Installation of pipelines for water supply and heating networks is usually carried out by welding, less often - using threaded connections. By doing repair work usually the same technologies are used.
Situations often arise when the use of welding or threaded connections is difficult for some reason. For example, in an apartment it is necessary to repair the heating or water supply pipework, which runs close to the wall or to another pipe.
It is impossible to perform a circular welding of the joint of such a pipe or to cut a thread on it. In this case, the acute problem arises of how to connect pipes without welding and threading. And there is a solution to this problem.
Connection without welding or threading is possible thanks to special parts - fittings. A fitting (from English “to mount”) is an element used in the following cases:
Mounting parts designed to perform various functions, have their own names. To connect pipelines of the same diameter, couplings are used; pipes of different diameters are connected by adapters.
To turn the pipeline route, bends having the required angle are used. A double branch in a perpendicular direction is made using a tee, and there are also crosses, fittings, plugs, and manifolds.
Fittings can be threaded or crimped. Since we are talking about pipe connections without welding and threading, the subject of consideration will be the relatively recently appeared compression fittings, otherwise called compression fittings.
Compression fittings for pipe systems
The technology for using crimp parts, which allows connecting metal pipes without welding or threading, has appeared relatively recently.
A pioneer in the production of fittings for pipe connections without threads and crimp welding was Gebo Armaturen GmbH, which received the first patent for this technology back in 1937.
Today the name of the company has become a household name; the fittings for crimping pipe connections are called “Gebo coupling”.
In the production of connecting fittings, Gebo Armaturen uses ductile cast iron. The company's product range includes fittings for various types connections and branches.
Gebo fittings are designed to work with pipelines made of different materials. With their help you can connect plastic pipes, pipe products made of steel, copper, aluminum. There is no need to use welding or threading.
Repair and installation clip
A universal product that can be used to repair pipe metal products without welding, as well as polyethylene pipes, is a repair and installation clip.
It consists of two cast cages in the form of semi-bushings, having four ears for bolt fastening. Included in the package rubber seal in the form of a hose cut to length and four bolts.
In essence, it is a clamp that plumbers often use, but it is made very well. Available for pipes of different diameters, making it possible to repair them without welding or threading.
The product is used for repairing damaged pipelines for various purposes. If it occurs in a pipe through hole, a split seal is placed on the damaged area, with the cut oriented in the direction opposite to the damage.
Clips are installed on top of the seal and the bolts are tightened. These repairs do not require welding and can sometimes be done under pressure without shutting down the pipeline.
Repair and installation clip with outlet
This product differs from the previous one in the presence of an outlet with an internal thread on one of the cast-iron holders.
The seal in this fitting also has the shape of a cut hose, but on the side opposite the cut there is a hole, which should be aligned with the outlet during installation.
This fitting makes it easy to make a branch from the pipeline; just drill a hole in its wall. Can be used when installing watering lines. Taps or water sprayers can be screwed directly into the threaded elbows.
Double-sided crimp connections
A universal product with which you can connect steel pipes, as well as PVC pipes. It is this fitting that is most often called the Gebo coupling. It can be used to connect two pipes end to end.
To make a connection, the pipes must be cut evenly and cleaned of dirt and rust, the ends of the pipes must be well processed. A clamping nut is put on the end of the pipe, then a clamping washer, which is a collet - a conical bushing with a cut on one side.
The inner side of the bushing is covered with circular notches. A sealing gasket is inserted into the coupling seat, designed to stop the end of the pipe. After this, the clamping nut is tightened.
Moving along the thread, the hole in the nut presses the conical part of the split sleeve against the pipe. At the same time, the internal notches of the sleeve cut into the surface of the pipe, tightly fixing it and pressing it against the end gasket. This way ensures the necessary tightness and mechanical strength of the connection.
A similar procedure is performed on the second side of the coupling, where the end of the second pipe is inserted.
Single and double clamp and thread connections
A fitting with a one-way clamp is like half of the coupling described above. On one side the pipeline is connected, the other side is a branch with internal or external thread.
Where a tap or outlet can be screwed into. It is, in fact, a tee. The double clamp connection can be used to quickly install a perpendicular pipe bend without welding.
