How to connect pipes without welding

Connections by detachable methods

Absolutely all pipe connections can be divided into two main types:

Removable connections.
Permanent connections.

The choice of connection type depends on the material from which the pipes are made. Detachable connections, in turn, are divided into:

Coupling.
Flanged.
Threaded.

The first two types are considered examples of a threadless connection.

Threadless flange connection

Threadless flange connection is used for PVC pipe connections. It is made using cast iron flange fasteners with a rubber gasket. The sequence of steps when making a flange connection is as follows:

At the junction, it is necessary to cut the pipe; you can not make a chamfer, but

the cut should be without a single flaw.
The loose flange is put on the cut.
Then a rubber gasket is put on, and so that it protrudes 10 cm from the cut.
A flange is superimposed on the gasket and fastened to it with bolts equipped with counter flanges.
Bolts are fixed without much physical effort.

Threadless union connection

When repairing a pipeline and for connecting pressure and non-pressure pipes, pipe couplings are used. The clutch is installed in the following order:

The ends are cut at right angles.
We apply the coupling to the junction, its central part should be exactly at the junction of the pipes.
It is necessary to put marks on the pipe showing the location of the coupling.
The ends to be joined and the coupling are treated with special grease from the inside.
One of the pipes is inserted into the other to the limit.
It is necessary to join the pipes so that they are uniform in the longitudinal axis; a coupling is put on the second pipe according to the marks applied to it at the beginning of installation.

Advantages and disadvantages of semi-automatic welding without gas

The use of semi-automatic welding without gas, in comparison with traditional technology in an inert or active gas environment coming from a cylinder, has both pluses and minuses. The advantages include:

mobility of equipment - no need for a bulky gas cylinder and additional hoses;
no need for constant refueling of the cylinder and the associated economic costs;
the possibility of forming a more accurate seam;
the possibility of direct observation of the welding process (through a protective mask);
the ability to influence the parameters of the arc and the chemical structure of the weld by using flux with different fillings.

Among the shortcomings of semi-automatic welding without gas, experienced welders note:

significant price of a wire electrode with flux;
the need for gentle operation of the wire due to its fragility;
the difficulty of choosing the optimal welding mode - it is determined by the chemical composition of the flux;
the need to clean the seam from slag;
the need for a semi-automatic welding machine to have the ability to change polarity.

One of the most promising areas in this area is semiautomatic welding without gas.

Semi-automatic welding without gas at home is very popular. The necessary equipment, high-quality and inexpensive, is easy to find in specialized stores. The absence of a bulky gas cylinder makes the welding process much more convenient, and the quality of work remains high. But a novice welder needs to take into account the high cost of flux-cored wire and get preliminary advice from an experienced specialist.

Choice of electrodes

For welding stainless steel with a DC inverter, it is allowed to use electrodes with a base coating based on calcium and magnesium carbonates. Popular domestic brands include OZL-8 and TsL-11. They are inexpensive, but experience is required for work. The electrodes are prone to sticking, do not hold the arc well, however, the seams are obtained with sufficient anti-corrosion characteristics.

The best results are obtained if the universal electrodes with rutile coating are chosen for the job. They weld on direct and alternating current common grades of stainless steel. OK 67.60 electrodes, which are produced by the Swedish company ESAB, are recognized as the best. They are easy to ignite, hold the arc stably, and the amount of splashes of molten metal is reduced. Working with rutile marks, even a beginner will put a strong seam.

In manual welding, it should be borne in mind that the cooling slag begins to spontaneously rebound. Therefore, at this time, you need to be located at a safe distance so that it cannot get into the eyes or on open areas of the skin.

Machine setup

Before welding stainless steel with an inverter, it is necessary to set the settings using the switches on the front panel in accordance with the parameters of the workpieces to be joined. The value of voltage and current, depending on the thickness of the parts, is determined according to the table:

metal thickness, mm	Electrode diameter, mm	Voltage, V	current value, A
1,5	2	13	40 — 60
3	3	15	75 — 85
4	3	16	90 — 100
6	4	18	140 — 150

When performing argon-arc and semi-automatic welding, the gas flow is adjusted within 6 - 12 l / min. The wire speed is set by the mode switch. The larger it is, the smaller the penetration depth.

