The question of that, how to bend a profile pipe, without using special equipment, many of those are asked, who is going to build a greenhouse on his plot. Such structures, made of bent pipes, not only do they transmit much more light, but also have high stability and durability, compared to wooden bar constructions. It seems, what to bend a professional pipe, creating an arched structure from it, not so easy, but, if you understand the features of this process, it is possible to do it effectively, using the simplest devices.
Self-made constructions from profile pipes are characterized by good reliability and low metal content
What is the complexity of flexible profile rolling
The essence of flexible metal, regardless of the shape of its profile is, that the profile pipes are given a partial or complete bend. This technological operation is performed in two ways: affecting the bending pipe only by pressure or additionally heating the pipe section, in the area of which the bend is performed. During the bending, two forces act simultaneously on the metal pipe:
- compression force (from the inside of the bend);
- tensile strength (from the outside of the bent area).
It is the influence of such diverse forces that causes difficulties, characteristic of the process of bending any profile pipes.
- Segments of pipe material, which in the process of bending changes its shape, may lose the alignment of their location, which leads to, that individual sections of the pipe will be located in different planes;
- The wall of the professional pipe, located on the outside of the bend and stretchable, may not withstand the load and burst.
- The inner wall of the pipe, compressible, may be covered with folds, resembling corrugation.
Technical characteristics of profile tubes
If you do not take into account the subtleties of such a technological process, then instead, to bend the profile pipe, you can just crumple the product, irrevocably ruining it.
That this did not happen, it is necessary to consider not only the characteristics of the pipe material, but also its geometric parameters - the dimensions of the section, wall thickness, radius, on which it is necessary to perform a bend. Knowledge of the above will allow you to choose the appropriate technology and bend the pipe correctly, without crumpling it and without getting a corrugated surface.
The need to account for the profile
Products are included in the category of profile pipe rolling, having a different cross-sectional shape - round, square, oval or flat-oval. Despite such diversity, rectangular or square pipes are preferably used for the construction of a greenhouse or canopy. It has to do with that, that on their flat walls it is much easier to mount an external covering.
The range of modern profile pipes is very diverse. Their geometric parameters, the main of which are the cross-sectional area and wall thickness, determine the plastic capabilities of the product. The latter is characterized by such an indicator, as the minimum allowable radius of curvature. This parameter allows to define, to what minimum radius it is possible to bend a professional pipe, so that it is not damaged.
Avoid common mistakes, leading to damage to the workpieces
To determine this parameter of a pipe with a square or rectangular profile, as the minimum bending radius, it is enough to know the height of her profile. If you are going to bend a profile pipe with a cross section in the form of a rectangle or square, the following recommendations should be followed.
- Pipes, the height of the profile which does not exceed 20 mm, can be bent in areas, whose length exceeds the value, equal to 2.5xh (h - profile height).
- Ware, whose profile height exceeds 20 mm, can be successfully bent in areas, the length of which corresponds to 3.5xh and more.
Minimum bending radii of steel pipes
Such recommendations will be useful to those, who with his own hands is going to bend the profile pipes for that, to make racks out of them, canopies and various frame constructions. With, however, should be borne in mind, that the possibility of high-quality bending of pipes is influenced by the thickness of their walls. Ware, whose wall thickness is less 2 mm, it is better not to bend at all, and if necessary to create structures from them to use welded joints.
At home, bend the professional pipes, which are made of carbon or low-alloy steels, it is possible only taking into account certain nuances. Such pipes after bending can spring back and return to its original state, therefore, the finished structures must be re-adjusted to the template. The magnitude of the spring is characterized by the following parameter of the profile pipes, as a plastic moment of resistance - Wp. This parameter is specified in the accompanying documentation (the lower it is, the less will be otpruzhinivaet professional pipes in the process of their flexibility).
Features of the most popular methods of bending pipes
In industrial or domestic conditions, professional pipes are bent as if heated, and in the cold state. Heating, which is produced using a gas burner, significantly increases the ductility of the metal, due to which less effort is required to bend. Pipes of small section can be bent without heating, because they already have good plasticity.
