Flexion copper pipes- a technically simple task, but it requires attention and accuracy from the performer. Copper, as a fairly plastic material, is easily mechanically affected, 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.
No need to bend copper pipe complex equipment: All work can be done at home using simple devices, for example, an ordinary spring or river sand, or using a special tool - a pipe bender.
Copper pipes are often used for arranging interior and apartment buildings. utility networks. Hot and cold water supply, 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 form. You can physically bend the pipe manually: the thinner the diameter and wall, the easier it is to be mechanically affected.
Important! Essentially, bending a pipe involves stretching the metal surface on the outside of the bend and compressing it 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. Metal surface heated with 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.
During construction, repair and installation work pipes are used for laying sewers, gas pipelines, water supply, ventilation, sewerage, etc. Depending on the location of operation, pipes from different materials, various thickness, diameter and length. However, it is not always possible to use an elbow or adapters. In such cases, you have to bend the pipe, as a result it can be damaged or even ruined. Since a material such as stainless steel has sufficient strength, has a long service life and is not affected by moisture, it is often used during installation work. Therefore, in this article we will look at how to bend a stainless steel pipe.
The bending process itself metal products can be divided into two types. Temperature, when the workpiece or part of it is heated or cooled with subsequent bending. Mechanical, when the workpiece is acted upon with a certain force using special devices or bending it by hand. It is worth noting that stainless steel is a relatively technologically advanced material and there are usually no difficulties during operation.
Pipes from of stainless steel Do not bend with preheating (for example, a gas torch or blowtorch).
Bend as a negative factor
Pipe bending is negative factor For performance characteristics. Take place various disadvantages, depending on the material, bending angle, bending device and method, internal diameter and thickness of the material. Negative consequences include:
- change in bending radius during operation under the influence of thermal expansion or contraction and mechanical action, resulting in a springing effect;
- reducing the thickness of the outer wall at the bend;
- the appearance of sharp breaks or folds in the form of an accordion on the inner wall of the bend;
- ovalization - a change in the shape of the pipe and the appearance of an oval-shaped lumen;
- increased exposure to corrosion on the inner and outer walls of the bend.
When a substance passes through the internal cavity of the pipe, special pressure is exerted on the outer wall, therefore, when installing in places where liquids flow through high pressures It is recommended to use an elbow, thickening or a pipe with thicker walls. The resulting ovalization also negatively affects the pipes during rapid fluid flow. In such places, there is a narrowing along one axis and expansion along the other, which, in turn, also increases the pressure on the outer wall of the bend. You also need to take ovalization into account when laying pipes in narrow places, since its width at the bend increases.
There are two ways to prevent ovalization and maintain a round shape during cold bending. First, support the walls from the inside using an internal stop. Second, support the walls both from the inside and outside, using an internal and external stop. The internal limiter can be sand, rubber, water, resins or fusible materials carefully compacted into the pipe. The main thing is to securely close the pipe holes so that when pressure increases during bending, the filler does not fall out. If possible, it is recommended to seal the pipe openings tightly.
When using the second method, the integrity indicators are slightly higher, but this requires special mechanical elements or reservoirs, which are usually used when industrial production pipes If you use a more rigid and solid internal filling, more round form lumen, so they are used more often. But when using elastic fillers, outer side less susceptible to stretching.
Bending methods
In production, when it comes to bending stainless steel pipes, cold bending is usually used due to higher profitability, and in cases where hot bending is necessary, it is often more profitable to simply pour the required shape right away. Therefore, the following are methods of cold bending, especially since most technologies are not very different from the hot method.
Bending using two supports
The workpiece is placed between two supports in such a way that the first support holds and the second acts as a load-bearing support. When exposed to a screw or hydraulic press or the jack beyond the second support, bending occurs. This method can be used to bend pipes with a diameter of up to 350 millimeters. The equipment is quite simple and can be used directly at the installation sites.
Rolling
This method is used when you need to get a ring or spiral from a small diameter pipe. The workpiece, with the help of mechanical fasteners and a pusher, moves through rotating rollers, subsequently acquiring the necessary curvature.
