Control valve
A control valve ( 1 ) for regulating a water flow to or from a device in a HVAC system, having a valve body ( 2 ), a shaft ( 15,25 ) rotatable about a valve axis X, a first ceramic plate ( 16,26 ) and a second ceramic plate ( 17,27 ) mounted about the shaft ( 15, 15′, 15″ ), the first ceramic plate ( 16,26 ) being stationary, while the second ceramic plate ( 17,27 ) is coupled to the shaft ( 15, 15′, 15″ ) to rotate with the shaft ( 15, 15′, 15″ ), the first ceramic plate ( 16,26 ) having first- and second through-going openings ( 31, 32, 41, 42 ), the second ceramic plate ( 17,27 ) having one through-going opening or recess ( 33,43 ), first-, second- and third, ports ( 11, 21, 12, 22, 13, 23 ), wherein the second ceramic plate ( 17, 27 ) is rotatable: to a first range of angular positions in which the first port ( 11, 21 ) is in fluid communication with the third port ( 13, 23 ), and to a second, different range of angular positions in which the second port ( 12, 22 ) is in fluid communication with the third port ( 13, 23 ).
1 . A control valve for selectively regulating a fluid flow to a device, such as a heating or cooling convector, said control valve comprising:
a first inlet adapted to be connected to a first fluid source;
a second inlet adapted to be connected to a second fluid source,
an outlet adapted to be connected to the device;
an inlet selection element arranged downstream of the first and the second inlets and upstream of the outlet,
a regulator cavity adapted to accommodate a differential pressure regulator, said regulator cavity being arranged downstream of the inlet selection element and upstream of the outlet,
wherein said inlet selection element is moveable between:
a first position in which the first inlet is in fluid communication with a first location in the regulator cavity, and
a second position in which the second inlet is in fluid communication with the first location in the regulator cavity,
wherein said inlet selection element comprises a first ceramic plate and a second ceramic plate mounted about a rotatable shaft, the second ceramic plate being in intimate contact with the first ceramic plate, the first ceramic plate being held stationary against motion about the shaft, while the second ceramic plate is coupled to the shaft to rotate with the shaft without introducing any rotation of the first ceramic plate,
a fourth fluid passage in fluid communication with a second location in the regulator cavity,
wherein the fourth fluid passage is in fluid communication with the first inlet when the inlet selection element is in said first position, and
wherein the fourth fluid passage is in fluid communication with the second inlet when the inlet selection element is in said second position,
wherein the second ceramic plate is movable:
to a first range of angular positions in which the first inlet is in fluid communication with the outlet, and
to a second range of angular positions in which the second inlet is in fluid communication with the outlet, wherein said first range of angular positions does not overlap with said second range of angular positions,
whereby, when a differential pressure regulator is located in said regulator cavity 90 , constant differential pressure can be maintained across said inlet selection element.
2 . The control valve according to claim 1 , wherein said first ceramic plate has a first through-going opening or recess and a second through-going opening or recess, and said second ceramic plate has one through-going opening or recess.
3 . The control valve according to claim 1 , wherein said first- and second ceramic plates are fluidically arranged between said first inlet and said outlet and said first- and second ceramic plates are fluidically arranged between said second inlet and said outlet.
4 . The control valve according to claim 1 wherein said first opening or recess in the first ceramic plate at least partially overlaps said one opening or recess in said second ceramic plate in a first range of angular positions of said second ceramic plate for fluidically connecting said first port to said outlet, and
said second opening or recess in the first ceramic plate being at least partially aligned with said one opening or recess in said second ceramic plate in a second range of angular positions of said second ceramic plate for fluidically connecting said second port to said outlet.
5 . The control valve according to claim 1 , comprising a differential pressure regulator arranged in said regulator cavity.
6 . The control valve according to claim 1 , comprising a fourth fluid passage in fluid communication with the regulator cavity or with a regulator outlet.
7 . The control valve of claim 6 , further comprising a pressure selector, wherein said pressure selector is moveable between a first selection position, which establishes fluid communication between a first fluid passage and the fourth fluid passage, and a second selection position, which establishes fluid communication between a second fluid passage and the fourth fluid passage.
8 . The control valve according to claim 7 , wherein the pressure selector is operably connected to the inlet selection element such that the pressure selector is moved to said first selection position when the inlet selection element connects the first inlet to the outlet and such that the pressure selector moved to said second selection position when the inlet selection element connects the second inlet to the outlet.
9 . The control valve according to claim 7 , wherein the pressure selector comprises a ceramic selector plate having a side that engages a surface of said first- or second ceramic plate for establishing intimate contact therebetween.
10 . The control valve according to claim 9 , comprising an arrangement configured for moving said ceramic selector plate to a first selection position when said second ceramic plate is in said first range of angular positions and to a second selection position when said second ceramic plate is in said second range of angular positions.
11 . The control valve according to claim 10 , wherein said ceramic selector plate establishes fluid communication between the first fluid passage and the third fluid passage when it is in said first selection position and establishes fluid communication between a second fluid passage and the third fluid passage when it is in said second selection position.
12 . The control valve according to claim 10 , wherein said ceramic selector plate is slidably movable relative to the first- or second ceramic plate that it engages.
13 . The control valve according to claim 8 , wherein the movement of said ceramic selector plate relative to the first- or second ceramic plate that it is in intimate contact with is guided by a recess in and/or projections on said first- or second ceramic plate that it confronts and engages.
14 . The control valve according to claim 10 , wherein said ceramic selector plate is at least partially received in a recess in said first- or second ceramic plate.
15 . The control valve according to claim 14 , wherein said ceramic selector plate is a ceramic selection disc rotatably received in said recess in said first ceramic plate.
16 . The control valve according to claim 15 , wherein said ceramic selector disc at least partially protrudes radially from said recess.
17 . The control valve, according to claim 15 , comprising an abutment member arranged to impart rotation on said ceramic selector disc relative to said first ceramic plate when said second ceramic plate changes between said first range of angular positions and said second range of angular positions.
18 . The control valve, according to claim 17 , wherein said ceramic selector disc comprises a recess or a projection for engaging said abutment member.
19 . The control valve, according to claim 17 , wherein said abutment member comprises a peg connected to said second ceramic plate to move in unison with said second ceramic plate, said peg being partially accommodated in a bore in said second ceramic plate, said peg extending axially from said second ceramic plate in the direction towards said first ceramic plate.
20 . The control valve, according to claim 9 , wherein said ceramic selector plate comprises a cavity, said cavity enabling fluidic connection between said first opening or recess and said a fourth fluid passage in said first selection position and enabling a fluid connection between said second opening and a fourth fluid passage in said second selection position.