Hot water mixing valve
A mixing valve including a body having first and second inlets, an outlet, and a mixing chamber. A first valve seat is located between the first inlet and the mixing chamber, and a second valve seat is located between the second inlet and the mixing chamber. A shuttle is moveable in the mixing chamber between the first and second valve seats and includes a first plug facing the first valve seat and a second plug facing the second valve seat. The plugs have trim surfaces that are one of, or a combination of, a fast-opening shape, a linear shape, and an equal percentage shape.
1 . A valve comprising:
a body having,
a first inlet and a second inlet,
an outlet,
a mixing chamber,
a first passageway connecting the first inlet to the mixing chamber, and a second passageway connecting the second inlet to the mixing chamber,
a third passageway connecting the mixing chamber to the outlet,
a first valve seat located between the first passageway and the mixing chamber, and
a second valve seat located between the second passageway and the mixing chamber; and
a shuttle located in the mixing chamber and movable between the first and second valve seats, from a first position where the shuttle contacts the first valve seat to block fluid flow at least partially from the first passageway into the mixing chamber and a second position where the shuttle contacts the second valve seat to block fluid flow at least partially from the second passageway into the mixing chamber,
wherein the body further comprises:
a central conduit extending between first and second open ends, the central conduit defining the mixing chamber,
a first sleeve insert received in the first open end of the central conduit and partially defining the first passageway, an end of the first sleeve insert defining the first valve seat,
a second sleeve insert received in the second open end of the central conduit and partially defining the second passageway, an end of the second sleeve insert defining the second valve seat,
a first end cap closing the first open end of the central conduit and defining a bore,
a second end cap closing the second open end of the central conduit and defining a bore,
wherein the shuttle further comprises a stem having a first end and a second end, and a first plugs and a second plug are located on the stem, and
wherein the first end of the stem is slidingly received in the bore of the first end cap and the second end of the stem is slidingly received in the bore of the second end cap.
2 . The valve according to claim 1 , wherein the first plug and the second plug each include a trim surface, and the trim surfaces have an equal percentage shape.
3 . The valve according to claim 1 , wherein the first plug and the second plug each include a trim surface, and the trim surfaces have the same shape.
4 . The valve according to claim 1 , wherein the first plug and the second plug are separate pieces.
5 . The valve according to claim 1 , wherein the first plug and the second plug are separate pieces and are secured such that proximal ends of the plugs touch.
6 . The valve according to claim 1 , wherein the first plug and the second plug are unitarily formed as a single piece.
7 . The valve according to claim 1 , wherein the first plug includes a radially extending flange at the proximal end for contacting the first valve seat when the shuttle is in the first position, and the second plug includes a radially extending flange at the proximal end of the second plug for contacting the second valve seat when the shuttle is in the second position.
8 . The valve according to claim 1 , wherein when the shuttle is in the first position the shuttle fully blocks fluid flow from the first passageway into the mixing chamber and when the shuttle is in the second position the shuttle fully blocks fluid flow from the second passageway into the mixing chamber.
9 . The valve according to claim 1 , wherein when the shuttle is equally positioned between the valve seats a flow from the first passageway into the mixing chamber and a flow from the second passageway into the mixing chamber are equal.
10 . The valve according to claim 1 , wherein the shuttle further comprises a stem having a first end and a second end, and the first plug and the second plug are located on the stem.
11 . The valve assembly including the valve according to claim 1 , further comprising an actuator secured to one of the ends of the stem of the shuttle.
12 . The valve assembly according to claim 11 , wherein the actuator includes a stepper motor.
13 . The valve assembly according to claim 11 , further comprising,
a temperature sensor located in the third passageway, and
a controller connected to the temperature sensor and the actuator and programmed to instruct the actuator to move the shuttle based at least in part on data received by the controller from the temperature sensor.
14 . The valve according to claim 13 , wherein the controller is programmed to slow the speed of the actuator as the shuttle approaches the first and the second valve seats.
15 . A valve station including the valve assembly according to claim 11 , and further comprising:
a cold water conduit connected to the first inlet of the valve;
a hot water conduit connected to the second inlet of the valve;
a mixed water conduit connected to the outlet of the valve;
shut-off valves located in the cold water, the hot water and the mixed water conduits; and
a frame supporting the conduits and the valve assembly.
16 . The valve station according to claim 15 , further comprising a recirculation water conduit supported by the frame, wherein a diversion conduit is connected between the recirculation water conduit and the cold water conduit.
