What is the difference between HDPE and Plastic Compression Fittings?
Temperature range. While both plastics are relatively heat-resistant, HDPE has a higher melting point than most at 160ºF. HDPE plastics also have a lower cold brittleness temperature than PET plastics, resisting cold up to -50ºF, while PET plastics can only handle temperatures as low as -40ºF.
Many, but not all, compression fittings are suitable for use with plastic fittings and pipe. Users should therefore check for compatibility. Compression fittings with short tube stop depth or hard olives should not be used with plastic fittings or pipe.