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The use of PE100 RC is, in fact, the optimal solution for the resolution of all the critical aspects linked to the installation, in particular allowing the overcoming of the difficulties related to the risk of damage due to local loads and engraving of the external surface, however, preserving the high mechanical resistance of the polyethylene characteristic (MRS 10 MPa).

The multilayer Renovation VRC® GAS pipe was extruded on a technologically advanced line, whose processing stages are chained together in an automatic management and control system able to continuously supervise the whole process. The constant monitoring of the working temperature through suitable temperature control systems, the cooling parameters and of the degree of vacuum applied during calibration have allowed to obtain a homogeneous temperature profile along the whole section. The online monitoring of the dimensional characteristics of the entire surface of the pipe, by a very reliable ultrasound measuring device, has also enabled to reach the maximum assurance of compliance of the product batch to the dimensional requirements.
The installation of new pipelines and rehabilitation of pipes in the subsurface features often involves costly economic investments and requires action on the environment ever more difficult to sustain. By contrast, some numerical details related to this project give you an immediate idea of the most effective works associated with this kind:

• the laying of approximately 3000 meters of pipeline only took around 20 working days;
• The resulting material conferred to the landfill was a little more than 36 m3 (compared with more than 1,500 estimated in the open trench);
• the filling material (sand and gravel) used amounted to about 40 m3 (compared to 1,600 in the planned open pit excavation);
• restore using bitumen road mantle affected only 75 m2 against the required 6,900 according to the traditional installation.

Therefore, in situations of this kind, today more and more sensitive to the protection of the ecosystem and the reduction of occupational hazards associated with the site, that the laying techniques in work of underground networks can find the support resulting from the evolution in research of innovative materials for the production of piping intended not only to the combustible gas transport, as in the specific case, but also in aqueducts, drains and cable pipelines for telecommunications.

Idrotherm 2000 was selected as the producer of polyethylene pipes in possession of the most suitable processing technology to the production of pipes to be used in this context, thanks to the availability of machinery equipped with automatic controls on the production line, able to ensure uniformity and consistency in the dimensional characteristics and absolute absence of surface defects. The product with the best performance has been identified in a type of bimodal PE80 yellow resin, which combines good processability with excellent mechanical properties (in particular, greater resistance to the onset and to the spreading of brittle cracks). The extrusion of polyethylene pipes with an elevated diameter and thickness, in fact, usually results as a challenge for the tendency to failure on the part of the polymer, i.e. for the propensity of the “particular” material down before the cooling is complete (sagging). Thanks to the experience acquired by Idrotherm 2000 over the years, the construction of the pipe has been accompanied by the overcoming of any kind of difficulty and the product pipe was characterised by very low values of deviation from circularity. At the end of the production phase, the pipe was exposed to a laboratory test cycle (geometric characteristics, of fluidity index in the mass, thermal stability, elongation at break, hydrostatic resistance) the exceeding of which has allowed the initiation of the subsequent stage being installed by AEM.
The positive outcome of the experiment put in place by AEM revealed a substantial lack of complications from the operational point of view, a running speed of the construction similar to that obtainable with more established technologies and above all the low environmental impact, thanks to the characteristics of the raw materials used, encouraging the inclusion of trenchless technologies among those available for any replacements on gas distribution networks.