REVEL FITTINGS AND AXIAL PRESSED JOINT

The REVEL coupling system is based on utilization of the PE‑X cross-linked polyethylene shape memory, which is partly effective also in composite pipes. The assembly begins with increasing the pipe end diameter using expander but only in such a way to enable the fitting to slide in. This is a very important condition of assembly, the material breach of which (so called over-expansion) represents the most frequent reason for immediate joint leakage caused mostly by well-visible irregular damage of tube end or aluminium inset. This condition is of such an importance that a special expanded head has to be used. It is also very important to expand the pipe in its axis. Chemical composition of the material allows in the course of time subsequent returning of the expanded pipe into original dimension (so called memory effect) resulting in a firm grip of the fitting. Pressing of the safety ring follows accompanied with the pipe material creeping at a very high pressure. This results in a firm connection and perfect tightness of the joint. Tightness is guaranteed even without rubber packing rings and this ensures practically unlimited life of the joint, which shows many times higher strength in comparison to the pipe itself. This system based on the so called „axial pressing“ (in the pipe axis direction) is the oldest method of PEX pipes joining perfectly proven in practice by many companies, which utilizes a double sealing effect (memory and press) mutually reducing the risk of error occurring in either of them. The joint tends to be self-sealing and if it proves to be tight under a pressure test its leakage in the course of time is practically impossible and immediate laying into concrete or wall assembly may be performed. Our correctly executed joints are by far the most solid system elements and are able to reliably resist more than ten times the strength of the pipe itself (including plastic fittings). The REVEL Company supplies a comprehensive assortment of brass and plastic fittings, of which several are designed for two pipe dimensions. The system is supplemented by L- and T-shaped radiator connections made of nickel-plated semi-hard copper pipes of 15×1 mm. Like several other major manufacturers of these items, also the REVEL Company has introduced fittings made of high-quality structural plastic PPSU to the market. From the available assortment of PPSU materials the REVEL Company has chosen the type showing the highest toughness. High toughness guarantees reliable function even under demanding conditions of the usual construction practice. This extreme toughness is compensated by somewhat lower surface hardness (compared with brass). This leads to the fact that a trace is left on the fitting flange when pressing the ring. Compliance with the axial pressing principle ensures the advantage of full compatibility of PPSU components with traditional brass parts and the possibility to use the same assembly tools, because
the future trend shows tendency to PPSU fittings. The REVEL Company has been the only manufacturer in the world so far to find technical solution for the production of radiator connectors, which is performed on the basis of a moulded-in insert and subsequent re-pressing of the ring directly in the manufacturing facility. In spite of this fact, the company decided to newly extend its offer to complete all-brass system to meet the requirements of the customers who have not been convinced of the advantages of plastic fittings and who are willing to pay extra charge. For surface piping of composite pipes brass and nickel-coated fittings are used very often for decorative reasons. However, they are delivered within a few days to order. The system is also completed with brass pressing knee-joints for surface piping. Designation of pressed joints as “non-demountable” is not completely accurate since the joints may be disassembled using hot-air gun and the brass fittings are reusable. Pipes damaged by hot air are cut off. With regard to possible damage by high temperatures it is forbidden to reuse PPSU fittings. In common building practice the bends are replaced in all-plastic piping by reinforcements of elbows, which means lower labour intensity and significant financial savings for contractors and significantly lower pressure losses in systems. Composite pipes do not need the above mentioned reinforcements and they keep their shape after bending. The above mentioned reinforcements are used as a tool during pressing to prevent diameter deformation of the metal-plastic pipe (one ear of the arch is open; the other is used to fix the pipe). Pressing rings for joints of the REVEL-PEX system are made of brass pipe material and each ring is designed solely for a particular pipe dimension and type. Rings provided with chemical nickel are used for composite pipes.

The system is further supplemented with screwed joints and reducers based on Euro-type cones (EK), which ensure tightness by means of both the O-ring and the cone. This offer enables assembly of floor and wall-mounted heating using the REVEL‑PEX system and connecting the pipes on valves of bodies and distributors without pressing and expanding tools. The same EK fittings are used for MP pipes as ell as for PEX pipes. No problems have occurred in respect of reliability of these joints, but despite this fact the company prefers the pressed joint and provides a 25-year guarantee for this joint.