A vessel in which high temperatures can be achieved by using high pressure; the domestic pressure cooker is an example.
At atmospheric pressure water boils at 100 °C; at 5 lb (35kPa) above atmospheric pressure the boiling point is 109 °C; at 10 lb (70 kPa), 115 °C; at 15 lb (105 kPa), 121 °C and at 20 lb (140 kPa), 126°C.
Autoclaves have two major uses. In cooking, the higher temperature reduces the time needed. At these higher temperatures and under moist conditions, bacteria are destroyed more rapidly, so permitting sterilisation of foods, surgical dressings and instruments, etc.