It’s possible without welding: 5 easy ways to connect a profile pipe

Methods for connecting profile pipes

Welding is most often used to create permanent connections of profile pipes. Its type is selected depending on the material from which the pipe products are made, the availability of equipment, and the working conditions. Welded seams are characterized by strength, reliability, and durability. However, in some cases it is necessary to create a detachable connection of profile pipes without welding with the possibility of its dismantling while maintaining the integrity of the elements. For this purpose, bolts, connecting elements, and “crab systems” are used.

Connecting a profile pipe using “crab systems”

This system is used to create small, light-loaded structures. It consists of clamps, bolts and nuts. The required tool is a wrench.

For the manufacture of clamps and fasteners for connecting profile pipes, a cold-rolled sheet 1.5 mm thick, coated with a protective zinc layer or powder paint, is used. Clamps consist of two halves, tightly covering the profile pipes inserted into them. These halves are fastened together with bolts and nuts. Popular system sizes: 95x65 and 95x95 mm.

This method of connecting profile pipes allows you to quickly assemble and dismantle a greenhouse, gazebo, outdoor bathroom or shower stall. Limitation: Can only be used for small-diameter products and only at an angle of 90°.

Characteristics of this type of docking:

strength, slightly inferior to that of welded joints;
Efficiency of assembly, low cost of installation work;
no need to use expensive tools;
no special requirements for worker qualifications.

Clamps for attaching profile pipes to enclosing structures

This fixture for square or rectangular tubular products consists of two components. One element is screwed into the ceiling or wall, a pipe is inserted into it, secured by the second element and bolts.

This type of fastener is called a “clip”. There are two options for its design: corresponding to a specific range of pipes or adjustable.

How to connect a profile pipe without welding using fittings, bolts and other elements?

When installing pipe products with a square or rectangular cross-section, manufacturers offer special fasteners - fittings. They can also be made in the form of tees and crosses. Most often, fitting connections are strengthened by welding.
Using a strip of steel bent in the shape of the letter “L”, you can connect two profile pipes at an angle of 90° with bolts.
Another way to join pipes of the same cross-section is to make a connecting element using welding. You will need a piece of pipe, the cross-section of which allows you to insert the profile products to be connected inside it. The connecting profile is cut into two parts, at one end of which a 45° bevel is made. These elements are welded to form a right angle. At the edges of the formed corner, holes are made, the diameter of which should not exceed ½ the width of the profile wall. Nuts whose diameter exactly matches their diameter are attached to the holes by welding. Holes of the appropriate size are also made at the ends of the connected profile pipes. Such connections can be made adjustable.

Features and characteristics

Crabs are staples with a fastening system. They are made of galvanized sheet metal, the thickness of which must be at least 1.5 mm. They mainly found their application in the installation of rolled pipes with a cross-section of 20x20, 20x30, 40x40 and 20x40 mm. Fastening is carried out using clamping force. The bolts are tightened on the crab itself, and not on the pipes being connected. Because of this, this design has low tensile strength, that is, the fixed pipe, with some effort, can be removed from the connecting element.

An outdoor metal structure constructed using fastening crabs is continuously exposed to adverse conditions (wind, precipitation, temperature changes, frost). Gradually this will lead to loosening and loss of stability of the structure. Therefore, fasteners must be periodically checked, tightened and, if necessary, repaired.

This type of fastener allows you to create a frame structure that can be assembled and disassembled when necessary.

Among the disadvantages of connecting crabs, one can note the impossibility of their use in the installation of pipes with a large diameter. Parts can only be joined at an angle of 90°.

Choosing a mounting method

How to connect a metal-plastic pipe to a metal one
When choosing a connection method, you must take into account the purpose and features of the assembled structure:

the crab system is used to connect square pipes without welding and small-section rectangular profiles for assembling small-sized garden and outbuildings;
flanges are used for assembling, without welding, structures made of large cross-section profile pipes, which often have to be assembled/disassembled;
couplings are used for installation of pressure pipelines, but more often during repairs when replacing damaged areas;
When choosing fittings, you need to take into account that due to insufficient strength of the connection, it will be necessary to strengthen it by welding.

When purchasing connecting parts, be guided by the following criteria:

before starting work, sketch out a sketch, according to which they calculate how many and what elements are needed;
the wall thickness of the crabs cannot be less than 1.5 mm, since parts made of thinner metal do not provide the required strength;
there should be no cracks, chips, dents, configuration changes or dimensional deviations on the parts;
elements with a scratched surface and corrosion stains will not last long;
The service life depends on the manufacturer, so it is better to buy products from well-established companies.

The crab system is rightfully considered the best option for constructing buildings with your own hands. However, despite the ease of making connections without welding, this method is not applicable in all cases when it is necessary to assemble a structure from profile pipes. For example, a welded gate or a pipeline laid in a wall will be more reliable in operation.

