Culverts or tunnels

Photo	Location	Tagging	Comments
	USA	outlet=valve valve=gate	A gate is controlling flow through an outlet of a discharge tunnel of Hoover Dam. See it closed below

Pipelines

None of these situations indicates the water reach a water body, so no combination with man_made=outfall is made.

Photo	Location	Tagging	Comments
	France	pipeline=valve outlet=valve valve=hollow_jet	A special kind of pipeline outlet with valves spreading a dense flow of water on a wide area as to reduce downstream damage or erosion You usually find them on large dams
	USA	pipeline=valve outlet=valve valve=hollow_jet	A hollow jet valve provided by Howell-Bunger in operation downstream of a dam
	USA	pipeline=valve outlet=valve valve=needle	A needle valve could also be used to mitigate impact of pressurised output water, here at the bottom of a dam
	-	pipeline=valve outlet=valve valve=check	Such a protection, sometimes called a flap valve, prevents downstream floodwater to get in the underground drain. The flapper of the check valve only moves when upstream flow comes at enough level to raise the movable gate.