For the installation and repair of heating and hot water supply pipes, the company produces a full set of fittings equipped with elastic gaskets capable of operating at a temperature of +95°C.
All these fittings, like those described above, are universal and can be used to connect polypropylene pipes.
Gebo's range of fittings includes connecting devices for large-diameter main pipelines intended for underground installation. The connection of pipes in such pipelines can also be carried out without welding and threading.
Flange Applications
A flange connection is used in cases where it needs to be disassembled at some intervals. To make such a connection, flanges must be installed at the ends of the pipes - round plates with holes for bolts.
The flanges must be secured by welding. For subsequent assembly and disassembly, the connections will only be needed spanners for tightening bolt threads.
When installing a flange interface, an elastic gasket is placed between them, after which the flanges are pressed against each other and clamped with a bolt thread.
In water supply and heating systems, flange mountings often have metering devices and circulation pumps, which must be removed every season for prevention, repair and verification. Flanges can be used during installation summer water pipelines, which must be dismantled every autumn.
Fastening professional pipes
Profile pipes used for the manufacture of load-bearing structures are most often connected by welding. In the event that such a pipe structure must be collapsible, it is necessary to make a connection profile pipes no welding. For this purpose, various fasteners and clamps.
The so-called crab systems, which are stamped from sheet metal curly braces.
Crab systems allow various options joints of two, three and four profile pipes in different planes.
The angles formed by the pipes connected by such a system are always 90°. Using crab systems, it is convenient to assemble temporary structures from profile pipe elements, for example, scaffolding. The system is tightened using the threads of bolted connections.
For a metal pipeline, only a high-quality and reliable connection is necessary. Insufficient tightness of the system leads to low pressure in it, and, accordingly, to some inconveniences. Many owners of private houses and apartments know only the most popular connection methods: using a weld or thread. Of course, these methods are the most practical, especially if you have at hand necessary tool. But there are other options for how you can connect metal pipes to each other.
Before moving on to the immediate topic, you should consider popular methods of connecting metal or steel pipes. These include:
- Compound metal pipes by welding. It is used most often, but has a number of negative aspects:
- High price. Welding equipment is quite expensive, and its use accounts for half the cost of a welder.
- High complexity of application. Not always, but quite often the welder is faced with a problem in which he simply cannot use welding. For example, in a cramped room or at a high altitude.
- Insufficient execution speed welding work. Transportation and preparation of equipment takes a lot of time, so you often have to wait a long time for a welder.
Pipe welding
- Coupling connection. Couplings for pipes (especially large diameters) are expensive and are often used to eliminate emergency situations. More practical option is the installation of fittings, which will be discussed below.
Types of pipe connections without welding and threading
But if you don’t have welding equipment or a set of taps and drawers at hand, then you should use the following methods:
- Use pipe fittings. Affordable pricing and good quality make these products the most acceptable. The fittings have a rigid structure, which is why they tightly and reliably grip the pipe section, preventing the passage of liquid circulating through the system. The service life of a fitting depends on its manufacturer, so it is best to give preference to products from Switzerland or France.
- Use flanges. The design of the flange resembles a standard clamp, along the inside of which there is a rubber compressor. The flange has the following advantages: ease of installation, low cost, durability.
- Apply Gebo coupling. The design of the Gebo coupling is quite simple and consists of three rings (clamping, pressing and sealing), a nut and the flange itself. Installation of this product will not take much time if you know the exact installation sequence. By using the Gebo coupling, you can achieve high tightness of the connection. The service life of the product is long, with the exception of the sealing ring, which has to be changed at certain time intervals.
- Apply the repair and mounting clip. Structurally, this product is made in the form of two parts that must be tightened using bolts. It should be remembered that the repair and installation clip belongs to the category Supplies, used in emergency situations. It should not be used for long-term use.
The above connection methods are suitable for pipes with a rigid structure. These can be products made of metal, steel, cast iron or polyvinyl chloride. For profile products that do not require high tightness, the following connection options should be used:
- Clamps for fastening. Universal elements used in almost any construction industry. Using clamps, you can tighten 2 or more profile pipes, and the design, in terms of strength, will not differ too much from a welded one.