Method number 1. Crab elements

Universal fasteners designed for connecting rectangular/square profile pipes. Each “crab” consists of several parts, which are bolted together during installation. The parts of the “crab” are made of 1.5 mm metal with a durable polymer or zinc coating.

There are these types of crab elements:

volumetric (designed to connect three pipes in the corners or four inside);
T-shaped (designed to connect three pipes);
X-shaped (designed to fix four pipes);
L-shaped (designed to connect two profiles).

Home craftsmen use crab systems to assemble without welding:

greenhouses, greenhouses;
racks, benches;
Summer shower;
pet cages, aviaries;
gazebos, canopies;
supports for climbing plants, lightweight fencing.

On a note! Crab systems are also used for temporary connection of parts when repairing welded structures. In general, this is a fairly reliable connection method, hardly inferior to welding in strength.

long service life (up to 50 years);
structures can be assembled/disassembled many times;
affordable cost of crab elements;
Even an unskilled worker can handle the assembly;
versatility.

pipes larger than 40x40 mm cannot be connected;
joints must be protected from corrosion, as moisture accumulates in them;
pipes can only be connected at an angle of 90 degrees;
if a large tensile load occurs, pipes may be pulled out of the crab elements;
The nuts need to be tightened regularly.

Welded joints

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Welding is a very popular method of joining individual parts in a pipeline structure. This method is especially in demand when installing technical communications in factories.

The most commonly used method for installing steel pipelines is hot welding.

It is worth noting that not only individual parts in metal structures, but also plastic products can be connected by welding. In some cases, welding is also used to join glass parts.

Depending on the method of exposure to the material, there are two main methods of such connection:

fusion welding;
pressure welding.

Fusion welding has many implementation options:

electric arc;
simple electric;
electrobeam;
laser;
gas welding.

The most popular among these options is the first one. The use of electric arc welding implies that the heating source is an electric arc. This type of work can be performed in two ways:

with alternating current;
with direct current.

Metal welding can be done with electric or gas equipment

This type of installation can be carried out using various equipment, so three types of welding can be distinguished:

manual;
semi-automatic;
automatic.

Types of welded joints

There are different methods for welding individual parts in pipeline communications. Let's look at them:

end-to-end;
overlap;
corner;
with welding of various elements.

The most popular and common are the following welding connections:

Butt (longitudinal and transverse). With this welding option, backing elements - rings - can be used. The seam in such joints can be one- or two-sided. The latter is used in cases where the part has a large cross-section - more than 500 mm.
Angular (one-sided and two-sided). This option can be done in different ways. In some cases, corner joints are welded with an edge bevel, and in others - without it.
Socket-welded overlap clutch. The socket connection is used to join pipeline elements with a high ductility coefficient. These include parts made of non-ferrous metals, as well as plastic elements.

In addition, square pipes, which are used in construction and the production of various furniture, are also connected by welding. They are not suitable for installation of pipelines. This is due to the shape of their cross-section - it worsens the flow characteristics, while round is the best option for pipeline structures.

Butt welding is used for pipes whose diameter exceeds 50 mm

Generally accepted rules for piping installation

Installation is carried out manually. The crowbar serves as a lever for positioning the pipes; a wooden spacer must be provided between them and the crowbar. If the lever cannot fulfill its purpose, professionals recommend using a jack.

Upon completion of the pipeline installation, it is necessary to check the correct placement of the sealing gasket in the socket. A thin metal plate, 0.5 to 0.8 mm thick, is inserted between the smooth end and the socket. The plate must be in contact with the rubber ring. Then it moves around the circumference of the pipe, and at the end the location of the ring in the socket is checked: the distance from the plate to it should be the same along the entire circumference.

If the pipeline is installed at sub-zero temperatures, it is necessary to carry out the work with extreme caution and use only silicone lubricant. If the pipeline is installed using the socket method in a residential (warm) room, then liquid soap can be used as a lubricant for their smooth end and socket

Threaded connections

How you can improve a well with your own hands: several different ways

But what to do in cases where it is not possible to carry out welding work? There are quite a few ways to join pipeline elements without welding. The most popular option is threaded installation. Pipe threading is done using cutting machines or an ordinary die. If it is necessary to apply threads to a product with thin walls, use the rolling method.

If you follow all the rules for installing a threaded joint, you will get a durable and sealed structure. Let's consider the main advantages of using such a connection:

ease of installation.
the ability to repair or replace without damaging the pipeline;
installation is carried out without the use of special equipment.

In addition, there are several thread parameters that determine its operation:

cutting step;
depth;
direction.

The pitch determines the distance between the top of the coil and its base. Depth is a parameter that is determined as follows: the distance between the base of the coil and its top is measured. The direction of the thread is an important point; if you ignore it, you may encounter problems when installing the pipeline structure. The thread has two directions:

right;
left.

Many types of pipes are equipped with threads; they are used where it is necessary to create a reliable but detachable connection

Final works

To ensure that a self-installed fence made from corrugated sheets has a finished look, a U-shaped strip is placed on the upper edge of the sheets. With it, the fence will be safer and prettier. Forged products installed on top of the fence increase its attractiveness and prevent intruders from climbing over the fence.

