Irrigation Pressure Reducing Valve

pressure reducing
(Pressure Reduction) Reduction of interface pressure, not necessarily below the level required to close capillaries (i.e., capillary-closing pressure).

irrigation
supplying dry land with water by means of ditches etc
(irrigate) supply with a constant flow or sprinkling of some liquid, for the purpose of cooling, cleansing, or disinfecting; "irrigate the wound"
(medicine) cleaning a wound or body organ by flushing or washing out with water or a medicated solution

valve
A device for controlling the passage of fluid through a pipe or duct, esp. an automatic device allowing movement in one direction only
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 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
device in a brass wind instrument for varying the length of the air column to alter the pitch of a tone
control consisting of a mechanical device for controlling the flow of a fluid