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. Not using welding equipment or expensive lever taps, the user achieves the same high results using simpler fittings.
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 able to divide the main line into large quantity 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 for installation on outdoors, and in an apartment or private house.
What is a Gebo coupling?
Gebo coupling - appearance
A Gebo coupling is a one-way coupling that has elements such as compression rings and a threaded connection. The Gebo double-sided coupling has compression rings located on both sides.
Gebo coupling design
The design of the Gebo coupling implies the presence of a special recess for a rubber seal, which creates a tight connection. The seal is made in the shape of a cone, which facilitates its penetration even into the most inaccessible cracks when tightening the coupling.
Procedure for using the Gebo coupling
In order for the operational life of this product to be as long as possible, it is necessary to know the correct installation process, which will maintain the required tightness of the connection of metal pipes.
- Both pipes should be cut as evenly as possible and its edges should be cleaned, getting rid of small metal burrs. Paint or enamel is also removed, right down to the metal. To do this, you can use fine sandpaper or a special grinder wheel.
- The first thing to put on the pipe is the nut that comes with the coupling. Next, you need to place a cone-shaped ring on the pipe so that top part cone looked at the nut.
- The second thing to put on is the pressure ring, followed by the seal. The seal should be turned towards the fitting.
- Next, you should tighten the fitting so that when you tighten the nut, it does not turn. Tighten the nut so that 1-2 threads remain.
The coupling is installed and you should check its quality by supplying water to the system. If drops of liquid appear from under the coupling, it is necessary to tighten the nut slightly and recheck the connection for leaks. At reappearance moisture, the coupling should be removed and the area underneath it cleaned again.
The main advantages of the Gebo coupling
Gebo couplings are often used due to the practical ratio pricing policy and product quality. At correct installation, the coupling can last long years, after which it is enough to replace the rubber O-ring on it and it can be re-installed on the pipeline.
The breadth of application of this product is also appreciated. Like ordinary fittings, the Gebo coupling is used not only in water supply systems, but also in compression systems. To complete the connection it will take a minimum of time, and it does not require the presence of special tools.
Using repair and mounting clips
Repair and installation clip
An easy to use pipe design that is also quite durable and requires no threading or welding. The repair and installation clip consists of two metal parts, a seal and 4 tightening bolts. Unfortunately, it is not recommended to use the clip for a long period of time - this type of fitting is designed to quickly eliminate emergency situations.
Installing the clip (along with stripping) will not take much time. But the connection must be made carefully, and after installation it is necessary to check its quality.
Sequence of use of the repair and installation clip
- The clip can easily be used to close, for example, a crack in a pipeline without threading or welding. It is not suitable for connecting two pipes. Therefore, after detecting a crack, the area around it should be thoroughly cleaned using fine sandpaper. After cleaning, a clean and smooth surface should be formed on which the seal will fit tightly.
- Next, put a rubber pipe seal over the damaged area so as to completely cover it. The slightest gap will lead to fluid leakage.
- Now the two halves of the repair and installation clip should be put on the seal and tightened with four bolts. There is no need to tighten too much to avoid damaging the threads.
- Let in the liquid and check if the connection is tight enough. If necessary, tighten bolts or nuts.
The simplicity of this method makes it very popular. Second positive quality– the repair and installation clip has a low cost.
Flange connection – convenient installation and affordable price
A flange connection is used even when it is necessary to join a plastic and metal pipe without threading or welding. This connection of metal pipes without welding is made using bolts and has high strength and tightness.
The design of the flange for the pipeline is simple: 2 metal disks, each of which fits a pipe. There is a rubber seal between the discs. To connect the structure, there are bolts on which nuts are placed on the other side.
This connection of steel pipes is reliable and durable and can be used for several decades. But after certain time intervals (1-3 years), the flange must be carried out Maintenance connections and check the quality of the seal.
If you are interested in how to connect two aluminum pipes, we will tell you about the intricacies of this matter and reveal it small tricks. The need for this operation appears quite often in everyday life and sometimes very experienced craftsmen can be confusing. Typically, this task is performed using welding or threading. But there are other ways. After all, welding work is not only expensive, it requires professional equipment and a specialist and cannot always be performed in the right place. In addition, sometimes pipes need to be connected very quickly, without waiting for the welder to arrive with the equipment.