How to plug a water pipe without welding and threading

» Articles » How to plug a water pipe without welding and threading

Blocking methods

Threaded plug for steel pipes

The easiest and most reliable way to seal pipes is to prepare a thread at their end and install a plug of a suitable diameter.

Some home craftsmen advise in such a situation to use a metal bolt of the appropriate size, which is hammered into the hole and then scalded around the circumference of the pipe.

However, the use of these techniques is possible only in the case of a satisfactory condition of the end part of the metal pipe.

In the event that the condition of the blocked area is assessed as "dilapidated" - you will not be able to use the options listed above. In this situation, the proven “old-fashioned” method is used, which involves driving a wooden plug of the appropriate size (the so-called “chopik”) into the pipe hole.

Such a “plug” is recommended to be made of waterproof wood, which is treated with resin in order to protect it from decay. Some time after driving into the pipe, the chopik swells and reliably blocks the hole from leaks. As for plastic pipes, it is not recommended to use wooden plugs for their plugs.

Sealing plastic pipes

Immediately, we note that there are two types of sealing plastic pipes: permanent and temporary. The choice of one or another blocking method is determined not only by the pipe material, but also by the condition of the entire pipeline as a whole.

Polypropylene plug

So, temporary sealing is used for difficult access to the pipe and involves the use of a special polypropylene plug with an internal thread. Before installing it, an external thread is cut on the plastic pipe using a die of the appropriate size.

With external thread

Note! To permanently block the plastic channel, it is best to use a special welding device (soldering iron). The adhesion of elements in such a compound is carried out at the molecular level, which provides it with the necessary strength.

We also note that with the help of a soldering device you can fix a regular plastic plug on the pipe.

without thread

Materials and tools

To carry out work on blocking water pipes of an arbitrary type, you will need the following tool and consumables:

a hacksaw for metal or the so-called "grinder";
file (rasp) for removing burrs from the ends of pipes;
sharp mounting knife;
threading tool (if necessary);
plugs and threaded plugs used for temporary and permanent blocking of pipes;
silicate glue (sealant);
welding fixture with a set of nozzles or a building hair dryer (for sealing plastic pipes).

soldering iron

In conclusion, we note that the work on blocking the end holes of pipes, as a rule, does not require special skill from the performer. At the same time, almost all working tools (with a few exceptions) are always available in any household.

Last edit: 03/06/2015 Vadim

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Which inverter is suitable for welding stainless steel

For welding stainless steel, an inverter welding machine of any brand is used. For work at home, the simplest model is chosen. Craftsmen even make home-made devices that are not inferior to factory counterparts in terms of characteristics. The inverter must be with manual welding mode (MMA) and current adjustment within 20 - 200 A. For stainless steel welding, the following options are desirable:

the "Forcing" mode, which allows you to briefly reduce the arc voltage with a simultaneous increase in the current value;
PV (duration of continuous operation, indicated in the instructions) is not less than 40%;
the length of the cables is not more than 6 m, otherwise, due to the large power loss, they will become very hot;
maintaining performance with significant changes in voltage in the mains.

Tape FUM for sealing threaded connections

When assembling a pipeline on threaded connections, it makes sense to carry out additional sealing. For this purpose, a sealing tape (FUM tape) is often used.

The FUM tape is used in the assembly of gas, water supply and heating systems, as well as in the installation of technological pipelines that conduct substances with a temperature of -50 to +200С.

This sealing tape is made on the basis of fluoroplastics.

The FUM tape contains 80-85% fluorolone and 16-20% vaseline oil as a lubricant. Fluorolone is resistant to alkalis, mineral acids and other aggressive media.

For the purpose of sealing threaded connections, a tape 0.08-0.12 mm thick and 10-15 mm wide is used. The tape should have a flat surface without swelling and breaks.