Bending by rolling
IN in this case the workpiece is fixed and rolled out in certain places using special balls. A similar process can occur both from the outside - wrapping, and from the inside - rolling. As a result, the pipe takes on a triangular shape with rounded edges.
Reel bending
This method has become widespread in industrial production due to the relative simplicity with low energy consumption and the yield of high-quality products. In this case, internal filling is used, most often it is a metal rope with a diameter 0.1–0.5 mm smaller than the internal diameter of the workpiece. When a rope bends, it can leave a mark on the inner surface of the pipe, so ropes made of thin woven metal fibers of non-hard grades of metal are used. Also, when using this method, lubricant is necessary between the rope and inner surface, which is usually machine oil or anti-corrosion soap emulsion. You can bend pipes with a diameter from 10 to 425 millimeters in different planes. Therefore, for large diameters, the cable is not used, but, if possible, is replaced with a bulk or liquid substance.
Bending by rolling
The method is that a rolling roller moves around a roller or support of the required dimensions, a workpiece is placed between them and a bend is obtained. In a similar way, you can work with pipes with a diameter of up to 150 millimeters with thick walls.
Stainless steel pipes are often used in both industrial and individual construction work. You can bend them by choosing one of many working methods. The choice of a specific method depends on a number of factors: diameter, wall thickness of the product, the presence of special tools.
Bending in industry
There are many techniques used in industry that allow you to bend a stainless steel pipe. We list the most common of them:
These working methods are effective in industrial conditions. However, in the case of individual construction, they are not suitable. In everyday life, manual methods are used to bend a stainless steel pipe.
How to bend a pipe at home
In everyday life, in order to bend a stainless steel pipe, a manual pipe bender is usually used. Most often, this tool is made in the form of a crossbow. This “crossbow” allows you to bend the product by squeezing it in the bending zone.
To ensure that the product does not deform during work, special internal limiters are used. For example, they can be dry sand. A plug is placed at one end of the part, then the product is filled with sand. The sand is lightly compacted by tapping. Then the remaining end of the part is also closed with a plug. Then you can bend a stainless steel pipe around a blank of the required diameter.
The internal limiter can also be a spring. It is manufactured in 
at home. You just need to wind it from wire, the thickness of which is 1-4 mm. It is important to make it such that the spring easily fits inside the stainless steel pipe. So, the spring is placed in the product, then it is bent around the circumference of a metal blank. You can also use a manual pipe bender.
After the work is done, the spring is pulled out by means of a wire previously attached to it, a wire of which one end is left outside. This method will help to bend square-section profile products. In this case, the spring must also be characterized square section.
A bundle of wire can also act as a limiter for working with a stainless steel pipe. The wire is placed in the product until there is no more free space. At the end of the work, it is sequentially removed.
In conclusion we can say that manual method Suitable only for stainless steel pipes, the diameter is no more than 40 mm, and the wall thickness does not exceed 3 mm. If the dimensions of the product that is planned to be bent are larger, special equipment is used.
In fact, bending a stainless steel part is not so difficult if you know the appropriate instructions and rules. To better assimilate the information, you can watch a video that clearly shows the operating algorithm.
Another craft (to order) from the “crazy hands” series. This time - spiral coil (heat exchanger) made of stainless steel. I wanted to make it according to this scheme (long live Paint
Before making it, I looked on the Internet to see who makes such things and how. I was interested in a video on YouTube in which the author winds a spiral heat exchanger coil onto a two-inch pipe using a machine:
I don’t have a machine, so I decided to wind a heat exchanger coil from the same tube as in the video, but manually.
A stainless steel tube with an outer diameter of 10 mm and a wall thickness of 1 mm was found. Almost four meters long. I decided to wind it the same way as in the video above - on a two-inch pipe (I had it in stock).
A small digression.
As for me, winding on a two-inch - perfect option for the DIYer. Now I will explain why. Cooling of the coil was planned to be achieved by running water. This means that a cylindrical casing will be needed, inside of which there will be a coil. For better heat transfer the casing must be selected in such a way that there is space between the spiral turns and the casing wall for water flow (and not just in the center of the spiral winding).
