Non Return Valves Water

return
Come or go back to a place or person
Go back to (a particular state or activity)
tax return: document giving the tax collector information about the taxpayer's tax liability; "his gross income was enough that he had to file a tax return"
Turn one's attention back to (something)
go or come back to place, condition, or activity where one has been before; "return to your native land"; "the professor returned to his teaching position after serving as Dean"
a coming to or returning home; "on his return from Australia we gave him a welcoming party"

valves
(valve) device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
(valve) control consisting of a mechanical device for controlling the flow of a fluid
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
A device for controlling the passage of fluid through a pipe or duct, esp. an automatic device allowing movement in one direction only
(valve) a structure in a hollow organ (like the heart) with a flap to insure one-way flow of fluid through it
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

water
body of water: the part of the earth's surface covered with water (such as a river or lake or ocean); "they invaded our territorial waters"; "they were sitting by the water's edge"
A colorless, transparent, odorless, tasteless liquid that forms the seas, lakes, rivers, and rain and is the basis of the fluids of living organisms
This as supplied to houses or commercial establishments through pipes and taps
One of the four elements in ancient and medieval philosophy and in astrology (considered essential to the nature of the signs Cancer, Scorpio, and Pisces)
binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent
supply with water, as with channels or ditches or streams; "Water the fields"