Fittings can do anything
To quickly and reliably connect aluminum pipes at home, special fastening elements - fittings - have been created.
They are divided into two types:
- along the cross-section of the elements to be connected: straight (two identical diameters) and transitional (two different diameters),
- by purpose: corners and bends, tees, couplings, crosses, fittings, adapters, plugs, caps.
Fittings not only productively solve the problem of how to connect aluminum pipes without welding, but also simplify the process of installing any communication networks or manufacturing various structures.
The most popular fittings are the crimp type of installation, or more precisely, press fittings.
Why are compression fittings recommended:
- the joining of pipes is completely sealed,
- strength and reliability of the connection,
- vibration resistance.
Types of fittings
Couplings are the most commonly used type of fitting elements. High-quality couplings with fasteners allow you to quickly and reliably ensure reliable joining of two or more pipes. A variation of it called the Gebo coupling is also often used.
Flanges with rubber gaskets ensure reliable joining of pipes. It is preferable to select such elements with a large cross-section.
Also, the question of how to connect an aluminum pipe to each other can be answered by a device such as a repair and installation clip. This is a coupling or triple type of fitting, consisting of 2 parts attached to each other. This is very good way for an express option for joining pipes - for example, in case of an accident or other emergency situation.
No less effective and simple is the method of joining pipes using a clamp, which ensures a reliable connection. It tightens on one side, which makes it different from a clip. The connection is therefore considered more durable.
How to Join Square Aluminum Tubes
Aluminum pipes of square, rectangular or other cross-sections are usually connected using a crab system or clamps.
The crab system is narrow strips of metal made of 2 parts connected to each other. They have the shape of the letters T, X or G and can securely cover pipe sections. The resulting joints are highly reliable. But the joining occurs only at right angles and is made for pipes small size sections.
More universal method The joining of pipes with a complex profile is a clamp. We offer to select and buy aluminum pipes on our website at competitive prices and in a wide selection.
17330 0 7
Size matters: how to connect two pipes of the same diameter
In this article I want to talk about methods of connecting pipes, first of all - hermetically sealed ones, used in the installation of water supply and sewerage systems. The material is of a review nature and is intended only to acquaint the reader with a variety of installation methods: I will deliberately not mention the subtleties of technology and recommend this or that tool. So, let's go.
Steel
Despite the abundance polymer pipes, black and galvanized steel still remain in demand in the housing and communal services sector and for the installation of highways high pressure. The methods used for connecting elements of steel pipelines largely depend on the cross-section of the pipe.
Electric welding
Diameters: any, pipe wall thickness: from 0.5 mm.
When welding with high currents, it is easy to burn through the walls of a thin-walled pipe; a decrease in current leads to sticking of the electrode. Therefore, electric welding of thin metal requires a certain skill.
Dignity: arc welding- the only way to connect large-diameter pipes with significant wall thickness, ensuring acceptable weld strength. Automated welding is used in the production of seam pipes and in the installation of pipelines.
Disadvantage: a sealed seam is almost impossible for a beginner. Pipeline welding requires the highest qualifications.
Technology:
As usual, there are a number of nuances:
- The chamfer can be removed only from the outside of the pipe or from the outside and from the inside. Thick-walled pipes of large diameters are welded on both sides;
- When welding pipes of small diameters, the braids must first be grabbed at two or three points and aligned along a common axis, then begin welding the seam along the entire circumference. Because of uneven heating the seam area leads noticeably;
- Welding can be performed with a continuous supply of argon to the arc area. Inert gas completely eliminates oxidation of the seam.
Minor leaks in cold water supply lines can be eliminated by rubbing hot seam a piece of bitumen. Thanks to the capillary effect, it instantly fills the pores with melt. This instruction is useless in hot water: when reheated, the bitumen will melt again and be forced out of the pores.
Gas welding
Diameters: up to 100 - 150 mm.
Pipe wall thickness: up to 3-4 mm.
Advantage: undemanding welder experience. I was able to achieve a sealed seam after just a few hours of practice.