17 . The valve according to claim 1 , wherein the body further comprises,
a first leg connected to the central conduit and defining the first inlet and partially defining the first passageway,
a second leg connected to the central conduit and defining the second inlet and partially defining the second passageway, and
a third leg connected to the central conduit and defining the outlet and the third passageway,
wherein the legs extend substantially perpendicular to the central conduit.
18 . The valve according to claim 1 , further comprising check valves located in the first and the second passageways for preventing reverse flow out of the first and the second inlets.
19 . A valve comprising:
a mixing chamber having two inlets and an outlet, a first valve seat located between the first inlet and the mixing chamber, and a second valve seat located between the second inlet and the mixing chamber;
a first passageway connecting the first inlet to the mixing chamber and a second passageway connecting the second inlet to the mixing chamber; and
a shuttle assembly located in the mixing chamber and movable between the two inlets, from a first position where the shuttle blocks fluid flow at least partially from the first inlet into the mixing chamber and a second position where the shuttle blocks fluid flow at least partially from the second inlet into the mixing chamber, the shuttle including:
a first plug facing the first valve seat, the first plug having a trim surface extending between a distal end and a proximal end, the proximal end being spaced further from the first valve seat than the distal end, wherein the trim surface includes at least one concave section and at least one convex section between the distal and proximal ends, and
a second plug facing the second valve seat, the second plug having a trim surface extending between a distal end and a proximal end, the proximal end of the second plug being spaced further from the second valve seat than the distal end of the second plug, wherein the trim surface includes at least one concave section and at least one convex section between the distal and proximal ends,
wherein the at least one concave section and the at least one convex section of the trim surface of each of the first plug and the second plug collectively define a non-linear metering profile such that axial displacement of the shuttle produces a non-linear relationship between shuttle position and flow rate into the mixing chamber.
20 . The valve of claim 19 , wherein the mixing chamber comprises:
a central conduit extending between first and second open ends,
a first sleeve insert received in the first open end of the central conduit and partially defining the first passageway, an end of the first sleeve insert defining the first valve seat,
a second sleeve insert received in the second open end of the central conduit and partially defining the second passageway, an end of the second sleeve insert defining the second valve seat, a first end cap closing the first open end of the central conduit and defining a bore, and
a second end cap closing the second open end of the central conduit and defining a bore.
21 . A mixing valve comprising:
a chamber having:
a first and second inlet;
an outlet;
a first and second passageway connecting the first and second inlet to the chamber; and
a first valve seat located between the first passageway and the chamber, and a second valve seat located between the second passageway and the chamber; and
a shuttle assembly having:
a first plug facing the first valve seat, an outer diameter of the first plug being larger at a proximal end than at a distal end such that the first plug has a tapered profile, and
a second plug facing the second valve seat, an outer diameter of the second plug being larger at a proximal end than at a distal end of the second plug such that the second plug has a tapered profile,
wherein the proximal end of the first plug and the proximal end of the second plug define opposing proximal faces that directly contact one another to form a common interface, the tapered profile of the first plug extending in a first axial direction from the common interface and the tapered profile of the second plug extending in an opposite axial direction from the common interface, the shuttle assembly being axially displaceable to produce a non-linear relationship between shuttle position and flow rate of fluid from the first and second passageways into the chamber, wherein the shuttle assembly is configured to:
in a first position, contact the first valve seat via the distal end of the first plug to block fluid flow at least partially from the first passageway into the chamber; and
in a second position, contact the second valve seat via the distal end of the second plug to block fluid flow at least partially from the second passageway into the chamber.
22 . The mixing valve of claim 21 , wherein the shuttle assembly further comprises a stem having a first end and a second end, the plugs being located on the stem, the first end of the stem slidingly received in a bore of a first end cap closing the chamber and the second end of the stem slidingly received in a bore of a second end cap closing the chamber.
23 . The mixing valve of claim 21 , wherein the chamber comprises:
a central conduit extending between first and second open ends,
a first sleeve insert received in the first open end of the central conduit and partially defining the first passageway, an end of the first sleeve insert defining the first valve seat,
a second sleeve insert received in the second open end of the central conduit and partially defining the second passageway, an end of the second sleeve insert defining the second valve seat, a first end cap closing the first open end of the central conduit and defining a bore, and
a second end cap closing the second open end of the central conduit and defining a bore.