A gate valve for controlling a flow of a fluid, the gate valve comprising: a plate-shaped valve housing comprising two plate-shaped valve housing halves (20a, 20b), the valve housing circumscribing a flow opening extending between two major surfaces (21, 22) of the valve housing; a first pipe connected to a first of the two major surfaces (21, 22) to circumscribe the flow opening at the first major surface and a second pipe connected to a second of the two major surfaces (21, 22) to circumscribe the flow opening at the second major surface; and a gate plate slideable within the valve housing between a closed position, in which the gate plate blocks the flow opening, and an open position, which allows fluid flow through the flow opening; wherein the valve housing comprises a circumferential sealing groove, the sealing groove at least partially circumscribing the flow opening, the gate plate sliding in the sealing groove when sliding between the open position and the closed position, the sealing groove comprising two opposed surfaces, two opposed circumferential sealing members each extending from one of the two opposed surfaces to abut an associated one of two major surfaces of the gate plate for sealing the flow opening at least in the closed position; and wherein a protrusion extends from one of the two opposed surfaces of the sealing groove towards the other of the two opposed surfaces of the sealing groove; wherein the protrusion is of a material more rigid than a sealing material of the sealing members, or, alternatively, when no fluid pressure acts on one of the major surfaces of the gate plate, the protrusion does substantially not deform if the gate plate abuts the protrusion; wherein at least one of the valve housing halves (20a, 20b) at a top portion of the valve housing positioned above the flow opening comprises at least one support element on one or both sides of the gate plate for supporting the gate plate when a fluid pressure acts on one of the two major surfaces of the gate plate, wherein the support element/support elements is/are provided as projections that project towards the opposed valve housing half (20a, 20b), the gate valve being characterized in that the protrusion is positioned closer to the flow opening than the sealing members; and in that at least one of the at least one support element is elongated and extends along one lateral side or along both lateral sides of a stem guide slot of the associated valve housing half (20a, 20b). a plate-shaped valve housing comprising two plate-shaped valve housing halves (20a, 20b), the valve housing circumscribing a flow opening extending between two major surfaces (21, 22) of the valve housing; a first pipe connected to a first of the two major surfaces (21, 22) to circumscribe the flow opening at the first major surface and a second pipe connected to a second of the two major surfaces (21, 22) to circumscribe the flow opening at the second major surface; and a gate plate slideable within the valve housing between a closed position, in which the gate plate blocks the flow opening, and an open position, which allows fluid flow through the flow opening; wherein the valve housing comprises a circumferential sealing groove, the sealing groove at least partially circumscribing the flow opening, the gate plate sliding in the sealing groove when sliding between the open position and the closed position, the sealing groove comprising two opposed surfaces, two opposed circumferential sealing members each extending from one of the two opposed surfaces to abut an associated one of two major surfaces of the gate plate for sealing the flow opening at least in the closed position; and wherein a protrusion extends from one of the two opposed surfaces of the sealing groove towards the other of the two opposed surfaces of the sealing groove; wherein the protrusion is of a material more rigid than a sealing material of the sealing members, or, alternatively, when no fluid pressure acts on one of the major surfaces of the gate plate, the protrusion does substantially not deform if the gate plate abuts the protrusion; wherein at least one of the valve housing halves (20a, 20b) at a top portion of the valve housing positioned above the flow opening comprises at least one support element on one or both sides of the gate plate for supporting the gate plate when a fluid pressure acts on one of the two major surfaces of the gate plate, wherein the support element/support elements is/are provided as projections that project towards the opposed valve housing half (20a, 20b), the gate valve being characterized in that the protrusion is positioned closer to the flow opening than the sealing members; and in that at least one of the at least one support element is elongated and extends along one lateral side or along both lateral sides of a stem guide slot of the associated valve housing half (20a, 20b).