... -HHIn petroleum and natural gas extraction, a Christmas tree is an assembly of valves, spools, and fittings ... and other types of wells.1.X-mass tree is according API 6A2.Working pressure:2000-20000psi3. ... tubing head and the flange.8.The Christmas tree could be assembled differently so as to meet ... the different requirements.9.The Christmas tree could be used for oil exploration, gas exploration ...