noun
vapor pressure; steam pressure
Technical term used in physics, chemistry, and engineering. In everyday contexts, often refers to the pressure of steam in boilers or cooking appliances.
水の蒸気圧は温度が上がると高くなる。
The vapor pressure of water increases as the temperature rises.
この鍋は蒸気圧を利用して短時間で調理できる。
This pot can cook in a short time by using steam pressure.
気圧 means 'atmospheric pressure', whereas 蒸気圧 is the pressure of a specific vapor, not the ambient air.
Compound of 蒸気 (jōki, 'steam, vapor') and 圧 (atsu, 'pressure'). The reading is the standard on'yomi for each kanji.