Control valve

A control valve (1) for regulating a water flow to or from a device in an HVAC system, such as a cooling or heating convector, said control valve comprising:

• a valve body (2),
• a shaft (15,25) rotationally suspended in said valve body (2) with a portion of said shaft (15,25) configured to be coupled to an actuator (180) for rotation about a valve axis X,
• a first, radially directed, port (11,21),
• a second, radially directed, port (12,22), and
• a third, radially directed, port (13,23),
• a first ceramic plate (16,26) and a second ceramic plate (17,27) mounted about said shaft (15,15′,15″) and in intimate contact with each other, the first ceramic plate (16,26) being held stationary against motion about the shaft (15,15′,15″), while the second ceramic plate (17,27) is coupled to the shaft (15,15′,15″) to rotate with the shaft (15,15′,15″) without introducing any rotation of the first ceramic plate (16,26),
• said second ceramic plate (17,27) having one through-going opening or recess (33,43),
• characterized by
• said first ceramic plate (16,26) having a first through-going opening or recess (31,41) and a neighboring second through-going opening or recess (32,42), 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) by the one through-going opening or recess (33,43) overlapping at least partially with said first through-going opening or recess (31,41), and
• to a second range of angular positions in which the second port (12, 22) is in fluid communication with the third port (13, 23) by the one through-going opening or recess (33,43) overlapping at least partially with said second through-going opening or recess (32,42),
• wherein said first range of angular positions does not overlap with said second range of angular positions.