Disadvantage: inability to cook thick-walled pipes with gas. The burner is simply unable to heat their walls until the edges melt.
Technology:
- The pipe is cut perpendicular to the longitudinal axis;
- The outer chamfer is removed from thick-walled pipes (more than 2 mm);
- The edges of the future seam are heated with an acetylene torch until they glow bright red and melting edges;
- A welding wire is inserted into the torch flame, the melt of which fills the seam. The melt bath should not freeze: only in this case will the seam be airtight.
A special case
Fixed seams are welded with a mirror or using surgical suture. In the latter case, a window is cut in the pipe, then the seam is welded from the inside, after which the window is welded again.
coupling
Diameters: up to 50 mm.
Wall thickness: any.
Advantage: the simplest threaded connection of pipes that can be connected in series and rotate around the longitudinal axis.
Disadvantage: the coupling assembly of a long string eliminates the disassembly of a separate connection. The pipes have to be unscrewed from the couplings sequentially.
Technology:
- The pipes end at right angles to the longitudinal axis;
- On lathe or with your own hands, using a die, cut a short (five threads) thread on both pipes being connected;
- A threaded pipe is screwed onto one of the pipes, into which the second pipe is screwed. For sealing, plumbing flax is used (preferably impregnated with paint or sealant) or polymer sealing thread.
Couplings, in particular, were installed in houses with steel water supply connections and served to connect them with eccentrics when installing a wall-mounted mixer.
Sgon
Diameters: up to 50 mm.
Wall thickness: any.
Advantage: makes the connection of fixed pipes dismountable.
Flaw: long threads of the drive are most vulnerable to corrosion thanks to minimum thickness walls and lack of protective paint coating. Once applied, it is broken upon the first disassembly.
Technology:
- A short thread (5 threads) is cut on one pipe, a long thread (12-15 threads) is cut on the other;
- A locknut and coupling are screwed sequentially onto a long thread;
- The coupling is pushed all the way onto the wound short thread;
- Following it, a lock nut is driven in, clamping the thread winding in front of the coupling.
Flanges
Diameter: 76 mm or more.
Wall thickness: from 3 mm.
Advantages:
- The connection remains collapsible, including on non-rotating lashes;
- The force required for installation or dismantling is not tied to the diameter of the pipe. As the diameter increases, the number of bolts holding the flanges increases;
- Flanges can be used to connect to shut-off valves or to install retaining washers. In particular, it is the washers that ensure circulation in the hot water risers of most houses built in the 80s and newer.
Disadvantages: flange installation is carried out only by electric welding, which is not always convenient in field conditions.
Technology:
- The pipes end perpendicular to the longitudinal axis;
- The outer ones are removed from them (and when large diameter- and internal) chamfers;
- The flanges are welded;
- After cooling and cleaning the seam, the flanges are tightened through a rubber, silicone or paronite gasket. The bolts are tightened alternately, crosswise, one turn at a time. The price of breaking this simple rule is uneven compression of the gasket and a high probability of leaks during pressure surges.
Compression fittings
Diameters: up to 32 mm.
Wall thickness: any.
Advantages: extremely simple installation using under hand tools, possibility of installation on corroded pipes.
Disadvantage: low tensile strength of the connection.
Technology:
- The edges of the pipes are cleaned of paint and rust;
- They are then inserted into the fitting with the nuts loosened;
- The nuts are tightened. At the same time, they compress the pipe with rubber O-rings, sealing the connection.
A special case
Compression fittings are also used for installation corrugated pipes made of stainless steel. However, in this case, the strength of the connection is not inferior to the strength of the pipe itself: it can withstand pressure up to 50-65 atmospheres. The secret is simple: the silicone seal of the fitting does not compress the smooth surface, but the crest of the corrugation, so it is almost impossible to tear it out of the tightened fitting.
Many fittings use additional comb fixation with a split retaining ring.
American
Diameter: up to 32 mm.
These are the exact sizes of American women I saw on sale. Perhaps they are also produced for diameters of 40 - 50 mm, but I have not seen such offers in the assortment of local construction and online stores.
Wall thickness: any.
