Abstract: A valve for regulating the passage of a fluid through pipes, in particular pipes having a large diameter, has a valve housing and a valve unit. The valve unit includes a spindle movable in vertical direction in the housing and is connected to a valve disk which reciprocates in a flow cylinder having a perforated casing. The spindle is further connected to a lifting cylinder which provides the movement of the spindle and the valve disk between a shutoff position and an open position. The valve unit of the valve is insertable into the housing and removable therefrom in its entirety without necessitating a dismantling of the housing.