Aluminium multilayer pipes consist of 5 layers, respectively PE-RT plastic, adhesive, aluminium alloy, adhesive, PE-RT plastic. They have the special feature of combining the qualities of metal pipes with those of plastic materials. As plastic materials, SESTA uses two polymers that have high temperature stability characteristics: PEX AND PE-RT.
PE-RT is also known as 'polyethylene with increased thermal resistance': it is guaranteed for 70 °C and 10 bar; it is not suitable for heating systems with radiators (which can also operate at 90 °C), but is fine for all other plumbing and heating applications.