We reinforced pipe basic material is polypropylene, which bears the primary burden to the temperature and pressure. Outside these tubes are reinforced with aluminum foil thickness 0.15 mm and covered with a protective layer of polypropylene (PEX). The main objective of the foil – to prevent lengthening of the tube during heating. The fact that the plastic pipe due to thermal effects tend to increase in length by 0,5 – 1,5% of the original length. Here is a formula by which we can calculate the linear thermal elongation:
?L = a × L × ? t,
where:
L – linear temperature elongation (m);
a – coefficient of thermal linear extension tube (mm / m × ° C);
L – length of the straight section (m);
t – change the coolant temperature ° C.
* For reference, we present data of the coefficient a:
- For polypropylene – 0,15 mm / m × ° C;
- For cross-linked PEX – 0,15 mm / m × ° C;
- For metal plastic – 0,025 mm / m × ° C.