Advantages: extremely fast connection disassembly. To open the pipeline, you just need to unscrew the union nut.
Disadvantage: connecting pipes using an American method requires preliminary threading.
Technology: the halves of a disassembled American fitting are screwed onto the wound threads of adjacent pipes, and then tightened together with a union nut. Sealing is ensured by an annular rubber gasket.
Crabs
The so-called crabs are steel plates that allow you to connect round and profile pipes with bolts. They are used in assembling frames of greenhouses, shelving (commercial, for tools, etc.) and other structures that do not require special strength or tightness of connections.
Pipe sizes: diameter up to 25 mm; sections of profile pipes up to 20x40 and 25x25.
Wall thickness: any.
Advantages: allow quick assembly and disassembly using a pair of open-end or ring wrenches; allow repeated reuse of fasteners and pipes.
Disadvantage: limited strength.
Technology: the ends of the pipe are clamped between the halves of the “crab”, after which they are tightened with bolts and nuts.
A greenhouse assembled on “crabs”.
Polyvinyl chloride
PVC pipes are known, first of all, as the most affordable solution for installation of indoor and outdoor pipes. However, pressure socket pipes are also used for installing water pipelines.
O-rings
Compound PVC pipes using ring seals is practiced both in free-flow sewers and in pressure pipelines. The only difference is the thickness of the pipe walls and the force required to uncouple the socket.
Diameters: 50 - 600 mm.
Wall thickness: any.
Advantages: pipes are supplied completely ready for installation of the connection, with O-ring seals installed. When cutting to size for installation, couplings with two counter-directional sockets are used.
Disadvantages: large force required to assemble the connection with a large pipe diameter; possibility of spontaneous undocking of the connection.
Technology:
- Factory pipe ends are ready for joining. On pipes cut to size, the burrs are cleared and the outer chamfer is removed;
- Apply a small amount of liquid soap or silicone grease to the end of the pipe and the O-ring;
- The pipe is pressed into the socket.
If significant force is required for pressing, the following can be used:
- Clamp and lever systems;
- Loading equipment.
Adhesive joints
They are used when installing pressure pipelines. The glue is a solution of polyvinyl chloride in an organic solvent.
Diameter: up to 110 mm.
Wall thickness: any.
Advantage: the strength of the connection is almost as good as that of a solid section.
Disadvantage: the connection is made permanent.
How to connect PVC pipes with glue?
- The glue is applied to the inside of the socket and to the end of the pipe with the outer chamfer removed;
- A smooth section of pipe is inserted into the socket and rotates 90 degrees;
- The connection is fixed until the glue sets (no more than 1 minute).
Polypropylene
The only widely used method of connecting propylene pipes is socket welding. For this purpose, a monolithic polypropylene coupling is used.
Diameters: 20-110 mm.
Wall thickness: any.
Advantage: the connection is as strong as a solid pipe.
Disadvantages: required special tool(low temperature soldering iron); The connection is permanent and can only be cut.
Technology:
- The pipe is cut with a pipe cutter or a regular hacksaw;
- The outer chamfer is removed;
PN25 aluminum foil reinforced pipe requires stripping aluminum foil in the field of welding. For this purpose, a hand shaver or a drill attachment with similar functionality is used.
- The pipe is inserted into a soldering iron nozzle of the appropriate diameter heated to 240 degrees. At the same time, the second side of the nozzle is used to melt the coupling;
- The fitting and pipe are combined with a smooth translational movement and fixed until the polymer melt sets. The fixation, heating and cooling times are predictably determined by the pipe cross-section. For the convenience of the reader, I will collect all the recommended parameters in one table.
| Diameter | Heat | Fixation | Full cooling |
| 20 mm | 7 sec | 6 sec | 2 minutes |
| 25 mm | 8 sec | 10 sec | 2 minutes |
| 32 mm | 8 sec | 10 sec | 4 min |
| 40 mm | 12 sec | 20 sec | 4 min |
| 50 mm | 18 sec | 20 sec | 4 min |
| 63 mm | 24 sec | 30 sec | 6 min |
| 75 mm | 30 sec | 30 sec | 6 min |
| 90 mm | 40 sec | 40 sec | 6 min |
| 110 mm | 50 sec | 50 sec | 8 min |
Polyethylene
Polyethylene pipes are used:
- For laying pressure sewerage;
- As a material for cold water supply lines;
- When organizing country water supply systems;
- When installing a non-pressure sewer system.