Because with such winding of the coil - the outer diameter of the coil turns will be in the region of 80-85 mm (base pipe for winding = 60 mm, thickness of two turns = 2 * 10 mm = 20 mm, plus a few millimeters will be added due to the slight reverse expansion of the turns), then hands immediately We were itching to use a ready-made 110mm plumbing pipe as a heat exchanger casing.
Now, regarding preparation for winding.
1) While the stainless steel tube is still intact and smooth, it must be cleaned from the inside. Yes Yes. Despite the fact that with outside the tube is clean and smooth - everything inside it could be much worse. What are we doing? We take a thick steel wire (mine was 3mm in diameter) and long enough (at a minimum - a little more than half the length of a stainless tube, then you will have to clean it on both sides). We tightly wrap a wet cloth (or rather a ribbon) onto the end of the wire, and to prevent it from being torn off, we grab the fabric with a thin copper wire. We dip this improvised “kvach” into fine sifted sand (more about it later) and either push the wire with the kvach at the end along the tube, or drag it (depending on the thickness and length of the wire) after the wire. We take out the kvacha - we look at it, we are horrified and we repeat the operation until our quality control department accepts the internal cleanliness of the tube.
Important! The tube must be cleaned before winding. After winding it will be impossible to do this.
Important!! Reel the kvach securely, because if it falls off the wire, you can get a new quest called “Ma-a-a-a-l-a-det! Now get that crap out of the tube.” Use strong wire.
Important!!! There is no need to wet or rinse the inside of a stainless steel tube with water! Because Further according to the plan, filling the tube with sand.
2) Sand. The sand needs to be dry and sifted. It is needed to pack the coil tube. Just like in the video with the machine, we plan out chopsticks from wood, hammer one chopstick tightly into the tube and, using a funnel, pour sand portionwise into a vertically standing tube while tapping the tube from bottom to top. After the tube is tightly packed with sifted sand, the second cap is clogged. The tube is ready to be wound.
Important! Sand is necessary to protect the tube from crushing the walls during the winding process. Poor/uneven sand packing will most likely lead to improper deformation (collapse of the walls) of the tube during winding.
Winding.
There are two (main) ways to wind a heat exchanger manually from a stainless tube.
Method one - we fix the improvised shaft (2″ pipe) horizontally and rotate it, thereby winding a stainless steel tube with sand around it.
The second method is to rigidly fix the shaft vertically and wind a stainless tube around it, moving with the tube in a circle.
Because With a four-meter tube you can’t turn around much, so the first option was chosen. And because lathe no - then on an improvised workbench, sliding bearings for a two-inch pipe were knocked together from wood:
Important! The upper height limiter (in the picture there is a block with the inscription tree) for such bearings should be equal to the diameter of the shaft (pipe 2″) + one diameter of the wound tube (10mm).
Because a previously cut 3/4″ piece was located perpendicular to the shaft - then by inserting a suitable fitting into it, I got a lever for turning the shaft.
Important! For correct winding, it is necessary to properly secure the tube to the shaft. You can, as in the video (see above), weld a counterbored nut, insert a stainless tube through the nut, bend the tube 90 degrees and start winding. I didn’t want to get involved with welding (at that time) - so in the shaft itself (2″ pipe) two holes were drilled through the edge, through which a U-shaped metal loop with twist with reverse side, which fixed the end of the tube. For additional rigidity, I wound the beginning of the tube with thick wire to the shaft.
Next, slowly, with four hands (one holds the tube, the other turns the shaft using a lever), winding is done, after winding, the choppers are taken out, sand is poured out, an extra piece of tube is sawed off and we get something like this spiral heat exchanger(the quality of the photo is disgusting, because it was taken on quick hand and telephone):
As for me, the result of making a coil with your own hands is very, very good, for the first time. It's nice to even hold it in your hands. However, in order for the heat transfer process to be more efficient, the coil turns must be carefully moved apart (so that water also circulates between them). To do this, I had to plan about twenty wedges from dense wood (pine is not suitable) and using a hammer, gradually driving the wedges into different sides spirals, move apart the turns of the homemade heat exchanger.
