The valve body is formed by casting or die-casting, and its logo is cast or die-cast on the valve body at the same time as the valve body. When the shape of the valve body is formed by die forging, in addition to die-forging or die-casting at the same time as the valve body, the marker can also be marked on the valve body by imprinting. When the shape of the valve body is processed with forgings, steel pipes or steel plates are welded, in addition to imprinting, other methods that do not affect the performance of the valve body can be used.The valve body is formed by casting or die-casting, and its logo is cast or die-cast on the valve body at the same time as the valve body. When the shape of the valve body is formed by die forging, in addition to die-forging or die-casting at the same time as the valve body, the marker can also be marked on the valve body by imprinting. When the shape of the valve body is processed with forgings, steel pipes or steel plates are welded, in addition to imprinting, other methods that do not affect the performance of the valve body can be used.