What is sdr in hdpe pipe?

December 21, 2023
The SDR pipe is the "Standard Dimensional Ratio" and refers to the geometry of the pipe. SDR is defined as the ratio of the nominal outside diameter to the nominal wall thickness. The SDR value of Polyethylene Pipe is the main factor in determining the resistance of the pipe against the forces during installation and work pressure.
SDR = D/S
What is sdr in hdpe pipe
Definition of SDR with an example
For example, SDR11 means that the outer diameter of the PE pipe is 11 times of the wall thickness. As a result, the higher the SDR, the
SDR
lower the pipe pressure will be. The details are discussed below.
For PE pipes, a dimensionless number is also defined, which is the ratio of the pipe diameter to the thickness of the pipe, which is referred to as the SDR. For example, for a 110 mm PE pipe with a pressure of 4 times made of PE80 materials, weighing 1.17 kg, it is SDR33, and for an PE pipe with a diameter of 110 mm made of PE80, weighting 1.77 kg, it is SDR21. Therefore, for a 110 mm diameter pipe, SDR decreases as the thickness increases due to the constant diameter (leading to increased pressure). SDRs range from 5 to 51, and the smaller the SDR is, the greater the pipe thickness and the lower pipe diameter will be.
 
What SDR means
Standard Dimension Ratio or SDR describes a pipe's geometry, it is simply the ratio of outer diameter of the pipe to its wall thickness. As an example, a pipe with SDR11 has an outer diameter that is 11 times its wall thickness. Therefore, if the outer diameter or OD of the pressure pipe is known, then the wall thickness can be calculated for any given SDR number.
 
The Higher the SDR number the thinner the pipe wall is in relation to its Outer Diameter.
The Lower the SDR number the thicker the pipe wall will be in relation to its Outer Diameter.