The main advantage of the S-shaped pipe valve is that the swinging nozzle is flat, easy to adjust after wear, and its sealing performance is very good, so the S-shaped pipe valve pump has a higher delivery height than the gate valve pump of the same specification. The design is based on the principle of parabola, which makes the material flow more reasonable and further reduces the resistance, and the AS-shaped pipe valve is the most widely used concrete distribution valve at present. Its main features are simple structure, smooth flow path, and small flow resistance of concrete. Good sealing performance and high pumping pressure: the height of the hopper from the ground is low, which is convenient for the concrete mixer truck to unload to the hopper; the reversing speed is fast and the noise is low.