Regulatory guidelines for the use of heating are only available for round products. So, it is recommended to heat the pipes before bending, the diameter of which exceeds 10 cm. In those cases, when it is necessary to bend square or rectangular pipes, it is necessary to be guided by own experience or advice of other house masters.
- Pipes are bent without preheating, the height of the profile which does not exceed 10 mm.
- If the height of the pipe profile exceeds 40 mm, they must be heated before bending.
Before starting work, decide on a flexible method
If you have a pipe bender, with its help you will easily cope with the task of cold bending pipes, the height of the profile which is in the range 10-40 mm. In the absence of such a device, it is necessary to address the issue, how to bend a pipe without a pipe bender, having previously carried out simple tests. They will help you identify, it is necessary to heat a professional pipe before flexible or not. These tests are performed as follows. One end of the pipe is clamped in a vise, and the second is provided with a pipe with a large internal cross-section. If by means of such shoulder it is possible to bend the pipe clamped in vices, you can perform this process without preheating.
The bending of pipes by various methods is well demonstrated by the training video, however, it will not be superfluous to study this process in detail in advance.
Flexible professional pipe with preheating
To bend the profile pipe with your own hands by the hot method, it must be pre-filled with sand. This will make the bend more qualitative and uniform. Because you have to deal with hot metal, all work should be performed in tight tarpaulin gloves. She is flexible, with the implementation of which you can see the video, performed in the following sequence.
- Both ends of the profile pipe must be closed with plugs, which are made of wooden bars. The length of such plugs should be in 10 times the width of their base, which, in turn, should have an area, twice the area of the hole in the pipe, which is closed with their help.
- After fitting the plugs under the inner section of the pipe on one of them is performed 4 longitudinal grooves, which are necessary for gas removal, accumulating in the pipe when heated fills its sand.
- Section of the professional pipe, which you plan to bend, must be pre-annealed.
- Medium-grained sand should be used as a filler for the pipe. If there is no cleaned construction sand, you can take any, even from a children's sandbox, but it should be prepared accordingly. So, the sand is first sifted through a sieve the size of a cell 2-2,5 mm, to remove gravel and small stones, and the final sieving is performed on a sieve with the size of the cell 0,7 mm. Final sieving is necessary for this, to remove dust inclusions from the sand, which can bake when heated.
- Prepared sand must be calcined at room temperature 150 degrees Celsius.
- Before filling with sand, one end of the pipe is closed with a plug, on which there are no exhaust ducts. A funnel is inserted at the other end, through which the prepared sand is poured in portions. That sand evenly and densely filled all internal cavity of a pipe, when filling it is necessary to knock on the walls of the product, using a wooden or rubber mallet.
- After the pipe is completely filled with sand, its other end is also closed with a plug.
- Area, which will be heated for further bending, should be marked with chalk.
- The pipe must be fixed in a vise with a template or in a pipe clamp. This is important, to weld, if it is on the surface of the product, was on the side. This requirement must therefore be complied with, that the weld is undesirable to compress or stretch.
- Pipe section, pre-marked with chalk, heated to red with a gas burner. After complete heating, the pipe is neat, without making sudden movements, bend in one go, applying force strictly in the vertical or horizontal plane.
- After cooling the bent pipe, the result is compared with the template. If all is well, then remove the plugs from the ends of the product and pour the sand.
The right technology of manual bending "hot"
This method, which is easy to implement at home, best used in those cases, when a single angular bend must be formed on the professional pipe. Repeated heating of the metal can lead to loss of its strength, and this cannot be avoided, if you bend the pipe to use it as an arch element.
How to bend a pipe without preheating
Bend the profile pipe yourself, without preheating it, it is possible as with a filler, and without him. Do not require filling pipes with sand or rosin, the height of the profile which does not exceed 10 mm.
The nuances are flexible thin-walled pipes of small dimensions
There is another technique, which involves the use instead of a filler spring with a tight coil winding, which is inserted into the inner cavity of the professional tube and protects the walls of the product from deformation, as well as from excessive changes in their thickness during bending.
