A safety valve for a hydrocarbon wellbore includes a valve housing; a tubular valve member having an axially extending tube wall; and an operating mechanism for operating the valve member. The housing has a passage extending from a lower opening to an upper opening. The tube wall has one or more radial inlet apertures therethrough. The lower end part of the tube wall is closed. The valve member is axially movable in the passage between a flow position and a blocking position. In blocking position, the valve member is retracted in the housing such that the inlet apertures lie inside the housing and fluid flow between the lower opening and upper opening is prevented by the closed lower end part of the valve member. In the flow position, the valve member projects below the housing such that the one or more radial inlet apertures lie outside the housing.