FLOATING FLOORS ACTUALLY FLOATING?!
THE INVESTOR GETS HORRIFIED AT THE MERE THOUGHT

Are you really sure you chose suitable materials for your water and heating installations with the best ratio of

TECHNICAL PERFORMANCE / QUALITY / PRICE?

Many people are still convinced that copper is most reliable and that despite considerable expensiveness it is a good investment which will pay back. In gutters and electrical installations, copper is almost eternal. Copper surface piping is also quite acceptable, except for its low vandal-resistance. But copper under wall surface or embedded in concrete is affected by the changes of length due to thermal expansion (self-expansion) and to structural expansion of the building. Besides, physical processes like subsidence of the building and plastic flow of the concrete mass endanger the copper tubes which are weak and have limited flexibility. The problem can be solved by the application of sleeve insulation to cope with these phenomena. Nevertheless, the biggest risk lies in unexpected electrochemical effects which corrupt both quick-soldered and slow-soldered joints. Copper is an excellent heat conductor and that is why copper piping for warm service water and for heating water has considerably higher heat loss that plastic piping. Thicker thermal insulation is only a partial solution to the problem because it makes the heat radiating surface larger.

Many of you will know that if made from unsuitable material with poor thermal oxidation stability, ascending pipes in a residential building need to be replaced after a few years of service. Decades of development in the field of plastic pipe materials for warm water distribution systems (under 95°C) brought the crosslinked polyethylene (PE-X) to one of the top positions. PE-X, a sort of infusible and unweldable thermoset, behaves like one big compensator of length changes in that it extends and contracts its walls without any detriment to the working life and solidity of the material. Pipes can therefore be embedded in concrete without ­sleeve insulation. For its perfect stability against thermo-oxidation degradation, especially a once-neglected kind of crosslinked polyethylene, type PE-Xb according to DIN standard, is a great favourite with all important producers and even with former opponents of the silane production method. Today´s stabilization procedures developed for PE-Xb also ensure a longer working life in contact with hot chlorinated water. Nowadays, special stabilization against copper ions degradation is taken for granted. In principle all types of PE-X, „a“, „b“ and „c“, have to adhere to DIN16892 characteristics. Their materials differ only beyond the limits of usability--one has better resistance below the freezing point, another can be repeatedly broken, and the third is more stable if exposed to temperatures over 200°C. But this is not what users are interested in. Oxidation processes in the heating circuit and the resulting cauldron, boiler or radiator corrosion are successfully suppressed by using barrier layers from EVOH to prevent the diffusion of oxygen in the PE-X tube wall.

This material is also based on PE-X. A trend of massive promotion of this kind of tubes on the market is slackening. The reason is the price which is much higher than the price of metal tubes and also the experience with the behavior of metal/plastic tubes under cyclic changes of the surrounding conditions is quite rare. The available experience suggests that a lower degree of expansion retained by the aluminum intermediate layer need not be costless. The composite tube is a very demanding product consisting of two adhesive layers between the plastic and the metal and of a longitudinal weld on the aluminum intermediate layer. Time will show which producers have actually mastered this complex production technology. It is not true for installations that „the newer the better“. What is appreciated is service reliability, proved by years of practice. Unlike all-plastic PE-X tubes, metal/plastic composites have been present on the market for a short time and the majority of them, though under a number of names, are supplied by Chinese producers. Maybe the only advantage of the material is its good shape stability and relatively easy manipulation during installation work. The problem is the jointing. The aluminum layer hinders the full expansion and the memory effect, the tube does not return to original size so that joints need sealing rubber bands.

It is recommended to chose a system whose tightness is not limited by the working life of an additional feature--rubber bands and sealing rings. Why on earth some systems started with one rubber band and now they end up with as many as three of them! Let us believe that this is not an effort to achieve a longer working life of the joint right beyond the guarantee term. In this case, it is also true that practical attestation of reliability is critical. An axial moulded joint (along the tube axis) without rubber bands that takes advantage both of the PE-X shape memory and the material flow under high pressure during moulding is a good example because joints of this type have been used for more than 40 years. This kind of joint has ten times higher stability than the tube itself and its working life is practically unlimited.

There are several all-plastic PE-X systems with axial moulded joint on the market. Your decision depends on whether you prefer famous brand products at double prices or whether you prefer Czech products with similar quality but at a reasonable price. For logical purposes of achieving a profit as high as possible, suppliers tend to offer the most expensive products. Our complete REVEL-PEX System Catalog gives the installation description and the price of each component. It can be downloaded in PDF format directly from the Czech home page.

Guarantee terms are different for each system. REVEL is the only company on the home market which provides full guarantee including potential consequential damage. The guarantee lasts for 25 years and applies both to the tube and to the moulded joint. We export also to Great Britain, Canada and USA.

We have been active on the market for more than 10 years and we will do our best to satisfy YOU CHOSE REVEL-PEX SYSTEM

Ask for REVEL from your designers, implementors and sellers

	http://www.revel-pex.com/ e-mail: info@revel-pex.com

The principle of pipe jointing is very simple and reliable. A sleeve ring is slipped over the plastic tube (1), the tube orifice is mechanically extended for several seconds and before the plastic returns to original shape (original diameter of the tube) a jointing element (2) is pushed on it. The slipped-over ring (3) fixes the joint and causes the joint to remain stable, tight and robust. The jointing takes approximately 10 seconds, no additional jointing or tightening elements (e. g. rubber bands) are necessary. The joint requires no time for drying (no glue) or cooling.

Prices of some elements of REVEL-PEX system and floor fan-coils

Včetně pochůzné mřížky kovové nebo bukové / Delivered with metal ‘or beech grate

Délka L (mm) Výška H (cm)/Šířka B (mm)		800	1200	1600	2000	2400	2800
10/275	Výkon (W)	276	440	597	744	928	1066
	price (CZK)	3098	4190	5289	6365	7444	8525

Včetně pochůzné mřížky a axiálních ventilátorů (12V DC) Delivered with metal or beech grate and axial fan (12V DC)

Včetně pochůzné mřížky a tangenciálních ventilátorů (12V DC) / Delivered with metal or beech grate and tangencial fan (12V DC)