DESIGN CONSIDERATION
The flow charts given here have each been calculated for a particular SDR and can therefore be applied various pressure classes depending on the material designation stress. Only sizes covered by SANS/ISO 4427 have been included in these charts.
The nomogram below provides a guide to friction losses that can be expected when using clean HDPE pressure pipes with clean water at 20 oC. No account has been taken of any possible fittings in line.
The table below gives the PN classes (pressure in bar) covered by each SDR.
