The fluid resistance is small, opening and closing the required external force smaller; medium flow is not restricted. When we open fully, the sealing surface by the working medium erosion than the cut-off valve is small; shape is relatively simple, casting process is better. Forged steel gate valve fluid resistance is small, forged steel gate valve body shape is simple, short structure length, wide range of applications. Forged steel gate valve is placed vertically in the valve body, and check valve flap is placed horizontally inside the valve body, and thus the length of the structure is shorter than check valve. forged steel gate valve body medium channel is straight, so the fluid resistance is small.