The tape is white, there may be minor spots and blotches of other shades.

Features of car body welding

Car body repair requires high-quality welding equipment. Work is carried out in a room where it is possible to connect energy-intensive equipment to the power grid. A high qualification of the performer is required, since welding of thin metal will be required. A universal way to repair a car body has not yet been invented, therefore, depending on the location and nature of the damage, different technologies are used. Connections are made by gas, manual, semi-automatic welding.

Wings, sills are most often repaired by spot welding. The overlap connection is used to restore the integrity of the strength elements. Butt welding is used when replacing damaged elements.

Pipe welding

If it is not possible to connect pipes using threaded fittings, then you can use the welding method.

Welding of metal pipes

To connect a metal pipe without a thread, using, you will need:

welding machine;
protective mask;
basic equipment handling skills.

Device for welding metal pipes

The pipe welding process consists of the following steps:

chamfering from the pipe section at the place of the proposed seam;
preliminary cleaning of the place of the future joint;
connection of pipes by the device. Docking of pipes is carried out by melting the metal with an electric current;
cleaning the finished seam.

Pipe connection by welding

When welding pipes, the sections to be joined should be located as exactly as possible to each other. Otherwise, the seam will not be strong.

Welding of plastic pipes

To connect pipes without threads made of plastic, you will need a special welding machine.

Device for connecting plastic pipes by welding

To solder plastic pipes, you must:

heat the equipment to operating temperature;
clean the ends of the pipes from dust and dirt;
heat the ends of the pipes on the equipment and connect the sections together.

The joined fates must be held tightly pressed against each other for about 10 seconds. This time is required for the cooling of the pipes and the reliability of the seam.

You can learn more about the soldering process by watching the video.

One-piece connection methods

Socket connection method

Pipe wrenches: a - lever, b - sliding, c - cap; 1 - fixed lever; 2 - movable lever; 3 - nut; 4 - clip; 5 - movable sponge; 6 - spring; 7 - cap sponge

This type of sewer pipe connection is a type of permanent connection. With a permanent connection, the elements of the pipeline are separated with a violation of the integrity of the pipe or fastening. This method is carried out by welding or gluing. When using it, you should follow the instructions:

The smooth end of one pipe and the socket with the rubber ring of the other are connected. These parts are cleaned of dirt, degreased and checked for the absence of various defects. The bell rubber seal must be in the correct position and not damaged in any way. The smooth end must be chamfered.
The mating surfaces must be lubricated with silicone grease; this is necessary to prevent dirt and dust from settling on them.
The position of the connecting pipes is corrected, their longitudinal axis must match; a smooth end is inserted into the socket.
The pipe has a mounting mark, beyond which it should not be pushed.

Connection by welding

As mentioned above, permanent connections are made by gluing or welding. Two types of welding are known today:

Butt welding.
Socket welding

Crimp connectors for steel pipes.

When pipes are socket welded, the welder simultaneously fuses the outer surface of the smooth end of one pipe and the inside of the socket of the other. Then the parts need to be quickly connected.

Butt welding involves melting the connecting ends, as well as their connection using moderate pressure.

Welding requires special equipment. Because of this, not all types of welding can be performed at home. The most common of these are gas electric and arc welding. Before starting welding work, it is necessary to carry out preliminary preparation.

Preparatory work includes washing the oily areas with a solution of caustic soda (caustic soda), after which they are rinsed with warm water. The places of the intended connection must be processed with a file, cutting off the edges, and with a solvent.

Equipment for gas welding has an elementary principle of operation. The burning gas forms a flame that melts the filler material and makes a welded joint.As a filler material, a wire is used, laid in the gap between the ends to be connected. Using gas welding, you can connect polymer and metal pipes.

Arc welding involves bonding through the use of consumable (carbon) or non-consumable (tungsten) electrodes. When using a consumable electrode, the use of filler material is also necessary.

Efficient welding is a guarantee of the absence of fistulas and other flaws, and the weld is not conspicuous.

