The autoclaves of Tuttle-type (Cold Seal Pressure Vessel) are thick walled high temperature alloys with blind hole and externally heated by a tube furnace. The wall to hole relationship is around 5:1 the closure nut is located outside the hot zone of the furnace. The autoclaves are pressurized with water (H2O) and used for maximum temperatures of 900°C at 100 MPa, and 800°C at the maximum pressure of 500 MPa. Oxygen fugacity in the interior of watersaturated capsules is controlled at Ni/NiO buffer. Compressed air is applied for the cooling device of the autoclaves.
The H2O-CSPV’s can be used for experiments at high pressure and temperature under oxidizing conditions, e.g., to simulate hydrothermal and magmatic processes in the Earth’s crust and in the upper mantle. Hydrothermal synthesis of minerals may be possible as well.
Tuttle, O. F. (1949): Two Pressure Vessels for Silicate-Water Studies. Geological Society of American Bulletin 60, pp. 1727-1729
Ulmer, G. C., Barnes, H. L. (1987): Hydrothermal experimental techniques. New York: John Wiley & Sons