When installing a polyethylene sewer system, the connection of HDPE pipes is no different from that for socketed PVC pipes with ring seals.
Black sewage pipe- polyethylene.
For pressure water pipes, two principles are used: different ways installation
Butt welding
Diameter: from 40 to 2400 mm.
Wall thickness: from 4 to 70 mm.
Advantage: the strength of the seam reaches 80% of the strength of a monolithic pipe.
Disadvantage: when joining large diameter pipelines, expensive equipment and mechanical or hydraulic devices for centering and clamping are required.
The pipe clamping force during butt welding should reach 1.5 kgf/cm. In this case, the cross-sectional area of the pipe cut can amount to thousands of square centimeters.
Technology:
- The pipe ends only at right angles to the longitudinal axis;
- The ends to be welded are centered;
- A heater mirror is inserted between them;
- After melting, the mirror is removed, and the ends of the pipes are pressed against each other;
- After the joint has completely cooled, the burr (extruded polymer melt) is mechanically cleaned to inside pipes.
Compression fittings
How to connect HDPE pipes with a small diameter and insignificant wall thickness?
In this case, the already familiar compression fittings are used.
Diameter: 16 - 32 mm.
Wall thickness: any.
Advantages: simple installation without tools, quick disassembly.
Disadvantage: relatively low tensile strength.
Technology:
- A union nut, a locking ring and a rubber or polyethylene seal are sequentially put on the pipe;
- Its end is inserted into the fitting;
- The nut is tightened, compressing the pipe with a seal.
Metal-plastic
Metal-plastic is two layers of cross-linked (reinforced by cross-links between polymer molecules) polyethylene with a thin aluminum tube between them. During installation, three connection methods are used.
Compression fittings
Diameters: any.
Wall thickness: any.
Advantage: the use of simple hand tools. I usually use to assemble the fitting a pair of adjustable wrenches.
Disadvantage: connection quality depends on the right technology assemblies. If the pipe is not calibrated, the displacement of the rubber O-rings along the fitting will lead to a leak after several heating and cooling cycles.
Technology:
- We cut the pipe with pipe cutter scissors;
- We calibrate it and remove the internal chamfer;
- We put a union nut and a split ring on the pipe;
- Apply silicone grease to the fitting fitting;
- Carefully, so as not to displace the o-rings, put the pipe onto the fitting;
- We move the split ring and nut towards the fitting until it stops;
- Tighten the nut until you feel resistance.
Press fittings
Their only difference from the previous solution is that instead of a union nut and a split ring, the pipe is crimped onto the fitting using a stainless steel sleeve.
Diameter: any.
Wall thickness: any.
Advantage: a correctly made connection does not leak under any temperature changes.
I suspect that press fittings do not leak only because, when installing them, professionals are not lazy in calibrating the pipes and chamfering them. According to my observations, a connection assembled according to all the rules using compression fittings is not inferior in reliability to a press fitting.
The photo shows a plastic tee with two push-couplings and an adapter for pipe threads.
Diameter: any.
Wall thickness: any.
Advantage: easy assembly without tools.
Flaws: high price fittings, moderate tensile strength of the connection.
Technology: the end of the pipe is inserted into the fitting with a previously loosened nut, after which it is tightened. The pipe is fixed with a metal ring with legs directed inward. Tightness is ensured by an o-ring rubber seal.
To learn how to connect metal pipes without welding, you need to study in detail the methods for connecting these pipe materials. The thing is that pipelines are complex design from serial connection pipe-rolling assortment, measuring equipment, which are provided in the project.
Docking can be done various methods. When choosing the optimal solution, they are guided by the purpose of the highway and the conditions of its use. The diameter of the rolled pipe assortment is also taken into account.
When laying a highway, the connection method may be different. Some of them may be permanent, but dismantling and subsequent reassembly of the structure is possible.
