Compression fittings for Alupex tubing - Compression fittings are for connecting Danfoss valves to circuits in heating systems only. When connecting circuits with compression fittings for Alupex tubing, always observe the maximum operating pressure and temperature which are given by the tubing manufacturer. However, 6 bar and 95° C must not be exceeded. One set consists of one olive, one supporting bush, one insulation washer and one union nut