Apparatus for welding polypropylene pipes
Currently, almost exclusively plastic, mainly polypropylene pipes are used for water supply and heating. Their advantages over metal are obvious: lightness, strength, environmental friendliness, low energy consumption in production and installation. However, their use requires special equipment: a welding machine for welding polypropylene pipes. About which device to choose and will be discussed in this article.
Types of welding machines and their technical characteristics
The device for welding polypropylene pipes is designed to heat the ends. The ends are then brought into contact and welded by diffusion. It requires much less energy than for welding metal. The power of the devices ranges from tens of watts to several kW. Since the pipes differ in diameter and technology of their manufacture, the machine for welding polypropylene pipes can have a variety of designs and equipment.
Welding machines for small diameters, up to 63 mm, are manual and have relatively low power. Their device does not contain mechanical drives and these welding machines are designed for piping in buildings and domestic premises.
They are usually purchased either by professionals involved in the installation of heating and plumbing, or by skilled homeowners who want to do their own repairs. Such welding machines are lightweight, up to several kg, the power they consume to heat up the tool is also small, on the order of several hundred watts, and they can be powered from a regular household outlet.
There are two types of welding machines. One, more common, contains a tapered metal plate to which heating nozzles of different diameters are attached. Such a welding machine has a low cost, moderate equipment, and home craftsmen usually want to buy it. The power of such devices is about 800-1000 watts.
Reviews show a good popularity of such models. In another variety, instead of a flat heater, a cylindrical one is used, on which it is convenient to turn the nozzles. This welding machine is used by professionals for the installation of polypropylene pipes in various hard-to-reach places. Which device to choose depends on a careful analysis of all considerations about the upcoming work.
Welding machines for welding large diameter polypropylene pipes look completely different. They contain grippers moving on a frame along the axis of the pipes being welded, which are driven by an electric drive and a pipe trimming machine. Heating is carried out directly in the gripping couplings, with the help of built-in heating elements.
Such welding machines are capable of welding polypropylene pipes of the largest diameter, starting from 125 mm. The power consumption of these devices is several kilowatts. Almost all of this power is spent on heating the ends. The cost of these devices is quite high and the buyers are construction companies or utilities.
There is also a method for welding polypropylene pipes with electric couplings. It is used in hard-to-reach and responsible places. A coupling with electric heating is put on the joint and the pipes are welded by supplying a certain current with a delay of a given time. Such a welder contains a special power source and a barcode system to document each joint.
Criteria for the right choice
Before deciding which machine to choose for welding polypropylene pipes, it is worth evaluating the range of pipes to be connected and the amount of work. It is hardly justified to buy an expensive professional kit for a home repair case. Selling such a welding machine for the second time with a profit will not be easy.
Conversely, a professional who wants to save money on buying a cheap welding machine may face failures at the most inopportune moment due to the failure of unreliable cheap equipment. The best results depend not only on the price of the device, but also on the experience of working with them.
First of all, the welding machine for polypropylene pipes has a number of diameters with which it can work. It is necessary to properly inspect your household (or project documents), rewrite all the diameters of the pipes and couplings used.
For a one-time repair, it is better to choose a welding machine at a low price with a minimum set of nozzles and other equipment. The set necessarily includes a case or case, as they say now, and this is a big plus in this case. The welding machine can be conveniently and compactly stored. As a rule, in the household there is a need for alterations or re-repair (for professionals this is a rarity).
For a specialist, the price is not of primary importance, such people are primarily interested in reliability during continuous operation of the welding machine, the variety and quality of accessories: nozzles and devices for trimming polypropylene pipes. A professional device must also be powerful in order to heat up faster and work at a lower ambient temperature. Specialists always choose the best quality devices.
With the frequent connection of polypropylene pipes of increased diameter, you will inevitably have to buy a mechanized welding machine, even if the diameter used still allows the use of a manual machine. Otherwise, it will be impossible to ensure the quality and timing of the work.
Popular manufacturers
The Czech company Dytron, the Turkish manufacturer Candan, and the Russian company Energomash (part of the Sturm group of companies) are now the most well-known on the Russian market. Each of them has its own advantages. Czech welding machines for polypropylene pipes are of high quality, a wide range of professional features and a high price. Of their manual welding machines, we can mention the professional device POLYS P-4 and the machine with the same brand from the P-1 series. The latter is intended for home repairs. Czech devices are the best in quality.
The Turkish manufacturer Candan belongs to the "compromise" in terms of price / quality. Its welding machines for polypropylene pipes are in great demand. They are quite reliable, and with proper use are almost trouble-free. Candan CM-01 polypropylene pipe welding machine is shown in the photo below:
The photo shows a heater, also called a "soldering iron" or "iron" with holes for nozzles of different diameters. This is a welding machine without installed heating sleeves. It is mounted on a massive stand. It is on the bottom of the photo. The plate with nozzles is heated by a stabilized thermostat, which has a temperature scale on the reverse side (not visible in this photo). And the video below shows how to handle it.
The video clearly shows the table in Russian, which is included with the Candan welding machine and allows you to accurately select the best welding mode. This is an important condition for obtaining a strong and tight seam. This video also demonstrates the complete set of the case from which it can be seen that this welding machine is clearly of a professional level. It also has the best price.