Plastic plugs are driven into the ends of the supports with light blows. To protect the pillars from moisture getting inside, decorative covers of various shapes and colors are also used. They are easy to choose in accordance with the design of the site.

A self-made metal fence will reliably protect the area from stray animals and uninvited guests. With the right color, it will fit perfectly into any landscape design, complementing or highlighting the decoration of the house. Manufacturers have mastered the production of profiled sheets with imitation of valuable wood species. You can do all the work yourself without involving specialists. All you need is desire and time.

Crab system for profile pipes

X-shaped crab bracket from RUR 28/pair

This fastener is now becoming very popular and in demand among summer residents and owners of private housing construction. What is this you ask? Let's not look far for an example

Many of you, especially those who have already purchased a greenhouse or are just looking and thinking about which one to buy, have probably noticed that more and more often manufacturers have begun to offer consumers their products using crab systems when assembling them, thereby meeting the buyer - this is of course makes me happy

The crab system is used as a fastening connection for profile pipes, while eliminating welding work, which means saving time and avoiding unnecessary expenses associated with welding work (electricity, welding machine, wires, the welder himself and his remuneration, etc.), you only need a wrench and that's it!

Crab systems are available in various combinations, it all depends on the type of node connection, shape and size of pipes, here are the most basic types:

Photo 1. X-shaped crab bracket for a 20mm profile pipe.

Photo 2. T-shaped crab bracket for 20mm profile pipe.

Photo 3. L-shaped crab bracket for a 20mm profile pipe.

The type of crab joint is already clear from the letters themselves; let's look at the shape. The shape of the pipes can be round, square or profile, the size of these pipes can also be different - this means that the combinations can also be different. When purchasing, always indicate the outside size of the pipes of your joint.

You see everything is simple and you have begun to understand all this, which means you can do everything with your own hands!

Where can you use the crab system:

when assembling a greenhouse and greenhouse
when assembling a summer shower cabin
when assembling the rack
when assembling a gazebo or canopy
when assembling a carport
when assembling a tent structure for any holiday
for minor repairs, if welding has failed, and so on.

Photo 4,5,6. Attaching guides to polycarbonate greenhouse arches using a crab system

Photo 7,8,9. Fragments of the MAF construction using the crab system. Children playground.

Please note, if necessary, all your structures can be disassembled and moved or stored with the same ease. And you will agree that this is a huge and important plus.

We tried to show you that crab systems are not only reliable, but also universal.

How many self-tapping screws are needed to mount the structure?

Fasteners are often used when assembling a metal frame under sheets of drywall. Their number depends on the design features. In the standard version, the step between the metal profiles is 60 cm, in the reinforced version - 40 cm. The number of jumpers must also be taken into account.

Let's carry out the calculation using the example of a wall measuring 3*4 meters. To increase rigidity, jumpers are used, installed at a distance of 50 cm from each other.

The distance between the profile elements is 40 cm. To install one sheet, you will need 4 elements and 6 jumpers of 40 cm each. The distance between the fasteners is 25 cm. For 1 profile you will need: 300/25+1=13 pieces. For the frame you will need 13*4=52 pieces. Per sheet of drywall: 52+6=58 pieces.

This is an approximate amount. More accurate calculations are made per 1 square meter. The quantity must be divided by the sheet area: 52/3 = 18 pieces. For the entire wall area you will need 12 square meters. meters*18=216 pieces. Consumables must be taken in reserve, so the estimated need is 250 pieces.

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Connection of plastic pipes

Most of the methods described in the section on metal pipes are also suitable for fastening plastic and PVC pipes. Polymer pipes are increasingly replacing metal pipes, so information on how to combine plastic pipes for sewerage or water supply without welding and threading is becoming increasingly relevant.

There are several ways to connect one section of plastic pipe to another. The final choice of technology should be made only after assessing all the characteristics of the pipeline, including the type of material, diameter and purpose of the system.

Into the bell

Polymer pipes are made in such a way that there is a socket on one side of the product and an end on the other. The diameter of the socket is larger than the diameter of the end just enough so that the end of one pipe fits tightly into the socket of the next one. When choosing this installation option, a rubber seal is inserted into the joint to seal the area; it is recommended to additionally treat the fastening area with sealant.

The socket connection method is popular due to its ease of assembly and the ability to work with pipes of various diameters. This method is often used to build sewer systems where high media pressure is not provided.

PVC and polypropylene pipes are connected into the socket.

Fitting

Various types of fittings are used to connect metal-plastic pipes. Depending on the design of the pipelines and the tasks at hand, compression, crimp and push fittings can be used.

The types of installation of compression and crimp fittings are practically no different from each other, the difference is that in the first case the fixation is carried out using a compression ring and nut, in the second case - a crimp ring.

