Metal and plastic transition joints

Metal and plastic transition joints

Thanks to new technologies and specific standards (Italian Ministerial Decree [D.M.] of 16 November 1984 and the subsequent revision of 24 November 1999), water and gas, freely-flowing or under pressure, are no longer circulated in steel or cast iron pipes, but are  distributed through highdensity polyethylene (HDPE) pipelines. Polyethylene (PE) is a synthetic material particularly suitable for these purposes. Its strength, flexibility and versatility make it ideal for a wide variety of uses. In a sense, this has led to a revolution. In the costs, for a start: PE is a far more economical raw material than steel, both to purchase and to install. Moreover, it makes it easier to manage subsequent system maintenance. PE piping is generally connected using one of three methods. The first is by welding (PE to PE) with the aid of an electric bush: this jointing method is very simple and effective, assuring a solid and absolutely air- and water-tight connection.The second is by end-to-end welding (PE to PE). The third involves the use of fittings, which are tightened in place so that the end of the pipes provide a hermetic seal. This last method is used for jointing between PE and PE, or between PE and metal. While the first two systems involve melting the material and consequently ensure a homogeneity of the material, the third can suffer from dripping, leaks or structural settlement in the ground, thermal dilation of the metals, and so on. That is why such joints must always be readily accessible for inspection, so they are placed inside a pit on ground level. It is so important to ensure the safety of these systems that action has been taken in some countries to establish precise standards on transition and/or connection systems in order to ensure the homogeneity of the connection. The use of transition joints is, in this sense, a guarantee of tightness, since the joint cannot be manhandled and it can be laid underground, thus making it easier and cheaper to install the system. The tightness of the joint is checked during the construction stages.
Boldrin Group distributes a complete range of transition joints specifically for gas and water pipelines with the following features:
- straight and/or elbow sections for nominal pressures of PN10 and/or PN 16 including
fire-fighting applications
- in the flanged version/type usable on the fire hydrant
- with flanged valves (this means that the system can be certified by the manufacturer/servicing technician).

Products of this category: