Valve unit

A valve unit has a fluid housing through which a fluid duct extends from a first opening across a valve seat to a second opening, a valve drive connected to the fluid housing and configured to drive a valve closing body cooperating with the valve seat, the valve closing body coming into contact with the fluid in operation on the face side facing the valve seat and on a side facing away from the valve seat, and a connecting plate having a connecting surface to which the fluid housing can be mounted and in which a fluid supply duct and a fluid outlet duct are formed. The fluid housing is adapted to be mounted to the connecting plate in a first position and in a second position rotated in relation to the first position through 180 degrees relative to an imaginary axis of rotation extending perpendicularly to the connecting surface, wherein during operation of the valve unit, with a direction of flow of the fluid through the connecting plate remaining unchanged, a flow over the seat takes place in the first position and a flow under the seat takes place in the second position.