HDPE PN and SDR Ratings Explained: Pressure Classes for PE100 Pipe

Standard: PN / SDR ratings (PE100 HDPE) · HDPE PE100 pressure pipe (Hansen)

What PN means

PN (“pressure nominal”) is the pipe’s rated continuous internal pressure in bar at the reference temperature. A PN16 pipe is designed for 16 bar; a PN12.5 pipe for 12.5 bar. It is the number the water authority’s schedule and your pump/pressure calculations both care about — not the price per metre. Ratings de-rate at higher fluid temperatures.

What SDR means, and how it sets the wall

SDR (“standard dimension ratio”) is the outside diameter divided by the wall thickness: SDR = OD ÷ e. Because HDPE pipe is sized by outside diameter, a given OD can be made in several wall thicknesses — and SDR is how the standard names them. Lower SDR = thicker wall = higher pressure rating.

The common pairings for PE100 pressure pipe:

PN	SDR	Wall (relative)	Rated pressure
PN10	SDR17	Thinner	10 bar
PN12.5	SDR13.6	Thicker	12.5 bar
PN16	SDR11	Thicker still	16 bar

So “PN16 SDR11”, “PN12.5 SDR13.6”, and “PN10 SDR17” are the same idea stated two ways — the PN is the pressure, the SDR is the geometry that delivers it.

How to read a dimension table

An HDPE dimension table gives, per outside diameter, the SDR, the PN, and the minimum/maximum wall thickness and weight. To use it: pick the PN your design pressure requires, find the OD you are laying, and read the wall thickness the matching SDR row gives you. That wall thickness — not the OD — is what you check against the authority’s minimum and what the fittings must match.

PN12.5 vs PN16 in Malaysian practice

On Malaysian distribution reticulation, PN12.5/SDR13.6 is commonly accepted for standard buried mains; PN16/SDR11 is specified where operating pressure is higher, cover is shallower, or the consultant wants the extra surge margin. The full selection logic — surge, derating, authority acceptance, and a worked example — is in the PN12.5 vs PN16 guide.

Material grade: PE100 vs PE80

PE100 and PE80 are material grades, not pressure classes. PE100 has a minimum required strength of 10.0 MPa, so a thinner wall carries the same pressure as a thicker PE80 pipe. That also means the SDR-to-PN pairings differ between the two grades — on PE80, PN16 is SDR9 and PN12.5 is SDR11, not the SDR11/SDR13.6 used on PE100. Confirm the material grade before reading SDR from a drawing.

What to confirm before you order

For the published PE100 dimensions by OD, SDR, and PN, see the HDPE PN dimension table, then send your schedule for a quotation.