In a valve assembly (1) comprising a valve housing (2), a valve seat (3) and a valve body (4) adapted to fit in closing relationship in said valve seat (3) in a closed position, said housing (2) has an inlet (5) and an outlet (6) for a pressurized fluid, positioned upstream and downstream of the valve members, respectively. The valve has a closed position being maintained by a closing force e.g. from a compression spring (7) and an open position, wherein the valve seat (3) and/or the valve body (4) are moved away from each other by an activating mechanism. A pressure balancing line (11) is provided internally or externally of the housing (2), wherein fluid of the fluid flow downstream of the moveable valve member (3, 4) is in fluid connection with the opposite end of said member, when in use.