Installation of push fittings is noticeably faster. The prepared pipe is inserted into the product without the help of tools, and the fitting wedge is clamped when water is supplied to the water supply system.

In addition to metal-plastic pipes, push fittings can be used to connect pipes made of cross-linked polyethylene.

Collet method

When connecting plastic pipes using this method, you will need clamping fittings and collets. The work process itself consists of 3 stages.

Place the collet on the inner cavity.
Tighten the fitting nut with an adjustable wrench.
Perform the same actions on the second pipe.

The collet method is suitable for installing metal-plastic pipelines of small diameters. Plastic pipes may not withstand the tightening of the nut and burst.

Combination with collets is suitable for pipes made of cross-linked and ordinary polyethylene, metal-plastic.

Couplings

The coupling connection involves the use of an equal coupling, 2 mounting sleeves, and a flaring tool. The work process does not take much time:

A sleeve is put on the pipe;
The end of the pipe in the sleeve is flared;
The coupling is inserted;
The sleeve slides onto the coupling;
All of the above is done with the second edge of the joint.

The use of couplings is suitable for cross-linked polyethylene pipes.

Gluing

Typically, bonding is chosen when joining rigid polymer pipes. Correctly selected glue will ensure the tightness of the joint; the only drawback is the need to wait at least 1 hour before turning on the water until the glue dries. Experts advise using Griffon brand glue.

The gluing process itself is simple. The end of the pipe is cleaned and a chamfer is made with a file. When cleaning, you need to check the tightness of the fitting of the pipe into the fittings; it should not be too loose or too tight. Then an adhesive composition is applied to the chamfer, and the pipe is inserted into the fitting.

Sometimes the term “gluing” also refers to cold welding, in which the pipe material is softened by the action of a reagent and adheres to the second part at the molecular level.

PVC pipes are most often connected using gluing. Products made from other polymers are usually glued together in the case of a one-time connection.

Recommendations for welding profile pipes

Experts recommend following the rules when performing welding work when installing structures from profile pipes to create better connections:

It is better to cut metal with a saw designed specifically for this purpose, so that the cut is smooth without grooves or protrusions. All distortions must be smoothed out before welding begins.
The metal should not be covered with scale or rust. The surface must be clean and smooth. The work is carried out using a grinding machine or metal brushes.
Before assembling individual elements, it is recommended to lay out the entire structure and check all main and auxiliary parts for compatibility and dimensions.
After completing the welding work using fasteners, the seams are allowed to cool and only then removed from their fixation.

How to weld thin pipes?

It is better to weld thin pipes with one seam at once, but most amateurs cannot do this. Beginners prefer to do spot welding first and then move on to forming the seam.

Only an inverter with a set current strength of no higher than 60 A can ensure comfortable and high-quality operation in this way.

Note! For thin pipes with a thickness of less than 2 mm, electrodes with a cross-section from 1.5 to 2 mm and class ANO-21 or MP-3S are used.

How to connect a profile pipe at right angles

First of all, the pipes must be cut correctly and the sections prepared for work. For reliability, all structural elements are fixed so that the pipes do not move under their own weight. Angles, scarves or magnetic squares are used as auxiliary devices for establishing accuracy.

The welding itself is carried out in two stages. First, a rough connection is made, the necessary linear values and the position of the vertical element are checked. After cooling, the finishing seam is made.

Electric arc method

Welding profiles using an electric arc is the most common and in demand method in modern conditions.

A special feature of this approach is the ability to use the welding machine in the most inconvenient places to work.

With its help, it is possible to weld profile blanks (pipes) of arbitrary cross-section with walls of almost any standard size. When the thickness of the pipe walls is more than 4 mm, special preparation of the edges of the welded parts is necessary.

Before welding profile pipes on your own, the operator should acquire a device of the appropriate class, as well as purchase electrodes suitable for these purposes.

The welding machine must correspond to the selected pipe welding method and the main characteristics of the products being processed.

In addition to the equipment and special tools listed above, you should stock up on a face mask and special clamps for attaching profiles (they are also called “tsulagi for pipe welding”).

Arc welding can be implemented in various ways, namely:

butt connection;
by forming a seam “overlapping” and at a certain angle;
arrangement of T-joints.

With any of the arc fusion options, preference is usually given to welding from a position that professionals call “down.” However, under certain conditions of working with welding equipment, other arrangement options are possible.

Advantages of fences without welding

Here are the main advantages of fence installation technology without welding:

Speed of installation
No need for special skills
Minimum tools (one screwdriver is enough)
Affordable price of fastening devices
Possibility to adapt the fence to all uneven terrain

Welding methods

To fuse profile square pipes made of stainless steel or steel, various techniques can be used, among which the most common are inverter and manual welding.

Based on the type of energy source used in processing metal profiles, the following welding methods are distinguished:

electric arc connection method (including inverter welding);
gas welding;
contact joint.