Candan manufactures several other welding machines, among which there is a welding machine for large diameter polypropylene pipes. In addition, Candan sells separate accessories for the machines: pipe straight cutting shears, and end-cleaning devices. Each of their welding machines includes a set of interchangeable nozzles.
Energomash welding machines are in demand among Russian enterprises. The photo below shows the Energomash ST-72250P device:
In this photo, as in the previous one, two switches are visible, each for its own heating element.
Welding machine Energomash ST-72250 is an analogue of Candan. Energomash produces a number of welding machines for polypropylene pipes. The photo shows a welding machine for polypropylene pipes from the side of the temperature controller. The ROSTERM welding machine is also produced in Turkey, but this is a Russian development.
Principle of operation
To understand how to use a welding machine for polypropylene pipes, you need to consider the physics of the materials used. When polypropylene is heated to its melting temperature, it tends to minimize its surface area, which causes its shape to change. At the same time, in this form, it is capable of diffusion, and this is welding.
It is only necessary to tightly join the parts (pipe ends or the inner surface of the coupling with the outer surface of the pipe) and allow them to cool, while maintaining the immobility of this assembly. After that, a seam is obtained that is not inferior in strength to the original material.
All these principles are technically implemented with Teflon-coated nozzles. Teflon avoids sticking to the heated surface of the nozzles. The shape of the nozzles allows you to heat the ends of polypropylene pipes from the outside and from the inside. When manually welding pipes of small diameter, couplings are used. The coupling is heated from the inside, and the pipe from the outside. Then immediately put the sleeve on the pipe and wait for solidification. From the other end of the coupling, the procedure is repeated for the second pipe in the joint. Get strong seams.
Otherwise, a welding machine is used for large diameter polypropylene pipes. Pipes are welded end-to-end, without the use of couplings. This allows the relative thickness of their walls (for thin pipes, when welding butt, it is difficult to obtain high reliability). Large pipes are centered with clamps on the machine. Electric heaters are built into the clamps. When the ends are melted, the clamps with clamped pipes are mechanically pulled together towards each other, using a lead screw, manually or, for pipes of the largest diameter, using an electric drive.
The ends of polypropylene pipes are pre-cut with special scissors, which ensure the perpendicularity of the pipe axis. There are also ways to connect pipes at an angle. It is more difficult to weld pipes with aluminum fittings.
Soldering reinforced pipes
Since polypropylene is thermoplastic, it can lose its shape in water heating and hot water systems. This means that pipes can sag, swell, etc. This is undesirable both because of the deterioration in appearance and because of the likelihood of depressurization.
Therefore, reinforcement is used, which is of two types: aluminum foil and glass fiber mesh. In the case of glass reinforcement, pipes are welded as well as pipes without reinforcement. In the case of aluminum, it's a little more complicated.
When welding pipes reinforced with aluminum foil, a groove should be made in the end to remove the foil. To do this, the pipes must be cut perfectly perpendicular to the axis with a special tool, and not with a hacksaw. Otherwise, the groove will be uneven. To cut the foil from the end, special devices are used, which are also included in the set of welding machines, for those diameters for which it is designed to work.
The photo shows a shaver, a tool for turning foil into a reinforced pipe. The knife is clearly visible, attached with a screw to the sleeve body. There are two such knives on the tool. It is put on a pipe of the appropriate diameter, pressed against the end and manually scrolled until the chips are removed to the full depth of the knife. Then, when welding, aluminum will not interfere with a strong seam. The photo on the right shows the finished groove.
Prices
Prices for welding machines can vary significantly. The cheapest are Chinese and Russian welding machines for manual welding, they have a cost starting from 1300 rubles. The Turkish ones have a higher price, and the most expensive are those produced in European countries. The Candan welder sits somewhere in the middle.
The difference is almost an order of magnitude. Which one to choose - the buyer decides. Czech devices POLYS P-4 cost about 13,000 rubles. The prices for some popular brands of manual welding machines are given in the table below:
| Apparatus: | Power, kW | Manufacturer: | A country: | Cost, rub: |
| ST-72180 | 1.8 | Energomash | Russia/China | 2500 |
| ROSTerm 20-40mm | 1.5 | ROSTerm | Russia/Türkiye | 3200 |
| V-Weld RF063 | 1.0 | Voll | Belarus | 4700 |
| PPR 600W 20-23mm | 0.6 | Sheng Hai | China | 2300 |
| Candan CM-01 | 1.5 | Candan | Türkiye | 4400 |
| Candan CM-02 | 1.5 | Candan | Türkiye | 5200 |
| Candan CM-05 | 2.4 | Candan | Türkiye | 8300 |
| P-4a-63650W TraceWeld SOLO | 0.65 | Dytron | Czech | 14600 |
| SP-4a TraceWeld PROFI | 1.2 | Dytron | Czech | 43500 |
| VTp.799.0.016040 | 1.5 | Valtec | Italy | 4100 |
| KERN Welder R40 | 0.6 | Kern GmbH | Germany | 4650 |
| KERN Welder R110E | 1.2 | Kern GmbH | Germany | 12300 |
Prices for mechanized devices (for large pipes) are 10-20 times higher than those given in the table. But these devices are intended for work already at the communal and building level or for industry and are not used for household or office premises. The price of a welding machine for polypropylene pipes depends, first of all, on the diameter of the pipes to be welded. Consumer reviews speak in favor of more expensive models. Reviews of experienced craftsmen about inexpensive models show that you need to be able to use the device.
