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2026-11-10T09:16:17

HDPE Pipe SDR Explained: Is SDR 11 PN16? PE100 Wall Thickness

HDPE管SDR是什么意思：SDR11等于PN16吗？PE100壁厚与公式

The HDPE pipe SDR number is not a brand code but the ratio of outside diameter to wall thickness: the higher the SDR, the thinner the wall and the lower the working pressure. For PE100 water pipe with a design coefficient of 1.25, SDR 11 gives a maximum operating pressure of 16 bar (PN16), SDR 17 gives PN10 and SDR 21 gives PN8. This guide combines the PE100+ Association formula, the Rucika Black variant list and Finnlon's wall-thickness table based on ISO 4427-2 and SNI 4829.2-2015, so buyers can match pipe markings to project needs.

Key Facts

The HDPE pipe SDR formula and how it links to PN

The PE100+ Association defines SDR (Standard Dimension Ratio) as the nominal outside diameter divided by the nominal minimum wall thickness. A 110 mm pipe with a 10 mm wall is therefore SDR 11. The link between SDR and pressure comes from Lamé's formula for hoop stress in thick-walled cylinders. The end result is simple: MOP in bar equals 20 times MRS divided by the design coefficient C multiplied by (SDR − 1). MRS is the material's minimum long-term strength; for PE100 it is 10 MPa, and for water applications the minimum recommended C is 1.25.

Plugging those in, SDR 11 gives 20 × 10 ÷ (1.25 × 10) = 16 bar. In the same way SDR 17 gives 10 bar, SDR 21 gives 8 bar, SDR 9 gives 20 bar and SDR 26 about 6.4 bar, rounded to the PN6 class. Dividing an MRS of 10 MPa by a C of 1.25 gives a design stress of 8 MPa—the same "8 MPa design stress" Rucika lists for Rucika Black. So when a catalogue says PE100 SDR 11 PN16, the three labels lock together; changing the material or the design coefficient changes the PN even at the same SDR.

SDR and PN variants on the Indonesian market

Rucika's price and size page (published 22 August 2025) lists six pressure variants for Rucika Black: SDR 9/PN20 for 75–630 mm diameters, SDR 11/PN16 for 20–630 mm, SDR 13.6/PN12.5 for 50–710 mm, SDR 17/PN10 for 50–630 mm, SDR 21/PN8 for 63–710 mm and SDR 26/PN6 for 90–710 mm. The page gives no unit prices; Rucika asks buyers to contact it directly. Note that the small diameters exist only in SDR 11: 20–40 mm house-connection pipe is in practice always SDR 11/PN16.

Finnlon, a Medan manufacturer, publishes a PE 100 size table referencing ISO 4427-2:2007 and SNI 4829.2-2015. For example, a 63 mm pipe has a 3.0 mm wall at SDR 21, 3.8 mm at SDR 17, 4.7 mm at SDR 13.6 and 5.8 mm at SDR 11. A 32 mm SDR 11 pipe has a 3.0 mm wall and a 20 mm SDR 11 pipe 2.0 mm. Delivery lengths differ too: 20–25 mm sizes come in 200–400 m coils, while 125 mm and up come as 6–12 m lengths.

How to choose an HDPE pipe SDR for a project

Start from the network's working pressure, not the diameter. If pumps and terrain produce a peak of about 8 bar, PN10 (SDR 17) leaves headroom, while PN8 (SDR 21) sits right at the limit. For networks prone to pressure surges designers usually step up a class, but the final choice follows hydraulic calculations and the owner's specification. Remember too that a lower SDR means a thicker wall, a smaller bore and more weight per metre.

The jointing method matters as well. Rucika recommends mechanical-joint fittings (polypropylene, BS 5114) for 20–63 mm, butt fusion above 63 mm and electrofusion for repairs. In butt fusion both ends must share the same SDR so the walls meet flush. homeX can help compile the SDR, PN and diameter list from working drawings before you ask distributors for quotes.

Check the markings when pipe arrives on site

Before accepting a delivery, match the print on the pipe body with the order: material (PE100), SDR, PN, outside diameter and the reference standard. Measure the outside diameter with a circumference tape or caliper; Finnlon's table gives limits, for example 110.0–111.0 mm for a 110 mm pipe. Measure wall thickness at a cut end and compare it with the SDR ordered. SDR 17 pipe delivered in place of SDR 11 is easy to spot: 6.6 mm versus 10.0 mm at 110 mm. Rucika also cites drinking-water certification under Health Ministry Regulation No. 2 of 2023 for Rucika Black; ask for that document if the pipe will carry drinking water.

HDPE pipe SDR: related articles and products

FAQ

Is SDR 11 always PN16? Only for PE100 with a 1.25 design coefficient in water service. The PE100+ formula gives 16 bar for that combination; another material or coefficient gives a different PN even at SDR 11.

How thick is a 110 mm HDPE pipe? Per Finnlon's PE 100 table: 5.3 mm (SDR 21/PN8), 6.6 mm (SDR 17/PN10), 8.1 mm (SDR 13.6/PN12.5) and 10.0 mm (SDR 11/PN16).

Which joint for a 50 mm HDPE pipe? Rucika recommends mechanical joints for 20–63 mm, butt fusion above 63 mm and electrofusion for repairs.

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Sources: PE100+ Association: What is SDR pipe & pressure rating; Rucika: HDPE pipe price and size list (22 Aug 2025); Rucika: Rucika Black product page; Finnlon: PE 100 HDPE pipe, ISO 4427-2 / SNI 4829.2-2015