Of particular interest is the first of these methods, which can be considered as the main one. For welding profile pipes made of plastic materials, technologies developed specifically for products of this class are used.

When choosing a fusion method suitable for each specific case, we proceed from the cross-section of metal profiles, which vary from 10x10 to 500x400 mm.

The wide range of sizes of industrially produced pipes allows you to select very specific parameters of the welding process based on a particular current load. For the entire range of billet sections, the wall thickness of corrugated pipes can vary from 1 to 22 mm.

Electrode welding and its features

The main aspects of using arc welding are the correct current mode. The location of the seams is determined by the position of the electrodes during the welding process. In this case, it is necessary to tilt the electrode slightly towards the seam.

With constant practice, you can achieve excellent results and learn how to create one of three main types of seams:

Welding is a method of connecting parts, which makes it possible to create a structure of the most complex configuration - at any angle and inclination.

Profile pipes are often used to create frames for greenhouses, fences and other fences, gazebos, etc. All metal pipes are connected using various types of welding; when choosing, you need to take into account the wall thickness.

Arc welding

Welding profile pipes in this way is considered the most convenient and therefore in demand. A special feature of electric arc welding is the ability to operate the welding machine and electrode in hard-to-reach places.

To perform the work you will need a welding machine and electrodes. Equipment can be rented from a specialized store or factory. In addition to tools and electrodes, it is worth stocking up on protective clothing (including a mask) and special fasteners for profiles.

Arc welding can be performed using various methods:

Butt connection;
Lapped seam;
T-joint;
Seam at a convenient angle.

Choosing electrodes for arc welding

Those who do not know how to weld a profile pipe should understand that the quality of the weld depends entirely on the correct choice of electrode. It is worth remembering that the cross-section of the electrode plays an important role in welding tubes of one diameter or another. Thus, an electrode that is too thin will interrupt combustion, and an electrode with a large cross-section can burn through a thin-walled pipe.

The diameter of the electrode depends on the thickness of the pipe walls:

For a tube with a cross-section of up to 2 mm - an electrode with a diameter of 1.5 mm;
For a tube with a cross section of 2-3 mm - a 2 mm electrode;
Pipes with a cross section of 4-6 mm - electrode 4 mm thick.

It is worth knowing that electrodes can be melting or non-melting. With the latter, it is necessary to use special additives made from alloys of tin, brass and other soft metals with phosphate impurities.

We perform arc welding

Welding of profile tubes is carried out in a special room. It is first necessary to clean and degrease the ends of the pipes to be welded. If the thickness of the tube walls exceeds 4 mm, then you need to prepare the edge using a chamfer. This edge will allow you to form a seam in several layers, which will make the joint stronger and more reliable.

The parts are fixed on a special table.
If the cross-section of the pipes is more than 10x10 mm, then it is recommended to apply spot tacks in several places and only after that weld the pipes.
Welding is performed at a speed that allows the metal to melt, but does not allow it to flow into the internal lumen of the pipes. In this case, the electrode can be moved in a herringbone pattern or from left to right and from right to left.

Gas welding

Do-it-yourself connection of profile pipes using gas welding is very different from electric welding. The preparatory work for the process is similar. Only all surfaces for joining are coated with flux powder. And prepare the filler wire.

Compound. This is done in two ways:

Thin-walled products are connected from right to left.
If the walls are over 5 mm - from left to right.

When working, you constantly need to monitor the position of parts. When the pipes cool, the seam is cleaned with abrasive and an anti-corrosion coating is applied to it.

Top 2 mistakes when welding profile pipes. The solution is here!!!

Watch this video on YouTube

Do-it-yourself pipe connection without welding

Small-sized frame structures are assembled without welding. In this case, the profile pipe is connected without welding using a special device.

Crab systems

They are devices in the form of a special clamp in the shape of a crab, which is placed in a specific place and connects a certain section of the profile. This device consists of two parts, they are connected with nuts and bolts.

When assembled, such a device forms a rectangular or square shape; its dimensions allow it to tightly grip the pipe product from all sides.

The most popular clamps with a size of 95x95 mm. They make it possible to make reliable connections and guarantee high-quality and durable fastening of structures.

These devices are made from galvanized or powder-coated metal.

Benefits of using a crab system

They make it possible to assemble or disassemble a structure in a short time. All pipelines with such connections become collapsible.

Fastening profile pipes without welding using crab systems is very popular. With such connections, the structure can not only be quickly moved, but also something new can be constructed.

Also among the advantages of these fasteners is the fact that the structure can be erected with small financial investments.

However, the disadvantage is that it can be used to fasten small-sized pipes.

Clamps

Used for a profile to a fence building. The device has a rectangular shape and is made up of two parts. One of them is screwed into the wall and a pipe is inserted there. The second part of the pipe is fixed (with a clamp and bolts).

