escape valve; release valve; relief valve
Technical term for a valve that allows fluid or gas to escape, often to prevent overpressure. Used in engineering and mechanical contexts.
ボイラーには安全のために逃がし弁が付いている。
The boiler is equipped with a relief valve for safety.
Compound of 逃がし (にがし, 'letting escape', from 逃がす) and 弁 (べん, 'valve').