The invention relates to a valve, in particular to a valve for a petrochemical exploitation ship. The valve comprises a flat seat, a fixing frame, a connector assembly, a valve shell, a gate plate anda valve side cover. The connector assembly in the valve can rotate, a connector pipe on the connector assembly can be connected with an external pipeline with one size, and the external pipeline canbe directly connected to an inner thread connected ring at the upper end of a circular pipe without using the connector assembly so that a connector in the upper end of the valve can be connected withtwo sizes of external pipelines; and when the valve is opened, a side connecting pipe can be controlled to be opened through the gate plate, the side connecting pipe and a lower connecting pipe can be controlled to be opened simultaneously through the gate plate, and thus the valve becomes a three-way valve. The fixing frame is slidably connected to the left end of the flat seat, the connector assembly is connected to the flat seat in a hinged mode, the valve shell is fixedly connected to the lower end of the flat seat, the gate plate is slidably connected to the valve shell, and the valve side cover is fixedly connected to the front end of the valve shell.