What MRS means
Minimum Required Strength (MRS) is the material’s long-term hydrostatic strength at 20°C over 50 years, expressed in MPa. PE 80 has MRS = 8 MPa. PE 100 has MRS = 10 MPa. Higher MRS = thinner walls for the same pressure.
Wall thickness comparison
For a 200 mm OD PN 10 pipe: PE 80 requires ~18.2 mm wall; PE 100 requires ~14.7 mm. That is a 19 percent material saving — significant on large trunk mains.
Applications
PE 80 remains widely specified for water supply distribution and rural networks. PE 100 is preferred for high-pressure trunk mains, gas distribution and where material cost savings on thick walls are material.
Cost implications
PE 100 raw material costs marginally more per kg. But the thinner wall means less material per metre, so PE 100 pipes are often cost-equivalent or cheaper on a per-metre basis for high PN ratings.
How to choose
Follow the tender specification if given. For new specifications, PE 100 is the modern choice for PN 10 and above trunk mains; PE 80 for PN 6 rural distribution.
