US Patent No. 9,228,670

SOIL MOISTURE RESPONSIVE IRRIGATION FLOW CONTROL VALVE


Patent No. 9,228,670
Issue Date January 05, 2016 
Title Soil Moisture Responsive Irrigation Flow Control Valve
Inventorship Glendale Grizzle, Murrieta, CA (US)
Assignee Hunter Industries, Inc., San Marcos, CA (US)

Claim of US Patent No. 9,228,670

1. A drip irrigation system, comprising:
an irrigation controller;
a plurality of solenoid actuated valves electrically connected to the irrigation controller and hydraulically coupled to a
source of pressurized water;

a plurality of moisture responsive flow control valves buried in the soil in different landscape zones, each moisture responsive
flow control valve comprising a hygroscopic element configured to expand and shut off water flow through the moisture responsive
flow control valve upon absorption of a predetermined amount of moisture;

a plurality of sets of drip emitters, each set of drip emitters being connected to a corresponding one of the plurality of
moisture responsive flow control valves; and

each of the plurality of moisture responsive flow control valves connected to a corresponding one of a plurality of branch
lines of drip tubing, each branch line being connected to a corresponding one of the solenoid actuated valves;

wherein one or more of the moisture responsive control valves include:
a valve chamber in fluid communication with a water inlet of the moisture responsive control valve; and
a flow control disc having positioned in the valve chamber, the flow control disc comprising:
an outer periphery;
a first side facing the water inlet;
a second side facing away from the water inlet;
a recess in the second side through which water can bypass the flow control disc; and
one or more notches in the outer periphery, the one or more notches forming one or more fluid flow paths between the water
inlet and the recess.