Explanation of Material / SDR Relationship


Ningbo Fangli Technology Co., Ltd. is a mechanical equipment manufacturer with nearly 30 years’ experiences of plastic pipe extrusion equipment, new environmental protection and new materials equipment. Since its establishment Fangli has been developed based on user’s demands. Through continuous improvement, independent R&D on the core technology and digestion & absorption of advanced technology and other means, we have developed PVC pipe extrusion line, PP-R pipe extrusion line, PE water supply / gas pipe extrusion line, which was recommended by the Chinese Ministry of Construction to replace imported products. We have gained the title of “First-class Brand in Zhejiang Province”.

The pressure rating of pipe (PN) is determined by the diameter, wall thickness, and material types and is expressed as: 


PN – Pressure pipe rating at 20°C (MPa x 10)


The basic polyethylene (PE) material types used for pipe production are PE63, PE80 and PE100, the number indicating long term strength. 


The term SDR, Standard Dimension Ration, is introduced to describe the pipe, in combination with the material type. 


The higher the SDR, the thinner the pipe, and the lower the pressure rating. 

AS/NZS 4130 uses a standard SDR series, in combination with the three material types, to provide standard pipe pressure ratings as shown in the table.


The field conditions under which poly pipe is welded have a considerable effect on the strength of the joint. Any contamination of the weld, whether it be oxidised polyethylene, water, dust, oils etc can ruin joints.

If you need more information, Ningbo Fangli Technology Co., Ltd. welcomes you to contact for a detailed inquiry, we will provide you with professional technical guidance or equipment procurement suggestions.


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