Metal pipes for home heating

More recently, the market for heat supply and heating completely belonged to metal systems. But modern materials by leaps and bounds are entering our way of life and now people are increasingly wondering whether it is possible to use metal-plastic pipes for home heating? This is an urgent issue and we decided to voice the opinion of our website experts on this urgent issue.

General material characteristics

Metal pipes are a versatile modern material, it actually combines the advantages of metal and plastic products.

In fact, it is a multi-layer construction:

• Its upper and lower layers are plastic;
• The core is made of aluminum;
• And all this is combined with a special adhesive composition.

Material advantages

• Smooth inner polymer layer provides absolute resistance to corrosive processes..
• These pipes easily bend. And if we talk about private construction, where products of small and medium diameter are used, the lines can be bent with their own hands without using a professional tool.
• This material is designed for temperatures up to 95? С at an operating pressure of 6.6 atm.. Reinforced structures of increased strength are still produced, they can withstand up to 10 atm at the same temperature. Moreover, all such systems are not sensitive to sudden changes in temperature or pressure.
• Unlike metal, during operation structures of this material are much quieter.
• It is easy to install the heating system from metal-plastic pipes with your own hands.. If you have basic skills in plumbing, the instruction presented on the video in this article will be clear to you.

• Running marks of pipes used in domestic heating systems are sold in coils up to 500 m. That makes it possible to mount the system without intermediate connections.
• The service life of metal-plastic heating pipes, up to the rules of installation and operating standards, can reach up to 50 years.
• These pipes do not overgrow from the inside., which is quite important when installing a system powered by central heating in apartment buildings. Water in such systems has a lot of different kinds of additives.
• The diameter of metal pipes for heating is quite wide and ranges from 10 to 1200 mm.
• And finally, the cost of a metal-plastic pipe for heating is significantly lower than that of analogs made of ferrous or non-ferrous metals..

Cons of these pipes

• The outer sheath of the products, although related to damped materials, still supports combustion.
• Thin aluminum core, as well as plastic, is not able to withstand severe mechanical loads, so these lines are preferably protected in some way.
• The weak point is the connecting fittings for metal pipes. The diameter of the outlet of the fitting is smaller than the diameter of the pipe; this often causes deposits and gradual overgrowth of the system.
• If you do not comply with the modes of operation, the probability of separation of the pipe walls is high.
• In addition, this type of polymer is afraid of direct exposure to ultraviolet radiation. In other words, such pipes cannot be mounted on the sun.

Subtleties of installation

When choosing which metal-plastic pipes are better for heating, you should initially decide which fittings you will use. These designs are of several types, which need to be selected depending on the conditions of installation and the nature of the system operation.

Fittings for metal pipes

Crimp fittings closer to traditional connection. The principle of operation is simple here; a crimp elastic ring wraps around the pipe and is fixed with a shaped metal nut. The main advantage here is that these connections can be used several times, it is enough to change the gasket and can be installed again.

The big advantage is the low price of crimp fittings. But these communications cannot be hidden. Mechanical, threaded connection requires periodic prophylaxis. Gaskets wear out, thread loosens, therefore several times a year it is necessary to inspect and tighten the nuts.

Press fittings are now considered the most popular. It is not difficult to work with them, it is enough to insert the end of the pipeline into the sleeve and press it with a special tool. The metal sleeve tightly compresses the walls and provides a reliable, durable connection.

Press fittings can be mounted in hard to reach places, up to pouring into a concrete screed. They cost a little more than crimping. Of the significant drawbacks, experts indicate that these structures are closer to disposable, plus special tools will be required for their installation.

Recently, universal connections have appeared on the market, called push fittings. For their installation, no tool is required at all, everything can be done by hand. The pipe is wound up in a design, up to the stop and fixed. When pressure is applied to the system, the edge of the pipe is wedged into the push fitting.

The connection is durable and reliable. It is possible to assemble such a line, even without possessing proper experience, at least 2 times faster than using press fittings. These structures can be mounted in the coupler and, importantly, they can be rotated. The only negative is the high price.

Advice: when picking up heating from metal-plastic pipes with your own hands, it is cheaper to pay for push fittings and quickly do everything yourself than hiring people or paying for crimping guns for press fittings, which can no longer be useful at all.

A few words about the assembly technology

These products have unique flexibility, thanks to which they can be used both in the tee-circuit and in the collector scheme. It was already mentioned that metal-plastic systems are afraid of mechanical impact. Therefore, experts unanimously recommend using them for arranging a hidden heating system.

Important: answering the question whether it is possible to put metal-plastic pipes on heating, the experts unanimously answer that the system has a warm floor, this is the best option. For reliability they are inferior even to copper or brass.

In order to avoid the formation of air pockets, the installation of the system should be carried out, observing a 3 mm rise per 1 running meter of the system, towards the water intake fittings.

As a rule, metal-plastic pipes are mounted in a box or laid on the floor. But in case of need open laying, the technology demands to fix the line with an interval no more than 400 - 500 mm. Otherwise, the pipes will sag over time, which can lead to the formation of air pockets.

Pipes are cut exclusively with special scissors. You can use a hacksaw, but the cut may not be even and experts do not recommend using this method.

After trimming, the edges of the pipe must be machined with a special tool, a calibrator. It will ideally align the walls of the pipeline and chamfer at the cut point. The compound prepared in this way will be tight and airtight.

The video in this article shows the details of working with metal-plastic.

Conclusion

Heating system, assembled from metal pipes, the design is quite reliable. But after the end of installation, it is necessary to check it with increased pressure. The construction must withstand the pressure of at least 1.5–2 times the working day.