Fitting

Another way to connect profile pipes without welding is with fittings. They are used in situations where you need to make branches and bends. They are a fixed fastener for the joint and end. These fasteners can be of the following types:

Tees and crosses. They are used for branching, and they connect products of different and the same size.
Squares. They are used when it is necessary to change the direction of a pipeline.
Couplings. They are placed at the docking point.

Now you know how to weld a profile pipe, and video lessons will help give a visual representation. We also looked at what connection methods exist. Using this information, you will get the job done easily and quickly.

Method number 4. Flanges

Such fasteners consist of a pair of rectangular or round metal plates with holes for bolts and pipes. The assembly algorithm looks like this:

the ends of the pipes must be cut perpendicular to the axis;
burrs should be removed and then the flanges should be put on;
a rubber gasket is installed between them, and care must be taken that its outer edge extends evenly by 8-10 mm;
at the end the flanges need to be fastened with bolts and nuts.

To make the connection durable and reliable, you need to follow a few simple rules during assembly.

There should be one gasket, no more, otherwise the tightness will decrease. The condition of the gasket should be checked every one to two years. It is better to tighten the nuts in diametrically located pairs - this will also increase the tightness. It is important that the gasket does not touch the bolts. If a water supply is being assembled, the gaskets should be made of cardboard, impregnated with drying oil. The thread of the bolt should not extend beyond the nut by more than ½ of its length. Asbestos cardboard is used to seal joints in heating systems.

How to connect profile pipes: without welding and threading

For those who have at least once changed the pipes of the water supply system, the most reliable and fastest connection method is welding. But the welding process differs greatly from the process of welding pipeline elements consisting of plastic. The main materials, in the latter case, are fittings and couplings.

What is the advantage of profile pipes?

Firstly, metal pipes of various profiles are quite resistant to damage. In addition, the pricing policy for their cost is very acceptable, and such properties as strength and reliability are attracting more and more attention.
Secondly, compared to other types of pipes, they are quite light. But this does not mean that they are only suitable for certain jobs. With their help you can make any design.

Today the market offers a lot of varieties of profile pipes, as well as their sections. Each type is selected individually.

Varieties of the welding process

Working conditions, types of connectors and pipe material are the determining criteria for its varieties.

The welding process occurs using:

gas apparatus;
hands;
electric current;
metal electrodes;
inert gases;
flux-cored wire.

By the way, in addition to the above types, welding using flux-cored wire is in great demand.

What welding process is suitable for profile pipes?

First, we need to say that in order to weld profile pipes, you need to determine the correct type of welding. Welding using inert gas, suitable for profile pipes made of steel that does not rust. Short-arc welding is used if the steel thickness exceeds 0.8 mm. If the thickness varies up to 3 mm, then it is better to make the connection by arc welding. When the thickness of a steel product is 3 mm or more, you need to choose electrodes that melt. In most cases, this type is used for industrial purposes.

Naturally, after completing the welding process, it is imperative to check the level of quality of the work done. Based on external signs, you need to evaluate the welded pipe and make sure there are no defective elements.

Types of electrodes

Regarding profile products, they are divided into those that melt and those that do not melt. Such electrodes are used depending on the material from which the pipes are made.

Electrodes that have the property of not melting require the presence of a special wire. Using them, you can connect two different pipes with the same diameter dimensions into one. During the welding process, the coating of the profile products becomes smooth. When melted, the pipe and the connecting unit merge into one product. This type of welding is quite labor-intensive, since it is necessary not to lose the properties of the material, but to achieve their preservation in their original form. It is recommended to first ensure that the edges become smooth, which will ensure that the ends are perpendicular. You need to navigate by the type of chips.

It should be noted that there are electrodes for working with cast iron and copper products. If we compare the strength of welding works of metal products and plastic ones, then preference cannot be given to anyone. In terms of the functions that welded metal and plastic products must perform, they are no different.

Why give preference to welding work?

1. Firstly, connection work is carried out using highly technical and high-quality equipment in the arsenal. This fact provides a guarantee that there will be no leaks in the future.

2. Secondly, this process will not take much time and effort.

3. Thirdly, the cost of installation work is affordable.

4. Fourthly, the joints do not affect quality and functionality. In addition, joints during welding work reach minimum values.

Do not be afraid of welding work in the apartment. This process is quite simple and reliable. It is not necessary to use the services of professional welders; two people can handle this work, one of whom will be an assistant. The main thing is to adhere to the requirements of the job and do everything right.

Gas welding of pipes

Experts less often connect pipes using gas welding, preferring to use electric arc welding. The reason is that the use of a gas welding machine increases the cost of work, is more dangerous due to acetylene, and requires thorough training of a specialist. However, gas installations are also used in such work. And this is due, first of all, to the inability to connect to the power supply network.

In practice, there are two methods for using gas welding equipment:

The welder moves the filler material following the torch from left to right. This technology is usually called “right”. The advantages of the method are excellent heating of the materials being joined and excellent visibility of the working area. As a result, gas consumption is reduced and the worker’s productivity increases. However, this method of operation is acceptable for pipes with a wall thickness of 5 millimeters or more.
The “left” method is characterized by the fact that the filler material moves in front of the burner in the direction from right to left. It is in demand when working with thin-walled pipes.

