The metal pipeline in modern construction is considered an outdated technical solution. They try to use either copper pipes or pipes made of synthetic materials: composite plastics, polypropylene and polyethylene. It is important not only to choose which pipes to use for creating water and sewer systems, but also to know how to use them correctly. to connect.
Welding of plastic pipes is carried out by hot and cold methods.
Content
The advantages of plastic pipes and methods for their connection
The advantages of plastic pipes include the fact that they do not rust, they are convenient to install, they require minimal maintenance. As for the installation, it is simple, but has its own specifics. The principle of a threaded sleeve connection of system elements is well suited for wiring metal water pipelines, but is completely inapplicable to plastic pipes.
The physical properties of synthetic thermoplastic pipes allow you to create a reliable connection. Multicomponent materials make it possible to connect plastic pipes without welding, for example, to repair elements of water systems in hard-to-reach places. Adhesive bonding is also called "cold welding". The simplest, fastest and most reliable way to connect plastic pipes is welding, which requires a high temperature.
The main advantage of mounting in a welded way is that the welding of plastic pipes with your own hands has ceased to be an operation available exclusively to professionals. The greater the practical experience of welded installation, the higher the chances of creating a perfect joint. Tools and equipment can play a crucial role in the installation of communications.
Reliability of joining plastic pipes depends on the quality of the fittings and the welding method.
Professionals use high-quality, reliable tools and branded equipment. Fans are satisfied with the mid-range tools. It makes sense to initially purchase the necessary materials and equipment of high quality.
Minimum installation error fittings, reliability of components, high-quality weld are the advantages of high-quality components. Disadvantage: the relatively high cost of premium plastic pipes.
DIY plastic pipe welding equipment
The following components will be present in the novice wizard set:
- soldering iron for soldering polypropylene (plastic) pipes. As a rule, it is sold complete with a metal case for transportation and a set of nozzles of the most common diameters;
- edged pipe scissors. They have a bent lodgement, a cutting blade and a node of stepwise increase in force. Using special scissors, it is much more convenient to cut the pipe than with a knife or file;
- roulette. "True friend" of each builder and professional engineer;
- marker. They note the boundaries of the cut and the depth of entry of the pipe into the nozzle during heating during welding.
Professional equipment includes a semi-automatic device designed for welding for plastic pipes. It is necessarily completed with a fixing unit for pipes with a diameter of 50 mm or more.
A compact heater is used to weld small pipes.
The set of this master certainly includes:
- construction level, they verify the accuracy of the laying of the highway;
- scraper for reinforced pipes;
- mounting knife (beveled working part, robust construction);
- set of electrical fittings. In some cases, the installation of plastic pipes is possible only when using electrical fittings - special welding, technical conditions for wiring and operating systems;
- special thermometer for monitoring the heating mode of the welded surfaces;
- high-quality electric extension cord;
- liquid for cleaning soldering iron tips.
After welding plastic pipes and thoroughly checking the system, each connection is inspected individually to detect leaks. In case of successful installation, there are no problems. Professional equipment will serve the owner even after wiring communications - a good soldering iron for plastic pipes is easy to rent!
Important! For welding plastic pipes of a small diameter (up to 40 mm), you need to know the sequence of actions, have a minimum practical skill in assembling communications and a set of available tools. The temperature and the heating time of the pipes and fittings are also important.
High temperature plastic pipe welding method
Plastic pipes are welded using special equipment. This is welding for a plastic pipe, it is also a soldering iron for pipes made of plastic, also called an “iron” for the similarity of inexpensive models of soldering irons with this household appliance. The soldering iron of the class above has the form of a metal pipe with an insulated handle and an integrated stand, the temperature is adjustable, and there is a ready-to-work indicator.
Before welding plastic pipes, they must be prepared: cut to the required length and strip the surfaces to be welded. It is difficult to realize a high-quality connection if the cut of the plastic pipe is not perpendicular or deformed (oval). This applies to pipes of any diameter.
Before starting welding, the pipe section must be cleaned
It is convenient to cut plastic and polypropylene pipes using special scissors. The sharper the cutting blade and the larger the shoulder of the gear unit (longer than the scissor handle), the easier and more convenient it will be to work with the tool. An even cut on a large-diameter pipe can be achieved with a crosscut.
Reinforced pipes must be processed using a special device - a washer. The edge of the plastic pipe being welded is cut at an angle to avoid the appearance of an inner flange (weld), which inevitably leads to a decrease in the inner diameter. As a result, the unbalanced operation of the water supply system and poor-quality connection of its elements.
The next stage of preliminary preparation is the degreasing of the surface of plastic pipes and fittings in the places of welding. Factory-fitted fittings, such as valves and fittings, may not require additional surface cleaning.
Components for cleaning: tangit or alcohol. Use a dense cotton cloth, wipe the tips of the soldering iron with the same cloth for the plastic elements of the plumbing system.
Important! The Teflon layer (coating of soldering iron nozzles for pipes) is easily damaged when cold. To remove the crumbs of plastic that adhere to the nozzles, you need to be extremely careful using wooden chips or non-synthetic fabric. The nozzles must be warmed to the state of melting of the plastic.
Incorrect welding of a plastic pipe, the temperature of which was insufficient to melt the surface, leads to the formation of a loose, weak connection. Naturally, such a connection will be durable and tight for a very short time.
Infrequently, and real professionals apply butt welding of plastic pipes. For this, special welding machine. The process requires painstaking preparation and an accurate comparison of the parts to be welded. The slightest skew - and the connection is hopelessly ruined.
Butt welding is carried out by professional welding equipment.
The way how to weld a plastic pipe is selected at the design stage of the entire water supply system.
Cold welding of plastic pipes. Types of materials used
The best option for repairing or optimizing an existing water supply system is to use a method called cold welding. There is no need to warm up a pipe or fitting, it is easy to carry out work on an installed water pipe branch from plastic pipes. The main advantage that cold welding boasts is the lack of bulky and expensive equipment.
Cold welding for plastic pipes is most often sold as a neatly packaged cylinder. Inside the package is a three-component composition:
- amine resin is necessary for the correct course of all stages of hardening;
- filler. Depending on the type of surfaces to be welded, a mineral or metal filler is used;
- epoxy resin. Time-tested component that gives strength to the hardened composition.
Special skills in working with cold welding are not required. The manufacturer kindly completes the instructions for each package. How to weld a plastic pipe, how to cook the surface - everything is indicated in the instructions.
It is necessary to adhere to a number of rules:
- Thoroughly clean the surface prepared for gluing or restoration. Cold welding is often used to restore the integrity of instrument housings or home appliances.
- To start the process of solidification of the components, it is necessary to cut off the “washer” of the required size from the total mass and carefully knead it in your hands. So that the mass does not stick to your hands, you must first wet your hands with water or use gloves.
- Apply on the surfaces intended for gluing a layer of softened composition. Connecting plastic pipes without welding is the only method for working in rooms with increased fire hazard.
- Thoroughly flush eyes and exposed skin with water after working with cold welding components.
When cold welding, avoid contact with the eyes of the chemicals that make up the adhesive mixture.
The cold welding method involves joining parts using special glue
Joining plastic pipes without welding
Create lasting plastic pipe joint and transition fittings, or directly from one pipe to another, it is quite possible without using welding.
How to connect a plastic pipe without welding? By gluing with a special adhesive (sold as a ready-to-use viscous liquid). It is allowed to use the gluing method if the master works with a low-pressure line.
Fast and extremely secure without welding polyethylene pipes. They use the fixation method using crimp rings and adapter fittings. A special tool is needed - crimping pliers - and a high-quality (Italian) fitting.