Drawings and details of mechanical pipe bender for profile pipes
The design of the elementary pipe bending device is simple and available for self-manufacturing
Tim, who needs to bend profile pipes with their own hands, without preheating them, you can use the training video and the following simple recommendations.
- You can get the necessary bend on the profile pipes with the help of the simplest devices - vices, mandrels, bending of plates.
- You can use a manual pipe bender for products with a round profile. The work rollers must be redesigned in this device, the shape of the recess in which should correspond to the profile of the pipe.
- It is possible to bend pipes most effectively and precisely by means of the profile bending machine, which can be purchased or made with your own hands.
Devices for bending pipes
The question is, how to bend a pipe without a pipe bender, will not cause difficulties, if you use the simplest devices to perform this operation. It is possible to carry out cold bending of pipes by means of such devices.
- In those cases, when you need to bend soft (aluminum) or a steel pipe with a profile height of not more 10 mm, a horizontal plate with holes is used, in which stops are inserted - metal pins. By means of these pins bending of products on necessary parameters is also carried out. This method has two serious disadvantages: low precision flexible, as well as that, that when using it it is necessary to make considerable physical efforts.
- Products with profile height 25 mm it is better to bend by means of roller devices. The pipe is securely fixed in the vise, and to that part of it, which must be bent, the effort is applied with a special roller. This device allows you to get a better bend, but also requires physical effort.
Version, what is called, in a hurry. The long lever of this extremely simple device allows you to handle fairly thick pipes
Basic devices will help to make a one-time bend of a pipe
For the formation of steel or aluminum bends with a large radius of curvature using fixed round templates, on which special clamps for fixing of a product mount. On such a device, the pipe is also bent by hand, with effort putting it in the groove of the template, the shape of which corresponds exactly to the required bending radius.
Plywood and metal staples are everything, what is needed to make a bending template
flexible plate
To effectively bend steel or aluminum pipes at home, you can make an upgraded bending plate, using the following recommendations.
- The role of such a plate is played by the panel, which is cut from thick sheet metal.
- Panel, performed as follows, welded to the rack, which is mounted on a special pedestal.
- Two holes are drilled in the panel, required to install the bolts, employees stops for a profile pipe.
- A special nozzle is installed on one of the stop bolts, by means of which the radius of a bend is regulated.
- To ensure the alignment of the pipe sections, adjacent to the bend, a metal plate is placed over the workpiece, bolted.
Scheme of the stand for bending profile pipes
The principle of making a simple homemade bending device
At that moment, when you will not use such an upgraded pipe bender, its pedestal can be adapted to perform various metalwork operations.
Flexible on the mandrel
For flexible profile pipe products at home, whose wall height does not exceed 25 mm, you can make a special mandrel. For this purpose it is better to use an oversized workbench, on the surface of which there will be enough space for such a device. To select the optimal location of the item, which fixes the bending pipe, often located holes are made at one end of the machine. A special template is responsible for ensuring the required bending radius of the professional pipe, which can be made of thick plywood or a metal corner, if you are going to use it often.
Bending of a profile pipe by means of a mandrel
use of profile bending
Of course, if you own a significant amount of work on bending profile pipes, it is better to make a special machine for this, whose drawings are easy to find on the Internet. We will not discuss this issue here, as discussed in more detail in the articles at the links below.
Related articles:
> Self-made pipe bender for profile pipe - scheme, drawing, video
> Making profile bends with your own hands - drawing a homemade machine
> How to make a pipe bender with your own hands - drawings, photos and videos
One of the many options for homemade profile bender
Do not do without such a machine in that case, if you need to bend pipes with a large profile cross section. The main working bodies of such a machine, which has a wide versatility, there are three rolls, two of which are fixed, and by changing the position of the third adjust the bending radius of the product. As the drive of such device the chain transfer and the handle is used, which is rotated by the operator.
Obviously, that device options, that allow to bend effectively profile pipes for production of the greenhouse, canopy or other structures, quite a lot. Having considered these options and choosing one of them, which optimally meets your capabilities and needs, you can always provide yourself with a convenient and inexpensive pipe bending device.