[butterfly valve] n (1846) 1: a valve consisting of two semicircular clappers hinged to a cross rib that permits fluid flow in only one direction
2: a damper or valve in a pipe consisting of a disk turning on a diametral axis
[butterfly valve] n (1846) 1: a valve consisting of two semicircular clappers hinged to a cross rib that permits fluid flow in only one direction
2: a damper or valve in a pipe consisting of a disk turning on a diametral axis
Merriam-Webster English vocab. Английский словарь Merriam Webster. 2012