How to choose a corrugated stainless pipe for underfloor heating?

For equipment in an apartment or in a residential building with underfloor heating, components and consumables are often used that are not fully suitable for such cases. An erroneous idea about the “warm floor” heating system itself, about how the equipment should function becomes the cause of frequent emergencies. To solve this problem will allow the exact following of the technology of laying a warm water floor, the use of materials specially designed for use in this case.

Main article: how to choose pipes for underfloor heating?

One of the elements on which the water heating system is based is a corrugated stainless pipe, specially designed for laying a warm floor. The product first saw the light in Japan, where, due to cramped living conditions in cities, attempts are constantly being made to find optimal engineering and technical solutions for laying household communications. Thanks to the successful combination of corrugations and stainless steel, it was possible to obtain a flexible and durable channel used as a pipeline for laying underfloor heating.

The pipes that will be discussed can be used as the main heating water circuit, and as wiring elements when connecting a warm floor, heating radiators to a heating device.

The peculiarity of the pipe, the raw materials and the manufacturing technology itself. For the production of corrugated products, special AISI 304 stainless steel is used, which is fed in strips to pressing and forming machines. After passing through a series of rollers and folds, the output is a cylindrical billet. After the conveyor, the stainless steel billet enters the welding machine, where, under the influence of a specially created gas environment, a welding seam is created.

On a note: a special gaseous environment ensures the preservation of alloying components in the metal during welding. When cooking in the open air, valuable alloying components evaporate, due to which the steel loses its stainless properties. Violation of the welding technology leads to the fact that the weld on the stainless pipe is quickly destroyed during operation.

As a result, after all the manipulations, a cylindrical channel is obtained, which is already ready for use. However, in order to give it all the necessary technological and design characteristics, it is necessary to anneal the finished pipe. The corrugation undergoes heat treatment under the influence of high temperatures, after which the stage of product cooling begins. The end product is a corrugated stainless steel pipe with high strength.

For reference: corrugated stainless steel pipes perfectly withstand dynamic loads, retaining their usual shape without succumbing to deformation. Comparing the annealed corrugation with the usual one, we can state the fact that when bending a conventional stainless channel, shape distortions may occur.

For distinction, annealed pipes are packed in cases, on which a special marking is applied. Otherwise, it is impossible to distinguish at a glance an ordinary stainless pipeline from a finished annealed product, which is often used by unscrupulous sellers.

To determine the optimal footage of a corrugated pipe for your heating system, just look at the following table.

Corrugated channel diameter in mm	The volume of water in a linear meter	Channel area
fifteen	0.219 l.	0.064652 m2
twenty	0.447 l.	0.09004 m2
25	0.71 l.	0.121394 m2
32	0.982 l.	0.15218 m2

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When buying a corrugated stainless steel pipe for your apartment, the main thing is to clearly follow the selection criteria:

• the first is that the corrugation step on the entire channel should be the same;
• second — the weld must be intact, even, without visible flaws.

For reliability, the corrugation can be tested for bending. The absence of obvious deformation and destruction of the seam indicates that the product meets all the necessary norms and standards. For fittings made to connect corrugated pipelines, an important point is not only the complete set of products, but also the condition of the sealing rings. To date, the range of manufactured fittings allows you to implement any connection option.

Pros and cons of stainless steel corrugated pipe

Due to its high technological characteristics and design features, stainless steel pipe is becoming more and more popular in private housing construction. The design features that corrugated stainless steel has allow you to immediately solve several technical issues, which greatly simplifies the installation of heating systems. Corrugated stainless steel hoses have the following advantages:

• pipe bending can be carried out manually, to any bending radius;
• the clearance of the hose at the bend does not change (min. d of the bend is equal to 3 times the R of the pipe);
• pipes are produced in coiled coils of 50 linear meters;
• easy and quick installation of the pipe with connection to heat sources and heating devices;
• a small coefficient of roughness reduces the rate of silting and clogging of the hose lumen;
• the service life of corrugated pipelines is limited only by the condition of the valves;
• hoses are lightweight, low noise threshold.

