How to weld a pipe with water with electric welding

Eliminating the causes of engineering communications failures sometimes requires quick solutions in order to avoid serious threats to building structures and irrecoverable loss of material values. The main thing is not to jeopardize the life and health of people. In some cases, it is not possible to turn off the water supply. An urgent repair of the pipeline is required under the operating pressure of the network.

Types of pipe welding with water

The share of pipelines with threaded connections is negligible. In most cases, the joints of the track metal elements are welded. Sometimes there are unforeseen accidents associated with installation errors, critical external load on the pipes. Leaks and cracks appear.

If the section requiring repair is made of a plastic pipe, the accident can be eliminated either with a clamp, or after completely shutting off the water supply. The temperature required to weld polymer elements will be devastating for a track containing pressurized water. Polypropylene becomes ductile at 95-130 ° C, and welding is performed at higher values. The electrical coupling has an operating temperature range of 250 to 300 ° C.

Metal pipes can be repaired. A qualified welder has the necessary experience to properly weld a water pipe under working pressure. You can eliminate the leak in the following ways:

• Electric arc welding is the best reliable way to eliminate an accident.
• Gas welding - you need a generator and an oxygen cylinder. It is very difficult to warm up the metal in a pipe with water, therefore, in some cases, this method has to be abandoned;
• Cold welding - the principle of sealing a leak is based on the hardening of soft active substances under the influence of low temperatures, air, or after the required time. Cold welding is suitable for hot and cold water pipes.

Electric welding is the most acceptable option for high-quality repair of a pipe with water. Modern devices are popular with home craftsmen. In the construction of trunk pipelines, a semiautomatic device is widely used; for independent work, it is better to purchase a compact hand-held electric arc device. The welding inverter is affordable, anyone can perform basic household operations.

In emergency cases, you can make a homemade clamp as an emergency measure, use a set for cold welding. After that, overhaul should be carried out in the near future.

Features of welding a water pipe

For a strong reliable connection, it is necessary to leave a gap of 1-2 mm, then the molten metal forms a seam with a reverse flow, the edges of the pipe are evenly connected to each other at the molecular level. A gap less than 1 mm in size with this quality is more difficult to connect. The pipeline is first assembled, then water is connected. Separate elements of the system are checked with special equipment for the reliability of crimping under high pressure.

Welding of main pipelines is done by electric arc devices. The method is guaranteed to withstand the required service life if the technological conditions are met. Pipe diameters less than 50 mm in the distribution of houses are often made with gas equipment. In conditions of limited space and a lack of qualifications of performers with the skills of an electric welder, this method turns out to be preferable.

During repairs, gas welding is also used more often. However, if it is impossible to turn off the water supply, the method is not used. The temperature of the section to be welded does not have time to reach the required values. Water cools the metal; a reliable connection will not work. The only option when this method is used without shutting off the main supply is if there is an internal shut-off valve above the leak, allowing pressure to be relieved in this section. If the design of the system allows an airlock to form, there is a chance to weld the fistula well.

The fundamental difference between gas and electric arc equipment is that in the second case there is no need to warm up the metal. It picks up the required temperature in a split second.

Hot steam is hazardous and can cause burns. It is not recommended to weld the hot water pipe with electric welding. In the event of a breakout, the consequences can be dire. Work is performed in a mask, gloves, overalls. High humidity is dangerous for the risk of electric shock. When performing work, it is necessary to observe safety precautions when connecting to the network, placing cables.

Leak repair by cold welding

Repair kits for home and professional use are sold on the market and in specialized stores. In terms of chemical composition, these drugs differ from each other, but a characteristic feature is the ability to solidify without the use of additional equipment. The plastic mass is kneaded before use, combined with a hardener, then applied to the fistula in the pipe. All work is carried out in rubber gloves. In their soft state, cold welding substances can be harmful to the skin.

When repairing leaks in a water system, a serious problem arises. The elasticity of the mass does not make it possible to withstand it for the specified time in the desired area. A trickle of water penetrates the soft compound before it hardens. In this case, the option of additional strengthening in the form of a temporary bandage, clamp is possible. After preparing the required mass of the drug, it is clamped between the pipe and the reinforcing element for the time of hardening. You can use a factory, homemade clamp and a cold weld gasket. Cold welding for pressurized domestic water supply pipes requires the utmost care and precision.

The recommendations of the product manufacturers guarantee the elimination of cracks and gaps on the pipes when the water supply is turned off, therefore, when working in an area with working pressure, special care, attention and accuracy is required. The instructions indicate the curing time. It is necessary to withstand it strictly. Polymerization occurs from 10 minutes to an hour.

It is not recommended to connect water after 8-24 hours depending on the type of cold welding. When using a temporary clamp, it should not be removed after polymerization. It is necessary to withstand the full time recommended by the manufacturer.

Features of manual arc welding of pipes with water

The work can be done satisfactorily only by clearly understanding the task at hand. First of all, it is necessary to inspect the damaged area. Welded pipes are more susceptible to the danger of leaks than solid-drawn counterparts. At the junction, a fistula is formed in the form of a crack. To determine the nature of the damage, it is recommended to go through this area with a sandpaper. The place of the fistula, its size, shape becomes visible.

A particular difficulty in work arises when repairs need to be carried out in a hard-to-reach place. Skills, knowledge of special welding technologies are required. Experienced craftsmen use a mirror and an electrode bent at a slight angle to facilitate the work. The specialist clearly distinguishes between molten metal and the resulting slag. An inexperienced performer may not notice the nuances, and the quality of the seam will be insufficient for long-term use.Such repairs will last for a year or two, then the pipe will leak. It is better to trust the work to a specialist.

Welding pipes is considered a complex operation. The qualifications of a master who worked only with structural construction steel may not be enough. With water pressure, the operation becomes more difficult. It is highly recommended that this activity be held as a temporary measure.

GOST does not provide for welding under pressure. The operation involves the emergency elimination of the accident. At the first opportunity to turn off the water supply, it is necessary to carry out major repairs, replace the damaged area.