It is customary to distinguish several stages of welding profile pipes using a gas torch. Initially you will need to purchase materials:

oxygen and acetylene cylinders;
filler material;
gearbox;
gas burner with tips;
flux;
gas supply hoses.

It is necessary to pay attention to the fact that the gas installation is unsuitable for use when it is necessary to weld a thin-walled profile pipe. The metal will melt too quickly and the tightness of the joint will be questionable

At the first stage, you need to prepare the surface: degrease and clean from foreign matter. The workpieces are firmly fixed on the work table. The edges are treated with a paste-like flux, which prevents oxidation of the metal during the welding process. Experienced welders recommend making bevels on the edges of pipes at an angle of 30 degrees. This will allow you to make several high quality welds.

The flame is formed as a result of the combustion of a mixture of oxygen and acetylene. The filler material is supplied to the joint and moves ahead of the burner flame. The burner temperature is sufficient to melt both the additive and the metal of the workpiece. As a result, the melts combine to form a weld. The burner should be moved from right to left. The opposite direction is used when the walls of the pipelines are thick. In this case, the wire is fed after the torch, and not in front of it

It is very important for high-quality welding to choose the optimal electrode diameter

During operation, it is necessary to control the geometry of the structure. Due to the high temperature of the burner, it is easy to make a mistake and heat one side more than the other. This may disrupt the symmetry of the workpiece arrangement. Therefore, you need to carefully monitor this and correct the situation if necessary.

Source

How to connect pipes without welding or threading

Couplings and press fittings

A compression coupling connects two well-aligned sections of pipeline, in which a slotted conical bushing is installed above the joint, and two flanges are stretched above the bushing, so that they automatically center the pipes and provide sufficient contact pressure.

Collet method

Suitable for joining areas with a small embedment depth, but not possible if adjacent elements are plastic. For connection, a standard insert is used, which is located around the areas to be connected and then crimped. Reliable grip is ensured after at least two full revolutions of the collet. Not recommended for stainless steel pipes. The most famous system of this type is Speedfit clamps.

Crimping fittings

How to connect a metal pipe to a plastic pipe without threading or welding? It is the crimp fittings that will be effective. It includes two tubular parts, one of which extends from an adjacent section and has an increased length. The products do not have an internal stop, and therefore are easily inserted into hard-to-reach places. The joint is crimped using press pliers, the versatility of which is supported by replaceable inserts. Because there is no alignment stop, the installer must carefully measure the final position of the fitting to ensure it is positioned correctly.

Crab systems for profile pipes

The principle of operation is similar to crimp couplings, but they are mainly used when connecting heating and air conditioning systems, characterized by the characteristic appearance of the clamp. There are systems with the following configuration:

Universal, for corner connection of three or four pipes;
T- or X-shaped, the cross-section of the staples corresponds to the outer size;
For joining at any angle.

Gebo couplings

For installation you need to make several transitions:

Prepare the joint for installation of the element (sand the joints, remove possible burrs);
Disassemble the coupling;
Place the components in the following order: clamp, tightening ring, seal. The free area must be no shorter than 12...15 mm;
Install the Gebo coupling on the prepared area, then tighten the nut;
Perform the same operations with the adjacent tubular part.

Repair and installation clips

They are made in the form of cast coupling halves, with an internal diameter corresponding to the external size of the pipe. Inside there is a sealing element, the material of which must correspond to the operating conditions of the joint. After installation on the area to be connected, the halves of the cage are evenly tightened with bolts. Here, the perpendicularity of the end elements is of particular importance, since this method does not protect against tangential displacement.

Application of clamps

Connecting steel pipes with clamps is used primarily for unsealed tubular joints, which are typical for tubular railings, fences, etc. As the width of the clamp increases, the reliability of holding parts increases. It is better to use universal clamps.

DIY installation of profile structures

In a unified form, the assembly instructions can be presented as follows:

Development of a product drawing, where dimensions, bend angles, fastening methods, pipe sizes, etc. will be specified in detail. As for the dimensions, they are determined based on the main purpose of the structure. For massive structures (gates, house frames or outbuildings), it is better to take pipes with dimensions of 100x50, 80x80 or 80x60 mm. Products with a cross section of 50x50 or 40x60 are ideally suited for the construction of display cases, shelving, and scaffolding. For furniture items, thin-walled profile pipes measuring 40x25 or 20x20 mm will be sufficient.
Applying markings, cutting pipes and preparing individual structural elements. It is more convenient to cut a thick-walled dimensional pipe with a grinder, while for small products it is better to prefer an electric jigsaw or a hacksaw.
Cleaning the cut areas is done with a flat file or with the same grinder with a metal disc or emery wheel.
Connection of elements. It can be done by welding (it will save time, but will lose in aesthetics) or by bolting. In the latter case, you will need to drill a large number of holes using an electric drill. With profile pipes, unlike round pipes, due to the flat cross-sectional configuration, the area of contacting adjacent elements is sufficient to ensure a reliable connection.
Installation of fittings (hinges, bolts, latches, handles, etc.), as well as covering surfaces with suitable materials. It can be polycarbonate, metal, solid wood or plastic.
Final cleaning and painting of the finished product. This stage of work will help protect the joints from corrosion, and give the structure itself an attractive appearance.