And there are monolithic joints that cannot be dismantled without destroying the structure. Welding has gained the most popularity among monolithic joints. But this is far from the only method that allows you to connect sections of the pipeline; there are others.
Despite the high popularity of plastic, steel products are still used. Welded fastening is used very often, but making such a joint is impossible without special knowledge and skills. Therefore, many try to use options that allow you to connect in a different way.
Installation with threaded connection
How to connect iron pipes without welding will be discussed further, but in this article you can find out. To make docking, this method is very common.
The threaded connection can be located in places on the highway where conditions allow for constant monitoring of the joint. At the same time, it should be possible to carry out repair work if necessary.
Most often, threads are rolled using special equipment, but such work can be done independently.
It is performed in the following sequence:
How to connect without threading and welding
Next you will learn how to connect metal pipes without welding or threading. Speaking about connecting metal pipes, this method cannot be ignored, because it is very popular during installation work.
Installation work is carried out in the following sequence:
- Metal pipes prepared for fastening are cut off at the end parts. The cut on them should be made perpendicularly and ensure that it runs smoothly.
- A coupling is applied to the connection area. The center of the connecting element must be located exactly along the pipe joining area.
- Markings are made on the pipes with a marker; it will indicate the position of the fitting.
- The end parts of the connection are coated with silicone grease.
- One pipe is inserted into the connecting part according to the mark. After which, the second one is placed in the same center line with the first one, and only after that it is attached to the coupling. The marker placed with a marker will serve as a guide when dressing.
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Metal gas line connection
- The correct connection is checked like this. A soap solution is applied to the joint area. When soap bubbles appear on the surface, it is recommended to tighten the joint further.
Joining muffler pipes without welding
If a common problem arises with a rotten muffler flange, then you should think about how to connect the muffler pipes without welding. This is what it's all about. In this situation, there are several options.
The first option is to cook. The next option is to buy a new muffler. The third option is to look for alternative exits. In both cases, you need to pay a lot of money. If there is no severe rust on the muffler, you can use a clamp.
As practice has shown, such clamps have long been used by world-famous auto companies such as Volkswagen and Audi. And it should be noted that these devices in many cases have successfully replaced welding in car repairs.
To join pipes at an angle and for branches, other types of fittings are installed: elbows, transitions and others. The end parts of the parts for the joint must be cleaned, and the threads must be made with a high level of accuracy.
To increase the strength of the joint of these products, it is wrapped with a strand of flax, only the threads are first coated with white.
The short threaded part is characterized by such features. In the area of the two turns at the end, which are called runaway threads, the depth is usually shorter. This makes it possible to provide a more durable joint without welding, without using rungs and seals.
Two parts on the extended threaded part can be fastened without welding by means of a bend. On the first part there is a short thread, and on the other - a large one. The short one is designed for fastening with a coupling. A coupling with a lock nut is placed on the elongated thread. And the large thread allows you to adjust the length of the workpiece.
Squeegees are most often used when repairing a section of a highway that has become unusable. The connecting element and locknut are driven onto a large thread.
To mount the squeegee, a sealing thread is used. It is screwed to the end of a short threaded thread on a metal product.
Sometimes, when installing a drive, a bundle of FUM tape is laid between the locknut and the coupling. It is laid in three layers. Such a joint is performed like this:
- A coupling and locknut are screwed onto a large threaded thread.
- At the same time, a sealing thread is also taken. It is wound on the end of the coupling, which is tightly fitted with a lock nut.
- The tourniquet must lie in a chamfer; this is the only way that neither liquid nor steam can leak out.
Speaking about how to connect two metal pipes without welding, it is worthwhile to dwell separately on such an option as Gebo. In parts of the highway where the connection is in a difficult-to-reach area, this method turns out to be quite effective.
There is a misconception that joining a riser with such a part without welding is dangerous. But, properly mounted, this element can withstand very heavy loads. It must also be added that such a mechanism is different high stability to the influence of axial forces.
While maintaining temperature standards, such a part perfectly holds not only hardware, but also plastic.
Using the material outlined above, it is clear how to connect metal pipes without welding. Almost all of the proposed methods are suitable for inexperienced craftsmen, and allow you to connect products without expensive welding work, which requires high qualifications and special equipment.