Important! At the very beginning, the coils noticeably resist the wedges, so take care of your fingers and nails.
Important!! It is better to move the coils apart in several passes, gradually increasing the distance between the coils and constantly monitoring so that the coil itself does not move to the side:
After all these manipulations we get this beauty (duct tape for scale):
This beauty took three meters of stainless tube. Now it was necessary to make the heat exchanger casing.
Heat exchanger casing.
As was written earlier, it was planned to use a gray plumbing pipe with a diameter of 110 mm under the casing. Therefore, the following components were purchased: 0.5 meters of 110mm plumbing pipe, an adapter coupling for a 110mm pipe, two plugs for the same pipe, two 3/8″ fittings, a meter rod with an 8mm thread. An adapter coupling is needed because the 110mm pipe has different diameter at the ends and plugs can only be installed on one side. True, there is a bonus - the casing becomes collapsible.
Seals.
If the fitting has a threaded part with a nut, thanks to which it can be secured in the casing body through rubber seals, then the tube of the stainless coil must somehow be passed through the plastic casing, and in such a way that water does not leak. For these purposes, I had to make a cunning homemade rubber seal (2 pieces) (see picture) with a groove for plastic.
Using a sharpened large-diameter tube, I cut out two cylindrical seals from thick sheet rubber (thickness about 14mm). Then using the smaller tube (d< 10мм) в каждом уплотнении были сделаны центральные отверстия (на рисунке через них проходит штрихпунктирная линия). Затем уплотнения были насажены на подходящий болт, болт был зажат в дрель и при помощи обломка квадратного надфиля на резиновых уплотнениях были проточены (проточены, громко сказано, скорее, протёрты) канавки под пластик:
Important! Hole in plastic cover plumbing pipe was drilled in such a way that the rubber seal was inserted into the plastic very tightly. Thus, after insertion, the central hole (which was already made with a diameter of slightly less than 10 mm) was additionally crimped. When inserting the coil tube, the rubber is sandwiched between the coil tube and the plastic hole, thereby sealing the joint. No additional sealants (silicone, etc.) were used.
Casing assembly.
We insert the seals into the holes in the plumbing pipe covers. In the same covers, we insert fittings for supplying and discharging cooling water. There is a rubber seal under the fitting nuts for sealing. Next, all rubber seals of the 110th plumbing pipe and couplings are coated with soap for ease of assembly. Then a pipe is inserted into the coupling, a coil is inserted into the pipe, and plumbing pipe caps are placed on both ends of the coil (yes, with those homemade seals). Then, moving the covers along the ends of the coil, we insert the covers into the pipe and coupling. For reliability, I sawed a meter-long stud into two parts and with these half-meter studs I tightened the entire structure with nuts.
This is actually what happened in the end ( general form- upper part of the photo, heat exchanger output - lower left part of the photo, heat exchanger inlet - lower right part of the photo):
A test run showed that the heat exchanger works successfully. The heat transfer is huge. The water flow can be set to a minimum. It looks like you don't have to worry too much about strong sealing. Since water enters the casing and exits through fittings of the same diameter, the water pressure inside the casing should be minimal.
Mon. Alcohol and its solutions, regardless of concentration and quantity, cause enormous damage to the body. I don’t use it and don’t recommend it to others. The coil was assembled to order.
PPN. There are (on the Internet) other ways to seal the joints of a coil tube and a plumbing pipe - for example, using epoxy resin, but then the heat exchanger casing becomes non-removable.
There are special technical devices that allow you to bend a copper pipe
Need to bend copper tube occurs at the time of construction and installation work related to the installation of heated floors, sewerage or water supply. The choice in favor of this material is due to its wear resistance and versatility. Even with long-term use, copper is practically not subject to corrosion. At the system design stage, all pipe bends are taken into account. This will allow you to complete the installation with pinpoint precision. The less “congestion” is formed along the path of the liquid, the higher the efficiency of the system.