Features of metal profile bending

Many products (especially pieces of furniture) that you can make yourself from a profile pipe will look stylish and elegant with rounded elements. This inevitably brings the home craftsman to the issue of bending pipes.

It will most likely not be possible to do this manually; the bend will almost certainly be uneven, or even lead to a break in the pipe. There are several ways to correctly bend a profile pipe:

Order the necessary operations to be performed at a factory that has the necessary professional equipment. Not the most convenient method, requiring delivery and removal of products from the factory, which may not always be found nearby.
Buy your own pipe bender. The device is easy to find on sale in large construction stores, but it is quite expensive, so the purchase will be justified only for constant large volumes of work. The most suitable option for those craftsmen who have turned the production of structures from profile pipes into a permanent business.
Use an angle grinder and a welding machine. Not the most aesthetic method, which involves making several (the number will depend on the required bending radius) slits, bending the pipe and welding the seams.
Bend the metal profile using sand. A wooden plug is tightly driven into one end of the pipe, after which the product is filled with sand and closed in the same way from the second edge. After these manipulations, the bend turns out smooth and aesthetic, and the sand, after giving the desired configuration, is simply poured out. In the cold season, sand can be replaced with water frozen in the cold.

Types and advantages of fittings

Why is it worth using fittings and what is the main advantage of this material? The answer is simple: these elements have a simple design, but are practical, they have a long service life and an affordable cost. Without using welding equipment or expensive taps and lerks, the user achieves the same high results using simpler fittings.

Fitting

Fittings are successfully used not only for the installation or repair of pipes; this material is also popular in the manufacture of compression equipment and gas turbine mechanisms. This means that the product creates sufficient tightness with the help of a seal, even in systems with high pressure.

Types of fittings by size and application:

Direct. This means that the diameter of the product remains unchanged on both one side and the other. Used to connect two identical pipes.
Adapter fittings. Necessary for connecting two pipes of different diameters. Indispensable, for example, when repairing an old pipeline, where a large number of pipes have different sizes.
Tees. Allows you to make a branch from the main line without threading or welding.
Crosses. They have the same purpose as tees, but are capable of dividing the main line into a larger number of branches.
Fittings. Used as a connection for flexible metal pipes. The fittings are able to create sufficient tightness even when connecting a material that changes its structure.
Pipe plugs. The main function is to block the end of the pipes.

It should be clarified that the variety of fittings, as well as their manufacturers, allows you to purchase products both for installation outdoors and in an apartment or private house.

Advantages of X-brackets

Fastenings for mounting a fence made of corrugated sheets are different, but the most convenient is a cross-shaped bracket. With the help of the X-bracket, installation of fence sections is easy and without the use of welding.

The installation principle is simple: attach the sections to the supporting posts with metal screws.

To install corrugated fencing with your own hands, it is enough to have the following tools and materials in your arsenal:

X-brackets - special cross-shaped fasteners;
consumables (nuts, washers, metal screws);
metal corners or channels on which the sections will be attached;
screwdriver;
roulette;
a set of keys.

The advantages of using an X-bracket for mounting are obvious:

minimal set of tools;
there is no need to use welding;
strength and reliability of fastenings;
high speed of installation work;
it is possible to level the overall structure of the fence by tightening the fastenings;
low cost.

The frame installation process is as follows:

Mark the places for fastening the transverse pipes (angles) on the load-bearing supports. To do this, use a tape measure to measure 0.2 m from the top of each post, and 0.3 m from the bottom.
Attach the X-bracket to the support and screw the self-tapping screw through the front hole. Do the same with all the pillars. For supports at the corners of the perimeter, use corner brackets; for gates and gates, use end brackets.
Now hang metal crossbars on top and bottom of the post mounts. Each crossbar must fit exactly into the mounting groove on 2 supports standing next to each other.
Next, mount the next span in such a way that the crossbar from the first element is connected through the X-bracket to the previous one. At the joints, fix the crossbars with a T-shaped profile using self-tapping screws. In this way, connect all the crossbars sequentially along the entire perimeter of the future fence.

After the frame is mounted, you can begin covering the fence with corrugated sheets. This is the final stage of fence installation. You can't do it alone, so you need to get someone to help. The plating process looks like this. Press the sheet of corrugated sheet tightly against two load-bearing supports horizontally and fix them to them and the crossbars using a screwdriver and self-tapping screws. In this case, one person holds and presses the sheet tightly, and the second is engaged in fastening.