Asco Valve

valve
A membranous fold in a hollow organ or tubular structure, such as a blood vessel or the digestive tract, that maintains the flow of the contents in one direction by closing in response to any pressure from reverse flow
control consisting of a mechanical device for controlling the flow of a fluid
device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
A device for controlling the passage of fluid through a pipe or duct, esp. an automatic device allowing movement in one direction only
A cylindrical mechanism in a brass instrument that, when depressed or turned, admits air into different sections of tubing and so extends the range of available notes
a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it

asco
Services Canteens Organisation (Australian Canteen Service)
Asco is a large village in the comarca of Ribera d'Ebre, Catalonia, Spain, on the right bank of the Ebro river. The village of Asco is known for its nuclear power station, and for excellent fishing in the river.
American Society of Clinical Oncology, a professional society.