Connection by gluing

There is another type of permanent connection - adhesive. To use this method, you need to purchase a special glue that needs to be coated with the connecting ends. Depending on the type of surface to be glued, there are different types of glue:

For metal and plastic pipes - BF-2 glue.
For joints of polymer and metal elements - epoxy glue.
In "rubber + rubber" or "metal + rubber" connections, 88N is used.

Polyvinyl chloride pipes are interconnected by gluing. It is carried out in the following order:

The connecting areas are sanded and degreased using a special compound based on methylene chloride.
The degreasing kit may include a special glue for PVC sewer pipes, which degreases and slightly dissolves the pipes in order to make their connection stronger and more durable.
Then the treated ends are lubricated with a brush or swab with glue and inserted into each other. If glue is released at the joint, the fastening is carried out correctly.
The joint of pipes for high tightness is re-coated with glue.

Gluing must be carried out very quickly: in air, it quickly loses its adhesive properties, so after applying it to sewer pipes, immediately fasten them. The interval between stages should be a maximum of 90 seconds.

Common rules for installing pipelines

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

Upon completion of the installation of the pipeline, 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 along the circumference of the pipe, at the end the location of the ring in the socket is checked: the distance from the plate to it must be the same around the entire circumference.

In the case of pipeline installation at sub-zero temperatures, it is necessary to perform the work with extreme caution and use only silicone grease. If the pipeline is mounted by the socket method in a residential (warm) room, then liquid soap can be used as a lubricant for their smooth end and socket

The process of welding stainless steel with an inverter at home

Before welding stainless steel with an inverter at home, the workpieces to be joined are prepared in the following order:

Dirt and debris are removed from the surface near the joint, it is cleaned to a shine with sandpaper or a brush with a metal pile.
The junction is treated with a solvent to remove grease. Otherwise, it will break the stability of the arc.
When joining workpieces with a thickness of more than 4 mm, chamfers are removed from the edges at an angle of 45⁰ for better filling of the joint with molten metal.
To prevent splashes from sticking to adjacent surfaces, they are treated with an aqueous solution of chalk.
To compensate for the thermal expansion of the workpieces to be welded, a gap of 1–2 mm is left between them.
Welding of stainless steel up to 1 mm thick is performed without a gap.
To prevent overheating of the metal at the junction, the workpieces are placed on aluminum or copper plates.
Parts thicker than 7 mm are preheated to 150⁰C to reduce the temperature difference at the start of welding.
To remove moisture and improve the properties of the coating, the electrodes are calcined by placing them in an oven before use. In cases where the work is done urgently, let's warm up with a gas burner.

DC welding is carried out on reverse polarity. The connection is made with a short arc at a speed greater than for ordinary steel. The electrode is guided along the seam without transverse movements. It is tilted at an angle of 40 - 60⁰ to the side convenient for holding. Due to the high resistance to electric current and poor thermal conductivity of stainless steel, the electrodes burn out faster than on ferrous metals. This phenomenon comes as a surprise to beginners. The seam is completed with a “lock”, which will prevent the formation of cracks and fistulas. The weld pool is shifted to the surface of the workpiece or returned a little back. Without changing the position of the electrode, the arc is extinguished. Since it will not work to weld a thick stainless steel in one pass, the operation is repeated several times until the joint is completely filled.

After welding is completed, wait for the joint to cool down. You can not spray it with water, as this will lead to the appearance of microcracks. The slag begins to be beaten after 5 minutes, so that no marks are left on the still soft metal. To give a presentable appearance, the junction is ground and polished. However, as a result of mechanical treatment, the passivated layer of chromium oxide is removed from the surface, which protects it from corrosion. The restoration of the film occurs in 4 - 6 hours, during which the stainless steel remains unprotected. To speed up the process, the surface is treated with a composition containing passivating additives. After half an hour, it is washed off with water.

After reading the above recommendations, the answer to the question: “Is it possible to weld stainless steel with an inverter?” obvious. However, this does not mean that a beginner will be able to make a reliable connection the first time. To develop skills, you will have to practice on unnecessary scraps, preferably under the guidance of a mentor.