Assertion: valve | /r/CapableOf | drop to obstruct fluid
Facets:
value: to obstruct gas
type: PURPOSE
Source sentences:
text: The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction.
text: The simplest, and very ancient, valve is simply a freely hinged flap which drops to obstruct fluid (gas or liquid) flow in one direction, but is pushed open by flow in the opposite direction.