In the photos, maniflods for the transport of domestic hot water in a company in Northern Italy. After years of use, these manifolds showed clear signs of corrosion and had to be replaced with plastic manifolds. There are many advantages of plastics over iron, starting with its lower cost. Light, versatile, resistant, it has low energy consumption and is recyclable. It is used extensively in the construction industry for its ability to resist corrosion. Furthermore, in addition to being easy to handle, it can be molded into any desirable shape, have any color or any physical property. It is suitable for use in seismic areas, has high resistance to abrasion, stray currents and frost conditions and shows low pressure drop.