Here it is appropriate to say the following. The ability to easily bend hoses in any direction makes it possible to reduce the cost of installing a warm floor by reducing the number of connections. This feature plays a significant role in the reliability of the heating circuit. Other advantages that stainless corrugation has include the resistance of the material to corrosion, the ability to withstand pressure surges and temperature changes. The latter aspect is especially important when it comes to laying a heating system in a region with a harsh climate. Corrugated stainless steel hose is practically not afraid of defrosting.

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As for the pressure that the pipe can withstand, the parameters are as follows:

• max pressure 50 bar;
• max working pressure at t 110⁰C is 15 bar;
• max burst pressure (at 20⁰C) is 210 bar;
• The temperature range is from -50 degrees Celsius to 110 degrees.

As long as the list of advantages, the list of disadvantages that are characteristic of this material turned out to be so long. Particular attention should be paid to some of them, which are important and significant from a technical point of view. Stainless corrugated pipe is notable for insufficient resistance to mechanical damage. Such a detail requires providing the pipeline, located in an open, accessible form, with the necessary protection (casing). If you lay the pipeline in the open, the aesthetics of the interior will suffer greatly.

Corrugated pipe is highly susceptible to electrochemical corrosion. Destruction can be prevented by installing grounding and using dielectric spacers.

Important! When laying the hose for underfloor heating, it is necessary to use protective chemical screens. When filling the pipeline, it is important to take into account the composition of the coolant (using antifreeze).

When installing a warm floor using a corrugated pipe, you will need to regularly check the reliability of the connections. The high coefficient of heat transfer, which corrugated stainless steel hoses have, is also important. The heat carrier circulating through the stainless pipe of the heating system quickly loses its temperature, so it is best to lay the stainless hose in a concrete jacket, which will work as a heat remover.

All of these shortcomings take place, but with a competent approach they can be easily eliminated and turned into certain advantages.

Corrugated stainless pipes for heating. Mounting

Having numerous advantages, stainless steel corrugated pipe is a very convenient material for underfloor heating equipment. Corrugated pipes are especially attractive in the case of assembling a heating circuit pipeline. Here you only need a set of fittings and a key. Installation of hoses to all heat sources and heaters is carried out as follows:

• the pipe of the required length is cut off with a pipe cutter. It is important here that the cut be strictly perpendicular to the plane of the pipe itself. The cut must be free of burrs and roughness.
• Next came the turn of the fitting. It is important that he be in a tedious completeness. After inserting the hose into it, carefully tighten the nut. For better sealing, the nut is tightened with a wrench. Installation completed.

Similarly, the transition from a conventional pipe to a corrugated stainless steel hose is carried out. A riser or other pipe outlet is equipped with an appropriate fitting, at one end of which a corrugation is inserted. Then the sealing ring is tightened.

When installing a corrugated pipe, it is important to remember that it is quite flexible. If you lay a heating circuit for a warm floor, the pipe is fixed in special grooves. When installing piping on panels, fasteners should be installed as often as possible.

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Recommendations when working with corrugated stainless pipe

When using corrugated pipes in everyday life, you should follow the advice of specialists. According to professionals, a corrugated pipe has more resistance to water flow, in contrast to smooth-walled pipelines. Having a circulation pump of sufficient power freely solves this problem.

In urban apartments, such pipes are often used in conjunction with gas heaters. Stainless pipes are used to make heating system wiring, install underfloor heating in living rooms and bathrooms.

Laying a warm floor using corrugated stainless steel pipes is carried out according to the principle — one circuit — one bay of the pipe. Fittings in this case are not placed tightly. Better to use combs.

In most cases, with proper piping, observing a certain step when laying the pipe, you can achieve long-term and uninterrupted operation of the underfloor heating.

Use a corrugated pipe in the heating system — it’s up to you. What will be better metal-plastic pipe or stainless corrugation, time will tell. In any case, the ease of installation of underfloor heating using such materials shows how the material has taken root and is a good consumable for home heating systems. The only factor that currently makes stainless steel pipes in demand is the reliability and durability of the pipeline and connection points.