Whether different grades of PE pipes — such as PE80 and PE100 — can be butt fused mainly depends on their Melt Flow Rate (MFR).
Under the same heating conditions, PE80 melts faster than PE100.

If the MFR difference exceeds 0.5, butt fusion is not recommended, as uneven melting will cause internal stress and possible cracking over time.

In such cases, electrofusion fittings should be used instead.
They can better adapt to material differences and ensure reliable sealing.

Welping recommends always checking material compatibility before welding to guarantee long-term pipeline safety.