What is SDR in HDPE Pipes?

HDPE Spiral Profile Pipe basically play an insignificant role in installation, which is neither as changeable as other products, nor as unique as it can be appreciated. However, as an indispensable role in daily use, HDPE pipes play a very important role in creating a healthy and comfortable environment for you. 

Choosing different HDPE Spiral Profile Pipe according to the different pressure in use and the different material of pipeline can greatly improve the utility. 

Generally, there are two kinds: PE100 HDPE pipes and PE80 HDPE pipes, in which PE100 has 20% more compressive capacity than PE80.

Standard Dimension Ratio of PE80 Grade PE HDPE Spiral Profile Pipe: SDR33，SDR21，SDR17，SDR13.6，SDR11；

Standard Dimension Ratio of PE 100 Grade PE HDPE Spiral Profile Pipe: SDR26，SDR21，SDR17，SDR13.6，SDR11.

HDPE Spiral Profile Pipe has medium density polyethylene HDPE pipe and high density polyethylene HDPE pipe. SDR11 and SDR17.6 series are classified according to wall thickness. The former is suitable for transporting artificial gas, natural gas and liquefied petroleum gas, while the latter is mainly used for transporting natural gas. Compared with steel HDPE pipe, the construction technology is simple and flexible. 

More importantly, it is not used as anticorrosive treatment, which will save a lot of working procedures. The disadvantage is that the equipment is inferior to the steel HDPE pipe. Special attention should be paid to the safe distance of thermal heating during construction, and it can not be exposed to the sunshine in the air, and it is sensitive to chemicals, so as to prevent the leakage of sewage pipelines from causing harm.

Standard Size Ratio (SDR): Ratio of nominal diameter DN to nominal wall thickness en of pipe. SDR＝dn/en

The relationship between nominal pressure (PN) and design stress and standard size ratio (MRS) of HDPE pipes is as follows: PN=2σs/(SDR-1) (The units of PN and_s are Mpa)

SDR（standard dimension ratio of a fitting）refers to the standard size ratio of HDPE Spiral Profile Pipe, SDR=2S+1≈de/e, which is the ratio of nominal outer diameter to nominal wall thickness. The larger the value, the smaller the pressure bearing capacity of HDPE pipes, and vice versa.

SDR11 can be understood as the outer diameter of the HDPE Spiral Profile Pipe is 11 times the wall thickness, the value is small, and the bearing capacity is good.

In HDPE pipe, "SDR" indicates the ratio of outside diameter to wall thickness. The bigger the thickness of the pipe wall, the smaller the SDR value and the higher the strength of the pipe. For example, if the outer diameter is 315 mm and the wall thickness is 18.7 mm, the SDR ratio is 17, that is SDR 17.

Generally, SDR17.6 can be sed for micro-pressure and SDR11 for high-pressure. The choice of wall thickness is based on pressure. There are no hard and fast rules, such as PE100 SDR 17.6 pressure bearing capacity and PE80 SDR 11. 

Eagle Machinery Co., Ltd is the professional manufacturer to produce large diameter HDPE/PP spiral profiled pipe production line. We have successfully provided all of the world with profiled pipe production line from DN300mm to DN4000mm and have more than 8 years experience.