FLYING VALVE FOR A FREE PISTON

The invention relates to oil and gas production and can be used for lifti ng a fluid from a well by using a gas power. The inventive flying valve for a free piston comprises a tubular body, a detachable element, which is inser table therein and is embodied in a form of a solid of rotation, and an arres ter used for limiting the detachable element travel. The arrester is embodie d in the form of a ring, the diameter of which is less than the internal dia meter of the tubular body and is arranged coaxially therein. The thickness o f the walls of the annular arrester gradually increases in the direction of the detachable element and the top and lower edges thereof are rounded. The arrester can be embodied in one piece with the tubular body and connected th ereto by means of one or more connecting straps. Said arrester can be also e mbodied in the form of a separate part provided with at least two fixing pro jections. The tubular body is made of a flexible elastic material and the wa ll thereof is provided with holes matching the shape of the fixing projectio ns of the arrester which are insertable therein.