Builders advise not to neglect safety rules. All work is carried out in a well-ventilated area or in outdoors. The easiest way to bend a copper tube is to use a spring. The latter must be made of high quality steel. Its core is characterized by maximum thickness and frequent turns.
When bending a copper pipe, you should not forget about safety precautions Before starting work, you need to make sure that the spring you are using passes freely through the bent tube. It is better when the spring and tube are approximately the same size.
The further procedure is as follows:
- Before starting manipulations, you need to make sure that the spring can be easily removed from the pipe;
- Preheating of the workpiece is carried out using a gas burner or blowtorch;
- The thermal effect continues until the tube becomes easy to bend.
- After that, you give it the desired shape with your own hands.
- The work is completed by placing the product in a cold environment to cool.
On last stage Newbies make a common mistake. Do not remove the spring from a hot pipe, otherwise it will become deformed. You need to wait until it cools down.
Universal method using sand
It happens that there are no pipes at hand and construction equipment. In this case, you can use sand at home. Before starting work, you need to pay attention to physical properties sand and the pipe itself. It is enough to make even a minor mistake for the copper tube to take on the wrong shape. The first thing you need to find is a supporting surface that will withstand the load. Second place on the list of necessary things is given to 2 pieces of durable wood.
Once everything is collected, you can start working:
- For work, only sifted river sand without foreign inclusions is used;
- Fractions should be as small as possible;
- Sand for bending tubes must be dry;
- One end of the tube is plugged with a stopper made from a piece of wood;
- Sand is poured into the cavity;
- During this procedure, the tubes must be shaken slightly so that the sand is distributed evenly;
- As soon as everything inner space turned out to be filled, the second end is plugged with a stopper;
- The tube is slightly heated and then bent;
- The support surface is intended to simplify the task.
Before bending a copper pipe, you should first watch a training video As soon as the pipe gives way, heating is immediately stopped. Once everything is completed, the pipes are laid in cold water. After this, both plugs are removed. Sand spills out.
When to use a pipe bender
It happens that the spring and sand cannot cope with the task. In this case, heavy artillery is used. A device that saves time is called a pipe bender. The mobile unit changes the shape of the pipe based on the parameters specified by the person.
The whole process comes down to fixing one end of the tube and manipulating the other. The main thing is that the bend point is correctly fixed.
Before you start, you need to choose the right tool. There are lever and hydraulic pipe benders.
Their characteristics are as follows:
- Manual or lever - its design includes 2 levers, a bending shoe and a template. There are marks on the surface of the lever, on the basis of which the required angle is set. The tube is fixed in the bracket so that the zero marks are aligned. The maximum bending angle is 180 degrees.
- Hydraulic - refers to professional equipment. They can get the job done several times faster than their manual counterparts.
Pipe bender is quite expensive The use of a pipe bender is justified when we're talking about about a significant amount of work. Mobile device optimizes time costs provided the right choice. Manual type suitable for household needs, and hydraulic – for industrial ones.
Spiral bending at home
It can be difficult for beginners to bend a brass or copper tube into a spiral. To solve the problem you will need a rubber mallet and 2 supports. Sand or, less desirable, ice is poured inside. The tube is placed with 2 ends on the support points. After this, the bend point is gradually heated. As soon as the material begins to yield, a mallet is taken into hand. With its help you need to bend the pipe. Each action must be as balanced as possible, otherwise the material will simply crack.
After bending, the pipe becomes more compact and practical
The following recommendations will help reduce the likelihood of errors:
- If the tube is too hard, it needs to be burned a little to make it more flexible;
- As soon as it has cooled, filler is poured into it, after which it is easier to bend it at the required angle;
- The use of a cylindrical support will give the product an even shape.
Laying a sewer or water supply requires increased attention to the quality of the pipes used. You can give them the required shape yourself or using hydraulic equipment. Regardless of your choice, you need to be extremely careful. The pipe surface should not be exposed to excessive heat. Do not hit it too hard, otherwise the pipe will simply crack at the bending point.
