Why are their two markings on the new PE4710 pipe?
ASTM expanded its coding system in ASTM D3350-06 to properly represent the improvements in PE resins to create PE 4710. Pipe producers responded in various ways although most chose to use both the old and new pipe material designation codes on the product where it applies. Some requirements, specifications and regulations reference the older versions of the standard. Pipe meeting these older versions may still carry the PE3408 designation. Most PE pipe will carry dual (PE3408/PE4710) or even triple markings (PE3408/PE4710 – PE100) as long as required by requirements, specifications and regulations.
