Main valve element for reversing valve

The invention relates to a main valve element of a reversing valve, and belongs to the technical field of machining of alloy materials. The main valve element of the reversing valve comprises an upper valve bush, a lower valve bush and a valve element body. The lower valve bush is inserted into the upper valve bush and connected with the upper valve bush. A piston is arranged in the upper valve bush. The valve element body is located in the lower valve bush and stretches into the piston. The upper valve bush is provided with an opening, and the opening is covered with an end cover. Main parts of the upper valve bush, the lower valve bush and the valve element body are made of alloy steel, and the surface layers of the main parts are doped with additives, the additives include one or more of carbon fibers, ceramic fibers, titanium nitride, silica and calcium carbonate, and the weight of the additives accounts for 0.2%-0.5% of the total weight of the main parts. The main parts of the upper valve bush, the lower valve bush and the valve element body of the main valve element are made of alloy steel in reasonable proportion, and the specific additives are added to the surface layers of the main parts, so that a dual protection structure is formed; and sealing rings made of composite materials are arranged on the surface of the lower valve bush and the surface of the upper valve bush, so that the lower valve bush and the upper valve bush have good protective capacity and corrosion resistance.