all actions carefully and slowly to avoid deformation and rupture of the pipe walls. Sometimes an unexpected sudden movement can lead to negative irreversible consequences and product rejection.

Listen to our useful tips, and you can easily bend a copper blank at home for a future plumbing or heating system.